surroundedbyair

The Gut

2012-01-24T20:24:00.000-08:00

The nerves of the gut know when essence is too low.

They steal essence from the brain.

Fuel gets low. The ceiling gets low. Salary gets low.

Clear thought decreases.

Turbulence increases. Fatigue increases. The scorn from the corner office increases.

Errors increase.

A pilot, told to ignore a broken nav light,

Feels his essence drain away with the daylight.

Cancel and lose my job?

Fly and lose my license?

Worse, fly unlit and strike another craft?

No essence remains after questions such as these.

Flying Fun Food Friends Family and Photos

2012-01-22T20:29:00.000-08:00

The flying business has been a little s-l-o-w around here lately, partly because of lots of demand from my day job, and partly because of little things: one student's airplane is out of annual, a pilot needing an Instrument Proficiency Check has to repair his glideslope receiver first, a pilot with an incomplete Flight Review is ... too busy? Really?

So I was missing being in the air. And then there was the $500 I was owed that arrived.

But I hate to just bore holes in the sky, so I needed a mission. The meaning of "mission" depends heavily on context. For many in this primarily Mormon community, it means a church calling. For military types I guess it means a flight to get the enemy. To me it means: tax deductible.

Last night, a large Coronal Mass Ejection (CME) hit the Earth, disrupting the ionosphere and interfering with geostationary satellites. (A CME is a big chunk of the Sun; read more about them here.) So my mission was to collect data on GPS performance.

Wink, wink.

Now it being a reasonably nice weekend day there are other things to attend to besides flying. So, I had to go check out the local ski area, even though my hip has been acting up. We've had very little snow this winter (see the picture), and the locals have been getting restless. Our local ski area was finally open. I just had to go by.

And, despite the hip, I need some exercise.

And usually I do the family's grocery shopping on Sunday. How was I going to fit all of this in?

So after a look at the ski area I headed up to Blackfoot. Blackfoot has a large Hispanic community and is the place to go for good Mexican ingredients, and the store is within walking distance of the airport. So I walked to the store, filled a bag with dried chilis and queso fresco and a jalapeno and cilantro, and walked back to the plane.

Well, sort of. My friend Richard was puttering around in his hangar, so I stopped in to visit.

The GPS worked perfectly throughout the flight.

So: data collection, skiing, walking, cooking, shopping, visiting with friends, taking pictures, and flying.

And I did it all in 0.9 on the Hobbs!

Local versus Global

2011-12-31T14:28:00.000-08:00

Pilots always carried maps aloft. Cars and railroads led the way.
Flags were flown, lamps were lit, water towers proclaiming
the town of White Pigeon circled.

In computing it's a local search. One small step, then another, then another, until
the way to the destination is clear. No giant leaps. The plan is vague.

Bellamy taught a different way. Use the wind. Not the local wind,
that tips a craft as it touches down, but the wind in the air.

The Sun warms a spot on the ground, air rises, increasing
essence. Air moves in to replace it, more essence.

The Earth turns. The inrush of air whirls as well, to the right in the
North, to the left in the South.

Bellamy showed how to join the circle, to gyre
and gimbal, to draw essence from the wind.

One giant leap. More than an infinitude of small steps.

But small steps matter. The craft must turn to stay within the circle.

The pressure of expediency broke the pattern. The navigator retired. The wind is ignored. The approach is more direct, one long step, turning to verify Mercator's equations.

The circle is squared.

Essence is lost.

Cloud Phase

2011-12-27T22:50:00.000-08:00

As a rule, I don't like to write about accidents; I prefer to write about preventing them. Still, I read about accidents, and I was interested in Scott Dennstaedt's analysis of the weather factors in last week's tragic crash of a TBM-700 in New Jersey. I have a little TBM-700 time, working with an owner who wanted to get his ATP who quickly realized that it was far more cost effective to do so in a simulator. It's an amazingly capable airplane.

But, as I said, I don't write about accidents.

Dennstaedt's analysis of the weather factors included a weather "product" (as the National Weather Service people call it) that's new to me, the Cloud Phase chart. It took me a second to realize what this means: in chemistry we learn that matter is generally in one of three phases, solid, liquid, or gas. So the cloud phase refers to the water in the cloud. If it's solid, that's ice, which is less likely to stick to an airframe; if it's liquid, though, and cold enough, then it is more likely to stick to the airplane and freeze.

Here's a recent example, showing the cloud phases for the Eastern USA. The most important color is baby blue, indicating cold liquid water. The Ohio Valley, Michigan, and northern New England have cold liquid water clouds.

Compare that with the "Maximum Icing Severity Chart" available from aviationweather.gov. This shows the potential for heavy ice throughout the Ohio Valley, Michigan, and northern New England, with SLD (Supercooled Liquid Droplets) potential in northern New England. This seems to be associated with an occluded front that runs from a low centered near Kingston, Ontario (CYGK) that runs to New York City (KJFK), which becomes a cold front that seems to be forming a wave off the DelMarVa peninsula off Dover, Delaware (KDOV).

It should be obvious that low pressure over a Great Lake will form ice, but in cases where the situation is less obvious the cloud phase chart could be a useful aid in making a go-no go decision.

Now here's the trick: it's really hard to find the chart. I finally found it at a NASA-Langley website. Click on the Conus links under GOES EAST or GOES WEST, then use a drop-down menu to access the Cloud Phase chart.

Not easy, but nothing about icing is ever easy.

Lost

2011-12-20T21:52:00.000-08:00

According to this article on AirTrafficManagement.net, as well as others, the Federal Aviation Administration is getting serious about decommisioning as many VHF Omni-Range (VOR) stations as possible, leaving behind a skeleton system in case of GPS failure. This is a testament to the success of the GPS and WAAS programs, which have demonstrated their utility and reliability over, what, millions of flight hours?

I'm an old-fashioned guy: yes, I own a sextant, but the last time I tried to take a sight I had to knock on my neighbor's door and ask when he had moved to Montana (and that was so long ago that he has since moved to Utah). But I don't use the sextant in flight, and in fact with the rise of tablet apps (I've been using both Skycharts and FltPlan.com), I don't use paper anymore, either. I have a current sectional chart for my local flying area, and current Low/Enroute IFR charts, but when those expire I will probably switch to WAC charts for "emergency" back up. I use a yoke-mounted VFR GPS for navigation, which merely supplements the VOR/DME for IFR flight, of course (our club can't afford a panel mount GPS right now).

One other thing: I miss keeping a paper navigation log, but have found a nice hack: make a pdf of the navigation log from whatever source you like, and open it in uPad, another app. This allows me to write on the nav log, noting clearance, OOOI times (Out-Off-On-In), time-of-station-passage, times when I switched tanks, and the like.

Do you have trouble remembering the ATIS code? I form the letter in American Sign Language; that little bit of multi-modal memory manipulation seems to do the trick. Some pilots "write" the ATIS code on the yoke with a finger. Same idea. As for the ATIS content, I set the altimeter, so there's no need to write that down, and then pull up the approach to the runway in use, so there is no need to write that down, either.

But back to the VORs. I still use them!, even when flying VFR. I know I'm not supposed to, but I hearken back to this advice from Bowditch's American Practical Navigator, available online from Wikisource:

[Navigation] includes the routine use of several different navigational techniques, both as operational checks and to maintain skills which might be needed in an emergency. Any single navigational system constitutes a single point of failure, which must be backed up with another source to ensure the safety of the vessel.

So I still tune VORs.

Many years ago, when airliners had VOR and DME (no groundspeed) and ADF, I was a passenger on a United flight to San Diego, dutifully listening to Channel 9 (United puts ATC on its entertainment system). The whole way from Chicago the Morse letter 'W' could be heard in the background. What was 'W'? Checking the charts when I got home, I saw that 'W' was a powerful marine beacon located at Point Loma, near Lindbergh Field. Somebody up front wanted to have a needle pointing to San Diego for the whole trip...

Alas, marine beacons have disappeared from aeronautical charts. The most interesting area was Long Island Sound, where all of the beacons were on the same frequency but transmitted on a schedule. Thus, you could triangulate with a single receiver: one line of position from beacon #1, the next minute a LOP from beacon #2, the next from #3, and there you were!

Here you see an old (1989) Sectional Chart Legend, showing the beacon in question and how to use it. The "H+00 & ev6m" for Point Loma beacon (identifier W) indicated that it broadcast for the first minute of the hour, then every 6 minutes. So, if your watch was accurate, and the time was H+06, you knew that you were listening to Point Loma. There were other beacons along the coast, with broadcast schedules "H+01", "H+02", etc.

Some people used these.

Some people still tune VORs.

Some people still tune ADFs.

Some people take comfort in seeing the the appropriate constellation ahead.

Not just me.

BUT, the question is whether this is worth the expense of maintaining all of
those stations. (I'm not suggesting that we decomission the North Star!)

Probably not.

Unusual Attitudes

2011-12-16T22:15:00.000-08:00

It seems to be BFR season, and today's pilot surprised me a little. In a good way!

First, the weather was a little bit of a concern. How bad was it? The ceiling was 2,000' overcast and the visibility was at least 10 statute miles, and as I told him later in large parts of the USA that was as good as it ever got. But our situation is a little bit different, because we are spoiled rotten. We either have severe clear or very low IFR.

About 20 miles east of Pocatello there's an 8,900' mountain; we could not see it. Twenty miles is pretty far if you are paying attention, but it was a revealing moment: VFR doesn't mean that you can see everything.

The best BFR expands the pilot's skills, so we planned a little local flight to get him more familiar with flying without full disclosure. Then he surprised me again:

"I want to practice unusual attitudes. Under the hood. It's been a while..."

It had been; he hadn't been under the hood since 2003! This trend of giving BFRs without hood time is disturbing. Is it a local problem or a national trend? VFR-into-IFR is a major cause of accidents, so let's make sure that pilots have the skill to fly out of the clouds.

(The Light Sport syllabus has no hood time. Some LSA aircraft have no gyros, so it might seem superfluous, but it is possible to use a GPS receiver to stay upright. We should teach pilots how to do it!)

But this pilot wanted more than a signature for his BFR; he wanted an actual review! Needless to say, this is an "unusual attitude."
So we reviewed the procedures for unusual attitude recovery and went out and practiced. The key instrument in unusual attitude recovey is the airspeed indicator, because the attitude indicator may have tumbled. That took him a little getting used to. Then we flew around the area in "reduced" (10 mile) visibility, using the autopilot to keep the airplane upright (with the snow in the hills there was no real horizon) and leave some cognitive ability available.

The rest of the flight was pretty standard, but I sure enjoyed the unusual attitude.

Fun

2011-12-12T19:45:00.000-08:00

The craft follows the river, in a canyon, perhaps only imaginary.

The river twists, the craft turns. The river turns, the craft twists.

The stick is caressed, or pulled.

The rudder cannot keep up. Essence is dribbled away.

The pilot feels the happiness of the fishes.

Fun costs money.

Flight Review

2011-12-11T11:39:00.000-08:00

Here in the USA, pilots are required to have a flight review (61.56) with an instructor every two years (hence the acronym BFR, for Biennial Flight Review). Pilots flying under 14CFR135 - that is, charter pilots - are required to take an annual review (135.293) from an FAA-designated Check Airman in every type of aircraft they fly. Over the past ten years, most of my flight instruction has been flight review of one kind or another (I was a Check Airman for a 135 operator for many years). While 61.56 leaves everything to the instructor's discretion (which could mean a bottle of Jack Daniels and a recent photo of the pilot in an aircraft), 135.293 (supplemented by FAA manuals) provides a lot more detail of what's required.

So what happens when I sit down to do a BFR with a private pilot? The first thing I keep in mind is the old saying from John and Martha King: "Don't hit anything, and don't stall." But as usual the devil is in the details.

The ground exercise is to have the pilot plan a cross-country. "Don't you have a maiden aunt in Seattle that you visit?" Planning a flight from eastern Idaho to Seattle enables us to review runway requirements, weather, airspace, special use airspace, runway incursion avoidance, fuel management, TFRs, oxygen use, currency ("recent experience"), and a host of other operating rules and practices.

The other thing is that the world of flight planning is changing rapidly: I developed a new iPad flight planning hack on Friday, which I'll write about after I try it in anger.

"Do a weight-and-balance, too, please." That one explains itself. The key thing I want to review is the shocking effect of high weight on performance.

And now comes the first problem: too many pilots show up at the airport without the flight planning and without the weight-and-balance. Now I'm going to have to charge you for my time while you do it. And, we'll be pushing daylight and everyone's busy schedules. It's likely that the flying part will have to be postponed.

[I recently tried to do a night BFR with a pilot who did not have an instrument rating. This was not a good idea. The only part that went well was when he was practicing instrument flying "under the hood."]

What about the flying part? I worry about the things that cause accidents, which are well-known to be loss of control, VFR-into-IFR, fuel management, and low level maneuvering. So the typical flight goes like this:

Fly to the practice area under the hood. Do some standard rate turns. [During a recent BFR I noticed that nobody had put the pilot under the hood since 1999!]
Steep turns. [This addresses basic handling. It usually goes OK.]
Stalls and slow flight
engine failure. [This generally goes poorly because pilots haven't thought about it in two years. I now think I should review this on the ground before we fly, because we often have to do it over in flight. I worry more about choosing a field and setting up a good approach than about best glide speed, since glide performance is rather robust. I spent yesterday down low looking at several lines of wires between us and the "chosen" (actually, default by that point) field.]
Turns around a point. [A little review of safe low level maneuvering]
Traffic patterns

I developed a standard evaluation flight for 135 pilots that works well for Instrument Proficiency Checks. It goes like this, almost all under the hood.

Steep turns
Stalls
Unpublished hold. [If a pilot has problems with orientation this will expose them. I recently did a published-but-unfamiliar hold during a practice session and was surprised at how difficult it was.]
ILS approach to a missed approach
engine failure: in a twin this happens climbing through 500' AGL, in a single it happens on the downwind

This is not a complete check, but it tells us what to focus on for the rest of the check.

Did I miss anything?

Wind shear

2011-11-30T11:02:00.000-08:00

I was reminded about the subtlety of wind shear during an IFR proficiency flight last night. We tend to think of wind shear as the evil microburst that brought down a Delta L-1011, but that is an extreme.

I did an ILS to runway 21 with reported surface wind 050 at 5. The POH says the airplane can stop in the runway available with that tailwind, but other traffic meant that I was only going to do a low approach.

The winds aloft were calm or light (based on GPS groundspeed), but at about 300' AGL I started to lose the glideslope, which is (I like to think) unlike me, and if nothing else embarassing when my friends see it. I tried to adjust the descent rate to catch the glideslope (I got to about 1/2 deflection) but reached Decision Altitude before the glideslope needle centered again. OK, a decent but not great approach.

We went around as planned and entered on left base for runway 3 behind the traffic, and I finally figured it out: I was crabbing to the right while flying a square left base; the wind above 300' was from the southwest, but the surface wind was from the northeast.

Wind shear!

So my ILS problem was the classic response when a headwind shears to a tailwind: I got above the glideslope. Just like the books say.

The shear was weak, not strong, so not enough to keep from completing the approach. In fact, the shear was so weak that I wouldn't have been looking for it even if I had been looking for it! But its effects were measurable, though not dangerous. So there's no point in beating myself for not noticing it.

Yeah, right.

Amarillo

2011-11-24T20:08:00.000-08:00

More from my study of essence...I hesitate to call it poetry.

Amarillo

Amarillo.

Life in a country song.

Hurry to the airplane, weather coming.

The wind shifts as we taxi east.

Now west from Amarillo, still on the ground.

Fuel, movement, noise, essence put to good use.

Break ground and ride the bull.

Eight seconds, still we ride the bull. Up, down,left, right, all at once. Close mouth to save tongue.

Eight more.

Yet another eight.

The bull lets go, we are tossed straight up.

We climb and climb and climb, gaining essence without bound.

Such is the power of the Blue Norther.

Wind

2011-11-23T20:15:00.000-08:00

We'd had an easy time with ground portion of the Flight Review, and now we headed out onto the ramp to do the preflight in the calm early evening air.

"See," I said, "the forecast was for the wind to die down right about now!" Famous last words...

We started up and taxied out, the wind favoring a long-ago-closed runway, but light enough to be of no consequence. We taxied into the runup areas while a commuter and freighter taxied our way.

"AmFlight blah-blah-blah, a few minutes ago an arriving twin Cessna reported moderate turbulence below 2000AGL," ground announced.

"Roger," came the Amflight's reply. Freight Dog. Going anyway. The boxes don't complain.

"SkyWest blah-blah-blah, did you copy the report of moderate turbulence."

"Affirmative."

The freighter launched. The Brasilia launched. Now it was our turn.

"Be aware of wake turbulence," the instructor in me said as we started the roll.

BLAM!

As soon as we were airborne the turbulence kicked in. And kicked again. And kicked harder! This was as rough as I'd flown in in many years.

We climbed into smooth air for a little airwork, then headed back to the pattern.

BLAM!

As soon as we descended to 2,000' AGL the turbulence kicked in. And kicked again. And kicked harder! Our first approach was a mess, and we went around early. The second was better, and he did a good job, landing on the centerline in extremely variable winds, while I stayed loose but alert.

As we rolled out we looked at each other and said, almost simultaneously, "I'm done for today, how about you?"

And so we were.

HazMat

2011-11-21T14:26:00.000-08:00

The craft carries animal, vegetable, and mineral.

Animals, meat, brains, producers and consumers of essence.

Vegetables, cotton fibres and canvas sacks. Canapes, carrots, cloth coats.

Minerals, fuel, fabrics made from the source of fuel, clothes fashioned from the source of fuel.
But not the only chemicals.

Acetone, butane, carbon tetrachloride, Duraflame logs, Ethanol, Fire starters, grease, halo-gen, iodine, Jim Beam, ketone, Listerine, mescal, nitroglycerine, oxycontin, pectin, quinine, rye whisky, Saran Wrap, TNT, universal solvent, Velveeta, White Lighning, Xylitol, yerba maté, Zoloft.

More.

Hydrochloric acid in the aircraft battery, hydraulic fluid, deice fluid.

Medicines, contact lens solution, volatiles. Cough syrup. Heroin. Belladonna. Valium.

Alcohol, to drink. Not by the crew.

Durians. Limberger cheese. Even gorgonzola.

Baby wipes, Febreeze, lip balm, moustache wax.

Very old coffee.

Fermenting grapes a passenger left behind.

Fire extinguishers, designed to suck the oxygen out of fire, might suck it out of a pilot as well.

Batteries. AA, AAA, D. Metal oxide. Lithium. Sodium. Nickel. Cadmium. Coleman fuel, white gas, stove fuel, lighter fluid, aftershave, Flares, smudge pots, drip lanterns, sterno.

The pilot spends essence watching for these things. It may not be enough, and the pilot spends sleepless nights as well.

Astronaut Applications

2011-11-16T21:23:00.000-08:00

NASA is looking for a new astronaut class (they'll ride to the ISS in a Soyuz). More information is available here.

I applied in 1990 or so, but never heard back. I'm more qualified now, but I doubt that I could pass the "long duration space flight physical" after a bypass, two stents, and the development of rheumatoid arthritis.

OTOH, I have a second class medical certificate, and NASA uses an FAA medical as a pre-screen. For many years after the bypass I had a first class medical, and went on to become about the only part-time post-bypass Math Professor King Air captain in history; I'm familiar with ignoring "impossible."

So somebody please talk me out of applying again.

Quick Jet Intro

2011-11-10T17:30:00.000-08:00

A student called me this afternoon, bursting with excitement. He's always bursting with excitement when it comes to flying.

"I've got a chance to ride up front in a jet tomorrow," he said, "What should I look for?" I could hear that he was grinning from ear to ear.

Wow, what a question! Most of his flying has been in two-seaters; that's a big leap. Those of us who have made it know how far behind the airplane he's going to be.

Here's what I came up with:

Listen to how ATC and professional pilots are clear but concise, and use standard phraseology.
Watch the groundspeed readout from the FMS (I think it has a UNS-1 system). Convert the speed to miles-per-minute. This is important for everybody: planning a 50 mile descent at 360 knots is hard; planning a 50 mile descent at 6 miles/min is a lot easier.
Study the arrival chart to get an idea of courses, speeds, and altitudes in the terminal area.

And, two more things:

Make sure to get a good look at the Grand Canyon!
Tell the captain that his instructor (me!) is available for copilot duties!

Did I miss anything?

Quit Stalling on Stalls

2011-11-06T11:24:00.000-08:00

At the EASA Safety Conference, held in October 2011 in Cologne, Airbus came out strongly on how to handle stalls in their aircraft.

Apply nose down pitch control

The full presentation is here.

Now if only we could find some politicians who would listen to reality and do the right thing...

Low and Slow

2011-11-01T18:21:00.000-07:00

I was returning from my weekly commute to our other campus. The Archer is in for its annual, so I was in the Cherokee Six, hauling around five empty seats.

Now I'm coming home, tired from teaching and the 5 miles of walking to and from campus, headed directly into the Sun. I enter on downwind and reach down to the flap lever. It doesn't feel right. The flaps are going down but not staying down.

I start to fuss with the button, to see if they'll stay down if I pull a little to the left, or if I pull a little to the right, thinking that they had worked on departure...and all the time I'm descending.

"OK, you're low, quit fooling around, diagnose the problem on the ground." I said this out loud.

I did a no-flap landing (adding 10 to Vref, just a guess, no way to compute it while flying that low).

After I landed I got the button unstuck.

No accident today.

And this is one of the few times I can remember when the freight dog excuse "But it was working when I took off!" has actually been true.

Leveling Off

2011-10-28T10:49:00.000-07:00

[Another few words from my work on using essence and finesse to think about flying]

Levelland, Texas. The Llano Estacado. Cattle, oil, essence for pilot and craft. Cruising above the Caprock. Easy.

Start on the ground. Fuel, noise, sublimation.

Climb. Speed, check. Vertical speed, check. Chemical essence turns to height. The textbooks say nothing is changing, but the ground falls away, the air thins. The needles slip from truth
to lies.

Now make it all stop. But how? Push the nose down, lose finesse? Pull the throttle back, save essence? Both must change.

As height increase, speed is low. As speed is low, height increases.

But height stops growing. So speed must grow. Change of finesse. Gently push the nose to level.

Now speed is growing. Drag grows, not lift. Continue and finesse will vanish.

Level, using more essence robs the craft of finesse. A double dilemma. Everything we have worked for, scrimped for, sacrificed for, thrown away.

My candle burns at both ends.
It will not last the night.

It will not last to shed a lovely light.

Pull the throttle back.

[poem from Edna St.-Vincent Millay]

Thermals

2011-10-11T22:08:00.000-07:00

Some days the clouds pass in echelon, regular as a hearbeat.
Someplace upwind energy pools in the auricle,
a bundle of hiss waiting to signal a contraction.
Enough energy pools and the lifeblood bubble upwards,
leaving a void.

The energy pools in the auricle, ready to repeat.

Those who soar know this cycle.
The auricle might be a darker field, a rock, a stock pond.

The dome above fills and bubbles, fills and bubbles.

The time seems geologic compared to the time of the heart,
but the glider pilot holds his ear against his lover's chest,
waiting for the heart to beat again.

Finessing Failure

2011-10-08T20:33:00.000-07:00

Engines fail, and pilots since the Vickers Vimy have worked hard to handle this safely.

A standard part of multiengine training is the drag demo. You pick a reasonable airspeed and set the power to fly level. Then, put the landing gear down; after a few transients, the airplane settles into a steady descent rate. "Write that down: gear down is 500 feet per minute," or whatever.

After you do the same thing with flaps, you go on to see what happens with a windmilling propeller, and finally with a windmilling propeller in the zero-sideslip configuration. (In a multiengine airplane with asymmetric thrust, flying with the wings level amounts to a mild slip, as a yaw string will clearly demonstrate.)

The student gets a lot of good knowledge out of this demonstration: windmilling propellers produce a lot of drag (in most multis it is about the same as the landing gear), and zero-sideslip really improves performance.

Too bad we're teaching the wrong thing.

For the past little while I have been rethinking all of the problems of aerodynamics from the point of view of two parameters, essence and finesse. (I've written about this here and here, among other places.) Briefly, essence is composed of all of the energy (potential, kinetic, chemical, intellectual, emotional) available to the airplane. Finesse is simpler; it's simply the glide ratio at the current speed, something a glider pilot learns from the polar.

So what does a multiengine pilot faced with a failed engine need to know? The descent rate is in feet per minute, which might be useful if the pilot wants to be able to stay aloft until, say, the earthquake ends. But that's not usually the concern; the concern is Can I make it to the airport?, and the proper number to know is measured in feet per foot; it's finesse.

The thing is that finesse is quite easy to calculate, even among those who don't like to calculate. The key fact involved is that 1 knot is very close to being 100 feet per minute, so the vertical speed indicator pointing to 600fpm is also pointing to 6 knots. So, to find the finesse, divide the airspeed by the VSI reading. Done. You can refine this by considering true airspeed, but this way your estimated glide ratio is lower, ie, more conservative.

Ground speed is another matter, so if you want the best effective finesse divide GPS groundspeed by the VIS reading.

It is worth remembering that a 3 degree descent angle is a 20:1 glide ration; that's the same fact as the fact that the target descent rate for an ILS approach is 5 times the groundspeed.

The essence of an engine failure is more complex, no matter how many engines there are. One thing is sure: panic makes no essence available, which is why regular practice is essential.

One other thing: with an engine failure the chemical energy -- fuel -- that the airplane carries become ballast, ballast that burns. Be careful.

Oil Pressure

2011-09-26T11:33:00.000-07:00

Dale starts every flight with a prayer, and yesterday morning he prayed for good judgment. We were headed out to explore the local grass strips in the Ercoupe.

We flipped a coin to see who got the left seat, and I won. Last time we flew together he got the left seat, so I figure he'll get it for our next flight.

Our first stop was the beautiful Rainbow Ranch and its lovely turf. Dale did a nice landing and as we rolled out I scanned the obstacles to the West: the East is a small ridgeline, more than the 'Coupe can outclimb. I took the controls and we taxied back to the far end. "Tail in the Weeds!"

Throttle in and we're rolling. Airspeed alive. Check the engine gauges.

What?? Why is the oil pressure so low?? I aborted.

We taxied away from the owner's home so I could do a runup. We had oil pressure but less than desired. The temperature was rock steady and not too high.

What had we prayed for?

That killed the plan for exploring grass strips. We would either stay at Rainbow Ranch, or fly home. Which? This was on the edge: we had oil pressure, it was steady, and the oil temperature wasn't rising. Perhaps a stuck relief valve? Grounding the airplane at RR was an unattractive option, but not doing so required judgment.

We had enough runway and were surrounded by excellent landing fields, so an engine failure on takeoff wasn't that big a deal. We would climb out at Vx, watch the temp and pressure, and fly home a little higher to increase our landing options. We would not overfly the one town between the RR and home. There were dozens of fields in which to land, almost too many.

It was my takeoff and we launched. The pressure held steady and we climbed to altitude. The air was so smooth that I flew hands off, but more so I could focus on the terrain around us.

Quite soon home was in sight. The wind was calm, so we could choose the better way to land. If the engine quit landing north, we would be in the Walmart parking lot, but if it quit landing south we would be on the empty golf course. An easy choice.

I entered the pattern high to double check the sock. The pressure held steady. I flew a close-in downwind and announced a landing point about 1/3 of the way down the runway, aiming a little long on purpose.

We landed on the spot.

Now to figure out what's wrong.

More on the Ercoupe

2011-09-18T20:10:00.000-07:00

I was privileged to attend EAA 1114's breakfast meeting at the beautiful Cox Airfield (NC81) last Saturday. The speaker was Skip Carden, Executive Director of the Ercoupe Owner's Association, who gave his personal reminiscences of Fred Weick and the development of the 'Coupe. A couple of interesting tidbits. Several owners had their 'Coupes on display, so after the talk we all got to go look. Multi-modal knowledge sticks the longest...

[*] The 'Coupe was built back-to-fron and front-to-back simulataneously, meeting in the middle. Then the two halves were riveted together, just aft of the baggage compartment. That's why the rear section rivets over the front section. Look at one: it's true!

[*] The hat shelf was sloped so anything heavy on it would fall into the baggage compartment, preventing an aft CG. That's important: an aft CG reduces elevator authority and thus makes it harder to recover from a stall.

[*] A 1941 CalTech research project put JATO (Jet-Assisted TakeOff) bottle rockets under the wings. These weren't very powerful (I think it was 30 pounds of thrust for 12 seconds), so it wasn't the dramatic Fat Albert JATO takeoff you've seen at Blue Angels shows. But they still got interesting data.

[*] We got to see a film of the only twin Ercoupe: two airplanes bolted together with a center section replacing the left wing of the right fuselage and the right wing of the left fuselage.

I'm trying to put together a plan to fly into NC81 later this week. It will involve some luck, but I'm planning to try hard.

Finding Finesse

2011-09-11T13:37:00.000-07:00

[This is another short essay exploring the roles of essence and finesse in aeronautics. Remember that "essence" is largely energy, while "finesse" is lift over drag.]

Asking how the pilot sees finesse evolving starts with asking how the pilot sees finesse.

Seeing finesse is easiest when the ship has no power. Keep your speed steady. Pick a bug on the windshield, and make a mental note of what it hid on the ground. Say it's a haystack; focus on the haystack. If the haystack falls below the bug, your glide will go beyond, and if the haystack moves above the bug, your glide will fall short.

Keep your speed steady. If you will be short, pick another dead bug further up the windshield and note the shrub that it obscures. Watch the shrub. See if it goes up or down. Pick an bug on the opposite side, and play the game again, hoping for a smooth field that moves neither up nor down.

Finesse takes you to the spot that does not move.

New Guy

2011-09-07T14:54:00.000-07:00

There's a new guy working in the tower. Oh, that won't mean much to most of you, but this is a small town and the tower chief, whom everyone calls "Tower Dan" is a good buddy. For example, I have seen him and his wife in some pretty outrageous Hallowe'en costumes. So a new guy needs to be treated with care.

I heard the new guy while taxiing out for my weekly commute. (This is not Frank's epic commute we read about at N631S, but still...).

New Guy: "Taxi to runway 3 via A and F, give way to the Mooney passing right to left."

Me: "3 via A and F, Mooney in sight."

Mooney? Oh, look, there's Jon, just leaving his hangar half a mile away. There would be time to do a runup (nothing was behind me) while I waited. Rather than chastise the new guy for making me wait, I had all of my pretakeoff checklists done before Jon waved on his way by.

So I start following Jon to runway 3. I'm thinking there's a good chance that he'll block my way while he does a runup, and I have a class to teach. (Yes, there's a touch of get-there-itis here.) I'm coming up fast on intersection D, 6000 feet TORA. This is the time to exercise the judgment I mentioned in the previous post, because I could get a big gain for minimal risk.

Me: "Ground, we'd like to depart from D." I was going to do my first intersection departure in years!

New Guy: "Taxi to runway 3 at D." I'm already there, so I quickly switch to tower.

Me: "56X, ready runway 3 at D, straight out."

New Guy: "Clear for takeoff."

I was almost clear of the Class D before Jon departed.

I wonder what the new guy will wear at Hallowe'en?

Silence of the ECAMs

2011-09-05T21:29:00.000-07:00

Unlike last year, this year's fishing trip featured sun and clear skies. I got my medical on Wednesday, but by that time all of the club airplanes were reserved. Luckily my friend Art would be passing nearby in his 210 and kindly offered (1) to stop and get me and (2) to let me do all of the flying.

We did not need the 210's ability to climb, and had a pleasant flight to Ennis, MT (KEKS). Well, pleasant except for the fact that I hadn't flown a 210 in about 5 years and was appropriately behind the airplane.

Ennis is in the Madison Valley, which, to me, is the ideal Western valley. The world-renowned Madison River flows out of Yellowstone Park and through the valley. Every year we complain about the new construction, but in fact the valley is quite empty.

The fishing, friendship, and weather were wonderful, but this morning it had to end so Art and I drove the rental car back to Ennis. The airport sits among wheat fields on a bench above the valley with dramatic mountains rising just to the East. It is often perfectly quiet, or perhaps the most noise you hear is a 172 from Bozeman practicing touch-and-goes. I enjoy this noise.

But this morning was different. A midsize jet from one of the fractional-ownership operations was on the ramp, Auxilliary Power Unit (APU) screeching loudly. I checked on flightaware, and their departure was still an hour away.

The fractionals, like the airlines, depend on standard operating procedures (SOPs) to make their operations safe and smooth. Their pilots often find themselves flying with strangers, but despite this, both of them have to have the same plan and have to react the same way. They have (or are reputed to have, although some recent events lead me to question this) well-defined Pilot-Flying and Pilot-Not-Flying roles which have been negotiated in training, so there is no confusion when something goes wrong while flying an approach to minimums.

I'll bet a noise-abatement fine at Santa Monica that this company's SOPs call for APU start long before departure. There could be a lot of reasons for this, including cooling the cabin and, more important, charging up the battery to reduce the chances of a hot start. But please, guys, have a little judgment: your APU, which is in fact louder than your airplane, was ruining the beauty of the Madison Valley for everyone.

The fractional crews always seem a little overwhelmed at mountain airports, anyway. Their mindset is tower-controlled fields in urban areas. They wander around the ramp looking for a Blackberry signal and ignoring the other pilots and airplanes. I watched the captain walk by a beautiful Super Cub without a glance!

(On our way in, another fractional warned us over UNICOM of the monster crosswind, voice dripping with fear, audibly holding himself back from telling us not to try to land there. I landed with about 1/3 control deflection, not a hairy situation at all.)

I got a briefing and filed a flight plan while Art topped the tanks. The midsize jet started to taxi to depart runway 16, unaware of the 172 in the pattern for runway 34. Luckily, the Skyhawk departed the area, and the midsize jet left to the south before turning north over the valley. Go figure.

We departed straight out, pulling the prop back as soon as it was safe (a 210 at 2700 RPM is among the loudest airplanes known). Clear of terrain and pointed in the right direction I lowered the nose for a 500fpm climb at about 130KIAS, so we got out of your hair soon after you heard us.

I took advantage of having another pilot on board to do an instrument approach, which preserved my currency. I don't get to fly with a Garmin 530 very often, but it came back pretty quickly. My scan is rusty, so I'll need more practice, but I'm sure that will be fun.

Finally...

2011-09-01T21:31:00.000-07:00

I got my medical yesterday morning (second class, since the FAA is being generous this season), but didn't use it until last night: I needed night currency (when I was a Sport pilot, night currency was moot, since Sport pilots are limited to Day VFR). This was real night currency, none of this full-Moon-on-a-snowy-evening stuff. Last night had no Moon and there was a lot of smoke around, even though the visibility stayed above 10SM the whole time.

The winds were all over the place so it was hard to fly a square pattern, but I managed good touchdowns. After two stop-and-go landings I switched to touch-and-goes, knowing that my final landing would be the third full stop.

When the tower closed I switched to left traffic and the wind was pushing me toward those unlit hills to the East. Since I was only "staying in the pattern" I had not rigged my handheld GPS with its terrain display. I don't need a terrain display, but having seen it (and verified its performance against some known threats) I know that my procedures plus the terrain display is more comfortable than procedures alone.

Fatigue set in after about an hour and I landed. I enjoyed the airport silence while I tied the airplane down. I drove home, listening to jazz. Just what an evening should be.

Finally.

Flight report

2011-08-24T12:19:00.000-07:00

My friend Dale finds a logbook to be limiting, so writes a report of every flight he takes. The other morning he and I too kthe Ercoupe around to some of the local rural strips. Here's his "logbook entry."

Jim and I plan to fly the coupe to Rainbow Ranch on Sunday morning. What time? I propose 0700, and he thinks that is early, but we finally agree on it. I wake up to thunder at 0600 and see lightning in several directions on the way to Blackfoot. Even if the weather clears I don’t intend to land on wet grass. The coupe is out of gas so I call Joel who says come and get some. Getting the plane out of the hangar requires tight S-turns. I go to start it and it will only run on prime. Then Jim tells me where to find the fuel shutoff up under and behind panel. Hiding the fuel shutoff is a security feature for this plane. Jim and I discuss the tradeoff between fuel reserve and fuel weight, and decide on 6 gallons a side, but it only takes 9 gallons, so it wasn’t as low as I thought. It is also down to 2 quarts of oil so I add some.

Jim points out that the only thing worse than two instructors flying together is three. A CFI in the back seat is worse than a backseat driver. Who will sit on what side? Neither of us cares and Jim only wants a front row seat. I haven’t had any left seat time lately so I end up there. We make the classic mistake of putting our stuff behind our own seats rather than on opposite sides, making it harder to reach. Jim reminds me to run up into the wind and establish a crab angle after takeoff. We cruise to Rainbow at 2100 rpm and I make a low pass of the runway downwind and Jim takes over to make a low pass the other way, with a lower ground speed. I propose an aerial tour of the airstrips in the Heise area and Jim agrees, but the rain is worse in that direction so we skirt IDA airspace and fly to Rigby. I make a horrible pattern entry to a low approach and come around again to land. Jim pronounces me an Ercoupe pilot for landing in a crab, and he takes over on the taxi back and does a circuit of his own. Terry Kofoed is getting his plane out during all of this, but he isn’t on the radio by the time we depart. Where to next? The weather is such that flying toward the blue sky is the best course and it is clear toward Roberts, so we fly by Nyle Tanner’s strip. From here we fly a mag compass course around IDA on our way back to Blackfoot. At 10 miles south of Idaho Falls we hear an inbound Columbia give the same position report, so it seems a good idea to inform IDA of our presence. There are several errors in the relayed information, but the Columbia says he has us on TCAS and we avoid a collision. Back at U02 we make 1 landing each in a gusty crosswind for 2.1 hours total. We would refuel the plane but Joel is gone so we leave some cash in the kitty. We would go out to breakfast but can’t find a place open. My flying has been sloppy this morning and Jim has pointed out a few of my errors, but not all of them. He intends to log the time as dual given which is entirely appropriate. This has been a good review for me.

More on Essence

2011-08-10T21:48:00.000-07:00

[I have been working with the concept of essence, which encompasses all of the forms of energy that go into flying.]

Try not to take a side in this debate: does an airplane’s elevator control speed, or does it control height? Both sides have strong arguments, and neither side will ever be convinced by the other. The end of the argument is the passion of everyone involved.

Now sweep the question aside. Elevator has no effect on essence, at least for a while. By thinking – and thinking is part of essence – the question no longer matters, although the passion should still remain. Elevator can only change our finesse.

Sweep the question aside again. Why do we care about speed and height? We do not; these are surrogates for our true goal. We really aim to follow a certain path. Focus on your goal.

Forethought adds essence to our craft, both in the form of anticipation and in the form of fuel. We believe that we have the essence to complete the mission, and must manage its conversion from chemical or atmospheric energy to the kind of energy – height or speed – that we desire.
Too little dynamic energy – too little height, or too little speed, or too little of both – means taking some chemical or atmospheric energy from our stores. So open the throttle.

Some cars store energy from braking, but we have not figured out how to do this in airplanes. Both slowing down and going down destroy our essence. The rumble when the spoilers or landing gear extend carries essence from the airplane into the passenger’s brain, or even the pilot’s brain, and we have yet to think of a way to use that energy. “Welcome to Santa Monica,” the large sign reads, “Please fly quietly.” Preserve your essence: approach a little high. Now you have too much essence. So close the throttle.

Stick and Rudder

2011-08-09T10:52:00.000-07:00

[revised 9 August]

The F'n A A has been sitting on my application for a Special Issuance medical certificate for 53 days, so I'm restricted to Light Sport privileges (basically 2 seats, Day VFR, maximum weight 600kg). This is lots of fun, and it raises some interesting questions about flight training.

The Ercoupes I've been flying are intriguing airplanes. As I understand it, Fred Weick designed it to be safe, inexpensive, and fun. Most 'Coupes have aileron-rudder interconnects, eliminating the need for rudder pedals.

I used to think this was a travesty, and it makes me feel good about my skills to note that I'm better coordinated.

But now I'm beginning to think that the 'Coupe might be an ideal training airplane for the 21st century. One reason for this is the rise of the Light Sport category, which demands airplanes that are safe, inexpensive, and fun. There are some impressive LSA airplanes that look like fun: the ideal vehicle for, say, a skinny retired couple to explore the country. But these are expensive. Right now you can buy a flyable Ercoupe for $25,000, and maybe come February in a tough economy you will be able to find one for less. They need some TLC, but this can be fun, and costs a lot less than the $100,000+ new planes.

And, although I have mixed feelings about FAA certification (there is no reason for me to spend 7 summer weeks without a medical certificate), the Ercoupe is a CAA-certified airplane; the newer LSA airplanes are not certified at all, but are built to industry standards. Certification involves oversight by someone without a dog in the fight. I have seen corners cut in aviation.

But what about the flying part of the Ercoupe? I cannot look at you with a straight face and tell you that it is a stick-and-rudder airplane: it doesn't have rudder pedals! I've written before (and will again) about the importance of basic flying skill at all levels of aviation, especially slow flight and stalls. The 'Coupe won't stall!

By contrast, an Airbus 320 has little use for rudder pedals, and won't stall.

So what can one learn about flying? Well, try this: the other day I was out in an Ercoupe when the weather turned threatening and the wind picked up. As I approached the airport the wind sock showed light winds, but groundspeed on the upwind leg was low. I anticipated a fast downwind and wind shear on final. It felt early to turn base, but in fact I was high with a pretty good crab angle. Bump bump bump and now I was low with a pretty good crab angle, the other way. I touched down on the centerline in the crab, and the 'Coupe did its thing and we tracked straight until the runway exit.

Flying that pattern required a large number of transferable skills, skills that apply in every airplane from a single-seat glider to a 777. It did not require every single flying skill, but no maneuver does.

What about navigation? The Ercoupes I've seen have navigation equipment varying from a magnetic compass to a abasic IFR panel. The IFR panel is heavy, which is a problem: to quote Burt Rutan: before you install something in your airplane, hold it at arm's length and let go. If it falls to the ground it is too heavy. But a high-quality handheld GPS is neither heavy nor expensive. You may not use it to file IFR, but you can certainly use it to learn modern navigation. The right IFR GPS (or iPad app) can give a student NexRad radar, EGPWS, and airborne access to METARs and TAFs. There's no autopilot so it won't be tha hands-off flying that the Airbus driver enjoys, but there's still a lot of transferable skill to be learned.

The Ercoupe has wonderful visibility, making it easy (and fun!) to watch for traffic. That's a good habit.

So while the Ercoupe cannot make a complete pilot, no one airplane can, either. A wise instructor could produce a skilled professional pilot by supplementing the Ercoupe with a desktop Flight Training Device for learning instrument scan, and a light twin for learning to use the rudder. Both are important preparations for a flying career.

What do you think?

Essence

2011-08-03T17:16:00.000-07:00

Essence is a funny word. It is existence itself - esse means "to be" in Latin - and
touches the core of its object. Over time we have refined its usage, adding perfumes and foods - the essential oils. France goes further; there, airplanes (and cars, and trucks) are powered by essence.

Thus fuel becomes the essence of flying. Sailplane pilots roar in protest, but theirs is a narrow view. Fuel stores energy, but only of a particular kind, and when lacking we find a different source.

Energy - whether from fuel or the brain - keeps us aloft, moving forward, but not yet feeling good. The finishing touch - the finesse - completes the cycle.

Finesse is the end of flying, not the perfect landing but the very purpose. Finesse describes the wing, in a particular way. The usage has not taken off in English, but in French it describes the performance of the wing.

Energy and the wing: that's flying.

AF447, encore

2011-08-02T11:49:00.000-07:00

The Bureau d'&Enquêtes Accidentes has issued its very detailed report on AF447, in French. It is available here as a PDF.

Notable are excerpts from the Airbus 319/320 FCOM on stall recovery (p. 76): "PITCH ATTITUDE.....REDUCE", and Air France's A340 manual "ASSIETTE LONGITUDINALE.........REDUIT" (p. 64). There are exceptions when close to the ground, since reducing the pitch attitude is not an option.

Some of my comments here are still apt, so I will let the post stand, but I no longer believe that the crew did the right things. Sigh.

There is another lesson here: when the PIC left for his rest period, there was little or no discussion of the roles of the remaining pilots. Typically in a crew situation there is a pilot flying (PF) whose sole job is to keep the airplane on course and altitude, and a Pilot Not Flying (PNF) whose job is to run the radar, radios, navigation, etc. Many airline crews reiterate these roles every flight, and apparently Air France's training did not address the very common situation of the captain's rest period.

Everyone is in this situation during flight training. That's why your instructor is so insistent on the "I have the controls" "You have the controls" "I have the controls" dialog.

The CVR trasncript starts on p. 91 of the report. There are several "What's going on?" comments, and at least one "I don't have control of the airplane."

That's what people say when they stall.

Too Darn Hot

2011-07-30T15:39:00.001-07:00

Fire in flight! is one of the scariest things in aviation. An engine fire in a single-engine airplane turns you into a glider, since putting the fire out means shutting off the fuel. But an engine fire in a multi-engine airplane turns you into a brick. One of the axioms of multi-engine flying is that in case of wing fire you must put the airplane on the ground now, no matter where you are. There are tales of multis dropping like a rock on downwind.

I was taught that the reason for this was that the aluminum spar got "soft" when heated. This seemed plausible, so I believed it and passed it on. But that's superstition, which has not place in flight instruction.

So here is a graph from Dennis R. Jenkins's X_15: Extending the Frontiers of Flight, a NASA publication available free here.

The graph shows the strength response to temperature for several materials used in aviation: aluminum, magnesium, titanium, stainless steel, and Inconel X. Inconel X can handle amazing amounts of heat, which is why it was used in the X-15. (The Wikipedia article on Inconel seems pretty good.)
The vertical scale is Tensile Yield Stress, that is, how much stress does it take to make the material yield, "strength" in layman's terms. The horizontal scale is temperature.

The aluminum curve is pretty scary: at low temperatures the strength remains about constant, but at about 200F it starts to decline rapidly, and is halved by about 400F.

That's not very hot. As a cook, I regularly touch stuff nearly that hot (I often stir stuff with my hand rather than a spatula). French fries cook at 375F. Typical ITT temperature for a PT-6 engine is about 1350F, and piston EGTs are in the same ballpark.

Aluminum loses its strength at temperatures that are common in aviation!

So, if you are in an aluminum-sparred airplane and there is heat on the wing land right now. Don't try to reach the airport. Land right now on something that won't hurt anybody else.

A composite airplane like the Diamond DA-42, which I believe has a composite spar, might be different. If this is correct (don't take my advice unless you verify that the spar is composite) then the spar should be able to maintain its strength at much higher temperatures, and you have more options as to landing.

[revised 15 Aug 2011]

Atlantis

2011-07-22T08:57:00.000-07:00

[My hotel had connectivity issues, not my laptop. Phew!]

[This is a crude version; I'll clean it up and add pictures after I fix my laptop's connectivity issue.]

Sometime a couple of weeks ago I got a tweet announcing the STS135 Tweetup. STS135 was the NASA designator for the final mission, and a tweetup is a social networking phenomenon where people who know each other online through twitter gather for an event. I registered on the website. NASA took 150 of the rumored 5000 applicants to the launch.

Not me.

NASA opened a few slots for the landing, and this time I got picked! I hesitated a little: it would be expensive, tiring, and tough on my family to have me away again so soon. But I had to go!

So Tuesday I drove down to Salt Lake and flew to Florida. Wednesday I toured the Kennedy Space Center Visitor Complex; I'll write about that separately, except to mention the highlight, a Saturn V. Wednesday night I met two of the "tweeps", Marcus and Lisa, for dinner. There was something remarkable here that occured the whole time I was here in Florida: people from all walks of life drawn together by their fascination with spaceflight. We were like the people in Close Encounters of the Third Kind, drawn to Devil's Tower to see the landing. But this was for real!

Six of us met in front of the closed hotel lobby at 0245 and carpooled to Kennedy. We left early, expecting traffic, and arrived at our badging spot long before the NASA folks. The badging location was a small cinder-block building whose fixtures came from the era of Project Mercury. I asked around but nobody knew its history.

Our bus showed up and we boarded, every seat full. People were brisling with camera gear, but the NASA reps, Stephanie and Beth, suggested that we not take pictures because the whole thing would happen so fast. NASA has better photographers than me.

NASA provided an orbiter processing engineer named Chris (didn't catch his last name) who described the landing process, between-launch activities, plans for the decommissioned orbiters, and the like. I was familiar with a lot of this due to my voracious reading, but it was great to hear it from someone who had done it.

As you know, I have mixed feelings about simulations, but I can't access the shuttle or the Shuttle Training Aircraft, so I had been simulating the approach and landing using F-SIM, an iPad app that is reputed to be quite accurate. Atlantis would approach from the southwest and fly a Heading Alignment Cone to land on runway 15, and F-SIM allows a similar approach, complete with recordings of the dialog between the crew and Johnson Space Center ("Houston"). I know from watching the PLT camera view through the HUD during landings that the final portion is very realistic.

After Atlantis's deorbit burn the bus started taking us to the airfield. There was a little bit of a traffic jam but we got to the field in plenty of time. We were near midfield, and I had to make a quick choice, close or high? I chose close and stood at the rope.

Here's a google map screen capture, showing where we were on the field. Large screens were set up showing NASA-TV and we could hear the dialog between Atlantis and Houston. (This isn't special, I do this at home. But I wasn't at home, was I?)

It was before dawn, which was a good thing and a bad thing. Since Atlantis and the ISS were in the same orbit, it passed overhead about 9 minutes before the landing. I've watched the ISS dozens of times, but somehow this view was special. I was the first person in my part of the crowd to spot it, and everyone clapped.

The voice from Atlantis was calm. "It looks like we just passed over the Yucatan Peninsula," it said, "We wish more of you could see this."

"Atlantis, Houston," came the calm voice of the CapCom, "We show you crossing the West Coast of Florida."

Even astronauts get lost.

B-BOOM!

The double sonic boom announced that Atlantis had decelerated below Mach 1. It wasn't as loud as I had expected, but it was shaarper, more like a piar of cannon blasts. We all strained our eyes to see it passing overhead in the night sky.

This is where the sim came into play. "Atlantis, Houston, you're on at the 180." Just like the simulator app! This meant that Atlantis was on downwind, at proper altitude and airspeed, a few mile north of KTTS. I knew where to look. Nothing.

"Atlantis, Houston, you are on at the 90." OK, they're descending through 16,000. I know what they see.

"Field in sight, Houston."

What? What? The crowd around me didn't get this, and I explained.

Now they were at about 13,000 and turning final. The HUD was showing them an extended centerline, and they were steering off PAPIs calibrated to their steep glideslope.

We saw nothing. Everyone seemed to lean toward the final approach course. It was like the final minute of a tied Stanley Cup final.

"Pre-flare." OK, they're passing 2000 AGL.

Still nothing.

Suddenly a shadow passed through the floodlights illuminating the runway. I shouted something incomprehensible, and felt the electricity passing through the crowd.

"Main gear touchdown."

Still nothing in sight! The crowd was cheering.

The drag chute appeared above the bushes, and all of a sudden THERE IT WAS, still moving fast. As it passed out of sight the drag chute stayed attached, and by the sim that means that they were still moving at more than 100 knots.

This felt familiar, but I can't explain why. It reminded me of a very low approach (1/4 mile) I'd flown in a King Air, which wasn't scary until I saw the 1000 foot markers at the far end. Gotta stop!

It's a cliché, but the sight was awe-inspiring.

We reluctantly drifted back onto the bus as dawn broke, people stopping on the stair for a last look at the tower and the airfield. The orbiter was out of sight. We rode back to our cars. Everyone was bittersweet: we had seen an amazing thing, but a magical era had ended on our watch. We lingered in the parking lot, took pictures of our new friends, and headed back to the hotel to try to get some sleep.

I don't know about the others, but I couldn't sleep.

But the shuttles will.

Grounded

2011-07-13T20:31:00.000-07:00

I haven't heard anything but "in line for review" from the FAA medical folks, but that doesn't end all aviation activity.

Saturday I helped the nice people from EAA chapter 1114 (Apex, NC) with a Young Eagles rally at Siler City, NC. The kids got 59 rides. I was ground crew, of course, but I couldn't help but wish that Claude B. needed a break flying the beautiful Ercoupe his grandfather bought new. Man, does he have stamina!

When I say 'grounded' I mean it in the colloquial sense of "at peace with the world and making a positive contribution."

The thing is, even without word from the FAA, I still have Sport Pilot privileges. My medical expired, it was not revoked; nor was there cause to revoke it. So I could have done it!

And tomorrow I will. My friend Richard owes me some time in his 'Coupe. Being a Sport Pilot really is a privilege.

Crepuscule with Nellie

2011-07-10T19:47:00.000-07:00

Before we had METARs, we had SAs. If I remember correctly, SA stood for Sequence Advisory; by the same token, a PIREP was a UA, or Unsolicited Advisory. SAs appeared on yellow paper on a teletype machine at the Flight Service Station (that's an honest teletype, not the new-fangled KSR-33). They came up in order: Pittsburgh, Harrisburg, Wilkes-Barre, Philadelphia, and so on; you could watch a cold front move across the country.

When we switched to METARs the RMK field became more formalized, and human weather observers lost the ability to put CREPUSCULAR RAYS in the comment section. Presumably the machines don't notice.

Crepuscule means twilight. I didn't learn the word "crepuscule" from a sequence report; it comes from this song by Thelonius Monk. Here Monk and John Coltrane perform Crepuscule with Nellie at Carnegie Hall. The song combines dissonance with poignancy.

My made-up explanation for crepuscular rays is highly humid air, which glows red at crepuscule, and towering cumulus to the west blocking some of the sun's rays. So the rays are actually the absence of the Sun's rays.

Seeing that remark in the SA reminded me of every evening I ever spent outdoors in the South or Plains. Crepuscular rays meant spitting watermelon seeds, fireflies, an AM radio in the distance tuned to a minor league baseball game, and maybe holding hands with a new girl.

And besides inducing nostalgia for my Taylorcraft, crepuscular rays meant something about the weather. Towering cumulus to the West in the mid-latitudes of the Northern hemisphere usually come your way, and seeing them at sunset, when things should be calming down for the day, means that those CU have lots of energy. Crepuscular rays are a poison flower, pretty to look at but...

Arc en Ciel

2011-07-02T17:39:00.000-07:00

[I prefer writing about flying to writing about me, but this is an unusual juncture so please indulge me.]

For some reason the date was memorable: May 5, 1992. My third class medical certificate was expiring, and that day I got a second class certificate. The way things work in the USA, flight privileges are tied to the medical. For commercial privileges, one needs a second class certificate; for Airline Transport privileges, one needs a first class.

I got my commercial certificate in an old Cessna 210, the kind with struts and a hydraulic system so ancient that it took significant strength to position the valves to raise or lower the landing gear. An ag plane cut me off in the pattern and the examiner seemed to think that the required emergency was covered. I was a Commercial pilot.

I worked my way up, earning a bunch of certificates: multi, CFI, CFII, MEI, Commercial glider, CFI-G, and, most important of all, ATP (which took two tries, the only one that did so). For that I needed a first class medical (technically a third class will do to take the test, but you need a first class to use it), and after my double bypass in 1998 I kept my first class medical certificate, hoping for a jet job (jet captains under 14CFR135 must have an ATP, hence need a first class medical). Since I wasn't using it I let it lapse to a second class for the second six months, but during that first six months I endorsed a lot of logbooks with "ATP" rather than "CFI", instruction in commercial operations being an ATP privilege.

I flew freight, fires, and frightened patients all over the West. There is no possible universe in which a part-time pilot who is also a mathematics professor with heart disease can fly a King Air, but I got three years in King Air 200s anyway.

Two more cardiac interventions cost me the King Air, and I gave up on the jet idea and, as a consequence, on the first class medical. But I kept the second class and my commercial privileges. ATP was now a diploma on my wall and an attitude toward flying, but not something I used.

A year ago, after the incident described here, the FAA's annual letter describing what it would take to renew my second class medical became draconian: they were demanding much more testing, testing that neither my insurance company nor wallet could justify. AMEs tell me this level of testing won't be required for a third class medical.

My second class medical certificate expired June 30, and I have informed the FAA that I will not seek another (see above). The FAA is concerned about my heart, but without Rheumatoid Arthritis I would have the energy to make enough money to pay for the heart testing. And now there's evidence connecting RA and heart disease. Since my heart disease is unusual (no risk factors, no lifestyle changes, no symptoms: the only effect is that every now and then they take all of my money), it may have been RA all along.

In other words, I am a Private Pilot now. (I'm still a CFI; that's teaching, not flying.) I even changed my blog profile to say former professional pilot.

Make no mistake about it: I am proud of my PPL. In the next few months I'll write about the joys and adventures being a PPL can bring. I'm hoping for at least one long trip, and maybe a seaplane rating.

And I still intend to fly like an ATP; I have some things to say about that, too.

ps I have started a Google AdSense account, which is supposed to target ads based on content. I hope you don't mind; it seems unobtrusive to me, and it would really be nice to get a little compensation for all of this writing. I noticed in looking up the post on my most recent stent that AdSense came up with ads for heart surgeons. Now that's targetted!

Space Weather

2011-06-19T21:49:00.000-07:00

It was March 13, 1989, in Utica, NY. My apartment was rather spare but it had a nice view North across the Mohawk Valley. There was plenty of privacy - the nearest prying eyes would have been 15 miles away - so I often left the shades up to sleep.

That night I had to close the shades. My bedroom was fully lit, but not with a steady glow. The greenish light danced and leapt around the room; it might have kept me up all night. Looking out the window revealed the most intense aurora borealis I have ever seen.

I had it lucky. The province of Québec lost all electrical power that night. The solar storm that caused the aurora also disabled the power grid.

That was my introduction to space weather, the study of the bands of charged particles that surround the Earth (the ionosphere), which are just as intricate and fascinating as the atmosphere. Its nature wasn't really understood until 1958 when the Explorer satellites made in situ observations. Prior to that, we knew that something caused the auroras at the poles. Admiral Byrd in his book Alone talked about measuring the aurora australis by triangulating. He spent the austral winter alone in a cabin (where he nearly died from CO poisoning), making observations, which were later compared with observations made at Little America, his Antarctic base.

A recent article in the New York Times was surprisingly shallow, except in making pilots look bad. To quote from the article:

"...a space weather forecaster we know at the National Oceanic and Atmospheric Administration often tells a story of a conversation he had with a pilot:

"Pilot: 'What do you do for a living?'

"Forecaster: 'I forecast space weather.'

"Pilot: 'Really? What’s that?'”

So, why should pilots care about space weather? Start with the South Atlantic Anomaly (SAA, a permanent feature). NASA pays close attention to the SAA, to the point that it is prominently displayed on the screens at Mission Control. For reasons that I do not quite understand, the Van Allen radiation belts are lower in this region, exposing orbiting spacecraft (and their occupants) to more radiation. This disrupts communications; actually, it disrupts anything electrical. (What I don't understand is, given the Earth's rotation, why this does not occur at every longitude.)

Wish as we might, most of us aren't astronauts. But every time you press DIRECT on a GPS you are a rocket scientist. Well, maybe not you, but there are bunch of rocket scientists in the picture.

The problem is that the GPS signals have to go through the ionosphere, which slows them down. Remember that GPS receivers calculate a pseudorange to each satellite, putting you on a gigantic sphere, and the intersection of four of these spheres defines your position in space. Then, using the WGS-84 model of the Earth (or one of its refinements), the receiver calculates your latitude and longitude.

The GPS position calculation assumes that the signals travel at the speed of light, and, knowing the position of the satellites from the ephemeris, determines which sphere your on. Originally, the system used two ionospheric corrections each day, but that was too crude. Here's the space weather: ionospheric storms that can really slow the GPS signal can last as little as fifteen minutes! So a twice-daily correction didn't cut it.

If your receiver can use two frequencies it can estimate the ionospheric delay, but older civil receivers only had access to one frequency. (Many of these are still in use.) So, again we were out of luck.

A lot of smart people put a lot of work into figuring out how to monitor this and other effects on the GPS "Signal In Space", and the final result is WAAS, the Wide Area Augmentation System. WAAS monitors the GPS signals at many locations, calculates corrections, and broadcasts them from a geosynchronous satellite. Most new GPS receivers are WAAS capable, and this leads to unbelievable accuracy and reliability.

We are approaching the peak of the sunspot cycle, although the Sun has been uncharacteristically quiet the past couple of years. More sunspots means more interactions with the ionosphere and more chances for a massive GPS outage.

Check out Spaceweather.com if you'd like to learn more.

AF447, again

2011-06-13T19:34:00.000-07:00

The June 6, 2011 issue of Aviation Week and Space Technology contains more information about AF447 than was available in my last post. There, I concluded that the crew had acted correctly, but the airplane didn't. Based on what I read today, I was wrong. The pilot flying continued the nose-up stick inputs for quite some time. That's not the right thing to do.

We forget that accidental stall is insidious, like a lot of other problems in aviation. The other day I was playing with a Flight Training Device, evaluating it for use in IFR training and Instrument Proficiency Checks. We were fooling around telling jokes, and I wasn't looking at the instruments. With the FTD there are no cues like slipstream to let you know that the speed is too low. When I looked back at the instruments the airspeed was low and and the nose was high. STALL! I jammed the yoke forward, but the stall still broke, hard, and I started to try to use rudder to keep the wings level.

There wasn't enough room to recover. Stall, spin, crash, burn, die.

My Little Runaway

2011-05-30T12:48:00.000-07:00

Since I am a college professor, I say "It's more complicated than it appears" and "Wait until we have all the facts before we draw a conclusion" often. That's why I haven't said anything about AF447, except for one tweet about this post when it became clear that the aircraft had stalled. I felt that I was in no position to judge the flight crew or its actions. "It's more complicated than it appears," I thought, "Wait until we have all the facts."

I'm glad I waited. An article today in the German Der Spiegel raises some questions about the Airbus's automated flight control system. It appears that both of the Airbus's side sticks were commanding "nose down," as expected. But the nose didn't come down, and the horizontal stabilizer moved in the nose up direction. The captain evidently took a seat with a comment from one of the co-pilots like "Here, you try it!"

They did the right thing.

The airplane didn't.

I am hesitant to draw a conclusion about French aircraft and stabilizer trim, but it is tempting to see a relationship between the recent grounding of the Falcon 7X fleet and this report. A Falcon 7X had a pitch trim runaway, so the fleet was grounded. Good move.

Those of us who fly smaller airplanes might wonder why the flight controls didn't overpower the stabilizer trim. In some heavier airplanes (starting with the Lear 25), the stabilizer trim is much more powerful than the flight controls, especially in the situation where the whole stabilizer moves, rather than a tab (tabs are bad because in some situations at high airspeed they can cause control reversal). United lost a DC-8 in 1983 due to a mis-set stabilizer trim (NTSB data here). Alaska lost an MD-80 to a stabilizer trim problem. Next time you're around airliners look at the stabilizer: there are usually marks on the tail showing the maximum and minimum stabilizer position, so it can be verified during the walk-around.

I've had two pitch trim problems, neither one of which caused a crash. The first was in my Taylorcraft: I was a little too enthusiastic with the trim crank and pulled the cable off the pulley, leading to a full nose-up trim condition. The T-craft uses a single trim tab on the left elevator, and while it was annoying I had no trouble pushing the nose down and completing the pattern. After that I learned my lesson: I trimmed slowly (which is the right way), and told riders "That's the trim crank; don't touch it!" No problem.

The other was in a Seneca. The electric pitch trim wouldn't respond. I played with it for a while and, consistent with my philosophy that circuit breakers are for pulling but not for pushing, I used manual trim for the rest of the flight. Good thing: there was a short in the system, and there were sparks behind the panel.

I've also had an autopilot runaway, in a Cessna 414A. Wait, I've had two autopilot runaways, but the second was caused by a pilot with an unpleasant personality who wanted to see how I'd react. (He didn't last long with the company.) The real one was on the final leg of an air ambulance flight. It was about 0400 and the final leg was less than 50NM in night VFR conditions. But it was 0400 and I was tired. I engaged the autopilot and the nose shot up into the darkness. Huh? Whoa! Phew!. I hit the autopilot disconnect and lowered the nose.

But it was 0400, so I engaged the autopilot again. Huh? Whoa! I disconnected it and hand-flew the rest of the way home.

Phew!

Time Travel

2011-05-16T19:22:00.000-07:00

I was talking with a prospective instrument student this morning who, like most, was concerned about approaches. His home airport has three approaches, one VOR-DME and two RNAV, and I know that his airplane isn't equipped for the RNAV approaches. But that's irrelevant: approaches are the last thing he needs to worry about now.

Teaching instrument scan is one of the most challenging assignments I have ever faced. I've tried all sorts of things and maybe there are a few I haven't tried. The diagrams in the FAA Instrument Flying Handbook are of some use, but they can't duplicate the dynamic nature of the situation. One instructor impersonates a metronome, and the student is supposed to look at a different instrument at each tick. Another takes a pencil and taps each instrument in turn, saying "Look here!" "Look here!" "Look here!" (This one works pretty well, actually.)

When I was at my sharpest as an instrument pilot (alas, that was a while ago) I noticed something strange. The perception/reaction sequence seemed to get reversed. Typically, you would expect that first a needle would move, and then you would perceive the movement during your next pass around the panel, right? But when I was at my sharpest I found that I would look at an instrument and then it would move. (This isn't just me; I've heard this from others.) I used to tell my students that that was the goal for being instrument sharp.

I couldn't explain this. It couldn't be that my body sensed any motion, because I had pretty rigorously trained myself to tune out somatic stimuli. How did I know that the needle would move just before it did?

I think I have an answer, and it is going to sound quite strange and mystical, but I assure you that it is pretty solid science. You can read more in the April 25, 2011 issue of The New Yorker; the article is by staff writer Burkhard Bilger.

This explanation depends on two widely-recognized principles: first, the brain takes in more information than our conscious minds can process, so it selects what we attend to; and, second, there is some delay between an event in the world at large and our perception of that event. David Eagleman, a neuroscientist at Baylor University, studies the nature of consciousness, and has spent a lot of time trying to measure the interval between event and consciousness as well as what happens during that interval. This isn't filling cranial cavities with beans: he is using functional MRI to map the regions of the brain that become active in response to certain stimuli.

The short version is that the brain constructs a story around all of the data the senses bring in and merges all of this sensation data into the story. So here's what happens in instrument flying. Say that the airspeed starts to rise but you are conscious of gazing at the altimeter. Your brain perceives the change, and you travel back in time to the instant before the change occured, directing your consciousness to the airspeed indicator. Well, no, you don't travel back in time, but you don't travel ahead in time as quickly as you usually expect. A good neuroscientist like Eagleman could set up an experiment to see if the pilot's eye really moves to the airspeed indicator, or whether the change of conscious focus happens internally.

Instrument training teaches the brain that the airspeed needle movement is important and requires a change of focus, while the corresponding movement of the second hand on the panel clock is of no consequence and therefore should not be brought to attention. When you get it, it doesn't matter which instrument you focus on. Your brain perceives them all, and will let you know when one of them does something important.

If this is correct (and even I have my doubts) then it doesn't matter whether the instructor uses a metronome or a pen or a series of strings going from instrument to instrument that looks like some impossible cat's cradle position. What matters is that the instructor makes the brain attend to the instruments and that the student spends enough time practicing to lay down the neural pathways.

Our society likes speed, and you can certainly find accelerated this and superfast that. I've always had my doubts about accelerated training, though. I think it produces a different kind of knowledge than the slower variety produces. I'm not saying that the knowledge is inferior; in fact, it can be quite useful. But one has to understand that some kinds of knowledge just take time. National Football League coaches say that it takes 20 to 25 games before a new quarterback has the game "slow down" enough in order to make him effective; it's the same kind of thing.

My prospective student told me that he would like to fly every other week for some reason I couldn't quite follow. No matter.

"You'll never finish the rating at that pace."

Learning fades unless it is repeated, and two weeks between practice sessions is too long for an adult. The neural pathways would fade rather than be reinforced.

And every flight instructor knows this. Students who fly infrequently, at every level, drop out. You can speed things up a little (4 or even 5 flights a week), but not too much, and you just can't slow things down.

Even if you can travel backward in time.

Sled Ride

2011-05-11T08:51:00.000-07:00

It's happened to every glider pilot: the day looks promising, but the tow is eerily smooth, and you can't find any lift even after trying every house thermal and other trick you know. You enter the pattern and land. "I got shot down," you say, or "I needed a relight." (I like the relight metaphor better because of its focus on energy.) Or "It was a sled ride."

This week's Aviation Week and Space Technology mentions the ultimate sled ride after Virgin Galactic's first test of the feathering mechanism for SpaceShip2, their commercial space tourism craft. They took a high tow, to 51,500' MSL. Then they pulled on the spoilers (the feather mechanism) and descended at 15,500 feet/min to 33,500' MSL. They didn't even look for lift: they just entered the pattern and landed. Flight time? 11 minutes, 5 seconds.

Now that's a sled ride.

A little closer to home, our glider club met last night and decided to look for a new trainer since our Blanik L-13 is grounded (along with the rest of the Blanik L-13's in the universe, including the one hanging form the terminal ceiling in Santiago, Chile). Sled rides are an important part of training, especially for newcomers learning to land. I hope we can get some soon.

Rescue Me

2011-05-02T09:54:00.000-07:00

I have long been an advocate of VFR flight plans (see this post) but a recent Civil Air Patrol presentation to my EAA chapter reinforces the message. Thanks to Bobby Picker for sending me the data to share.

First, as we pilots know, a VFR flight plan has nothing to do with securing government permission to fly a specific route. It used to be in Australia that flying without a flight plan was "NoSAR," for "Search and Rescue." And search and rescue is the purpose. So let's refer to our flying as SAR and NoSAR.

According to the CAP, 60% of crash survivors are injured. The injuries are severe. They say that 81% will die if not located within 24 hours, and 94% will die if not located within 48 hours. Being uninjured doesn't improve your odds much: 50% die within 72 hours.

Of course it won't happen to you, which is what my late friend Blake (thousands of hours, flown everything) probably thought last month. Yes, it can happen to you.

So how long does it take to get rescued? That's where flying SAR comes into play. Here's the data on how long it takes to start the rescue process:

SAR status

time to AFRCC notification		time to rescue
15.6 hours	if no flight plan filed	62.6 hours
3.9 hours	if a VFR flight plan filed	18.2 hours
1.1 hours	if an IFR flight plan filed	11.5 hours

Rescuers talk about the Golden Hour: quick rescue prevents death. NoSAR flying leaves you nowhere close. And even the best rescue - from an IFR flight plan - makes some survival preparation look attractive.

The CAP recommends that you should always file IFR, but in my part of the world that's not always an option. Last week I took a pilot friend visiting from back east to Afton, WY (KAFO) in the club Archer. The direct route is already problematical, but the airways route is twice as long. Sorry, not for a fun flight. A big chunk of the route has a 15,000' MSL MEA, pushing the Archer's service ceiling. And I'm not equipped for the approach. Filing IFR is not an option.

But neither is flying NoSAR, and my friend was pleased to see me file a VFR flight plan.

I tell everyone who might listen that opening a VFR flight plan is easy, and that every VFR flight allows for 2+n PIREPs, where n is the length of the flight in hours: one on departure conditions when you open, one on arrival conditions when you close, and one when you do your hourly position report. Many people no longer need to talk to FSS to get weather updates, but that position report could make big difference in your rescue.

in this case LockMart couldn't follow my PIREP on the departure conditions ("continuous light turbulence SFC-070, type is P28A, unlimited visibility"), and it took almost 5 minutes to open the flight plan.

But still I'm glad I did.

Huh? Whoa! Phew!

2011-04-11T19:43:00.000-07:00

Dave English at hikoudo.com points out this article by Thomas Anthony on the Flight Safety Foundation website. These three words, spoken almost involuntarily, tell you that a threat is present so you'd better sit up and fly right. The article is well worth reading.

I said both "Whoa!" and "Phew!" yesterday. A friend keeps telling me that I can fly his Ercoupe if I buy the gas. I finally did so yesterday. A solo flight from an uncontrolled field is some of the best "alone time" a person can have.

Not knowing where to fly, I headed home. Maybe I'd see the cat in the driveway? I live on the downdraft side of a steep hill so circling the house takes a little thought. As I headed away from the hill I took a picture.

Whoa! When I looked up there was a gull at 11:30 and 30 feet, with several others nearby. The 'Coupe has big ailerons and short wings so my quick right bank averted the collision. If I was one of those biologists who recognizes individual birds by their markings I would have known this one's name.

Phew!

Or should I say Dummy! All week I had been watching the gull superhighway that goes from the dump south of town to the lake north of town. I had guessed that they were at about 6,000 MSL.

And where was I? 6,000 MSL!

Right intention. Right effort. Right mindfulness. Right concentration. I missed four branches of Buddhism's Eightfold Path.

At least I had right action.

Personal Minimums

2011-04-09T21:39:00.000-07:00

People have thrown the phrase "personal minimums" around for a long time, but I think there's been something missing from the discussion. And while I am writing this for Sport Pilots, it really applies to every pilot.

The safety gurus try to make the "personal minimum" decision sound easy, but I've never found it that clear cut. A few years ago I was flying some very nicely equipped King Airs, took annual simulator training, and had to take a semi-annual instrument check. If it was legal I could handle it. Well, at least "legal" in the King Air. One winter afternoon I took off in my Taylorcraft and headed west across the desert. It was VFR but the white sky and snowy ground meant that there was no visible horizon. The T-Cart had a venturi driven turn needle that seemed to work best on hot days, so my instrument proficiency was of absolutely no use. I turned around and landed.

In other words, a pilot who was IFR proficient below 1/2 mile visibility cancelled a flight because it wasn't good enough VFR. It takes two to tango.

The FARs contain a huge loophole for charter pilots (14CFR135) that I flew through regularly. To launch on a charter flight you could use any combination of reports and forecasts to make sure that the weather would be legal when you arrived. So a forecast for bad weather that was worse than the reported weather meant I could go. Incredibly poor reported weather could be ignored if the forecast said it might improve, even if every ounce of common sense indicated that the forecast was wrong.

FAR 61.315 spells out sport pilot privileges and limitations. These seem pretty clear-cut: no night flight, no flight above 10,000 feet MSL except within 2,000 feet of the surface, no flight with less than 3 miles flight or surface visibility. The last one means no Special VFR, and no taking "advantage" of the reduced visibility required by FAR91.155 for Day VFR in Class G airspace. (This so-called advantage is the classic example of something that is legal but not safe.)

Furthermore, a Sport Pilot must maintain ground contact. A Private Pilot may legally fly above an overcast, and sometimes this can be safe. Sometimes. But a Sport Pilot may never do this.

The reason Sport Pilots have these limitations is that they are not required to have instrument training, while Private Pilots must have three hours of "hood" time. It always seems a shame to put someone under the hood on a pretty day, but still I make my Private Pilot students fly to the practice area and back under the hood, and they also spend some cross-country time unable to watch our lovely scenery go by.

Even if you are a private pilot, you are limited to these conditions if you have limited yourself to Sport Pilot privileges by using your driver's license as your medical.

So what's the problem?

The problem is that there's no mention of the forecasts.

I've visited a few EAA chapters recently and I have heard a lot of talk about Oshkosh. Some of it has come from me, because the last time I made it to Oshkosh was before my teenagers were born, and it's long past time to go again. As I think fondly of the great people I met there and the wonderful things I saw and learned, I can't help but recall that every time I have gone to Oshkosh it's been IFR. I think one time the visibility was 2 miles, but never 3 while I was flying. If you get a standard briefing then you'll get a NOTAM for IFR conditions. Pay attention.

Enroute it may not have been IFR but VFR flight was a lot more comfortable above the convective layer. If there are scattered cumulus then it's OK for a Sport Pilot to be "on top", but when the clouds are broken being on top is questionable and when the clouds are overcast it's illegal. The Area Forecast should give you some information about the cloud tops.

Any trip east from my home airport involves lots of mountain flying. There is a route from home to Oshkosh that stays below 10,000 feet MSL, but there are lots of wind conditions that make 2,000 feet above the ground too low for my taste: think about the Steve Fossett accident. And more than once I've found the valley I intended to fly through blocked by rain or snow. "Sometimes you just have to fly toward the blue sky," but what if that means climbing above 10,000 MSL? Can your airplane do it? Can you do it, legally?

So you really have to pay attention when you see those little hints like VCSH in the TAF. (That means showers in the vicinity.)

The missing piece of the personal minimum decision comes from understanding the forecasts. TV weather is fine for a local flight, but when you set off on that looooong cross-country you really need to understand the forecasts.

Your ability to obtain, read, and interpret a forecast becomes part of your "personal minimums." If you can't understand the forecast then you shouldn't go.

Any pilot who intends to fly any serious cross-country really needs to practice with TAFs and Area Forecasts

Stalls

2011-03-19T16:20:00.000-07:00

Stalls? Yes, stalls. An article in the current issue of Aviation Week and Space Technology describes how loss of control has replaces controlled flight into terrain as the number one cause of accidents, with details on several accidents in which stalls were a factor: the Colgan Air Q400 at Buffalo, NY, in 2009, a West Caribbean Airlines MD-82 in Venezuala, and a Turkish Airlines Boeing 737-800 in Amsterdam.

How could a professional pilot stall an airplane into the ground? There are many contributing factors, but I think one of the must be the way that our current training materials make the meaning of "stall" obscure. To quote the Airplane Flying Handbook [FAA-H-8083-3a], "A stall occurs when the smooth airflow over the airplane’s wing is disrupted, and the lift degenerates rapidly."

A young instructor recited a similar definition to me the other day, and I compared it to hay after the horse has eaten it. The reason is that while this definition describes the aerodynamics effectively, it doesn't tell you how to recover from a stall. How does a pilot smooth the airflow? By polishing it clean? How can you reattach the boundary layer? Is that what duct tape is for?

In the old days (and I'm not that old) we used to teach that a stall meant too high an angle of attack. That definition tells you how to recover! "Stalled," I say, pulling an invisible yoke into my gut. "Unstalled," I say, pushing an invisible stick to the invisible panel. "Stalled." "Unstalled." "Stalled." "Unstalled." Until the point is made.

The FAA also says "the application of more power, if available, is an integral part of the stall recovery." That's wrong; ask any of my glider students! You add power to climb away, not to recover.

So I have taken pen to paper again (metaphorically) and written another cranky letter to the editor of Aviation Week. (AOPA Pilot didn't publish this one, by the way, although I got a nice note from Bruce Landsberg about it). Here's what I wrote, working to fit their 200 word limit:

The increase in loss-of-control accidents is partly explained by the confusing way we teach stalls. Today’s instructors talk about stalling as a boundary layer effect, which does not offer any insight into recovery. We used to teach that a stall was excess angle of attack, which also describes the recovery procedure: Reduce the angle of attack. A pilot who understands stalls this way is unlikely to descend to the ground with the
yoke fully aft.

Pilots are also taught that power is part of stall recovery, although my glider students do not have that option. The purpose of power is to climb away. The net altitude loss from starting recovery before adding power is minimal, and the risk of loss of control is reduced. This recovery sequence is most important in an airplane like the Bombardier Q400, which risks both spin entry (due to the large left-turning tendency from two propellers) and Vmc loss of control (in the event of an engine failure). (Granted, if engines have long spool-up times it is prudent to start that process as soon as possible.)

Advanced training as offered by the major simulator centers offers few opportunities to correct this basic misconception, leading to the tragic results you described.

Flying with Finesse

2011-03-17T20:10:00.000-07:00

One of my students suggested a book I'd never read, Henk Tennekes The Simple Science of Flight (MIT Press, 1996). My heart sank a little when he lent me his copy. "This is a book I'd like to write," I sighed.

Tennekes has the audacity to apply the basics of Aeronautical Engineering to all flying creatures, "from insects to jumbo jets." The discussion is clear and gentle. He puts all of the material together -- and I mean all of the material. For example, study The Great Gliding Diagram, which shows the polar curves for 10 flying objects: the cabbage white, the Gossamer Albatross, a typical sailplane, a swift (the bird, not the Globe-Temco beauty), a real albatross, a budgerigar, an ultralight, the Fokker Friendship, a pheasant, and the Boeing 747. You can compare the performance requirements directly, and there are many interesting consequences about wing loading, wing shape, power requirements, and the like.

Apparently the French call "L/D," the ratio of lift to drag, the finesse. I will now use this term forever. By the way, we owe the concept of the polar graph that shows vertical speed versus horizontal speed to another French engineer, Gustave Eiffel, of "Tour d'Eiffel" fame.

My current aeronautical thinking is that everything depends on two parameters: energy, which I wrote about in this post, and L/D, which I wrote about here. Those posts are just the beginning, of course, hence my idea to write a book explaining every maneuver and performance calculation in terms of these two.

But it would be a nerdy book, full of equations and tables. Tennekes does not shy away from equations (Stephen Hawking claims that every equation reduces the sales of a book by a factor of two), but his gentle prose and simple ink drawings really evoke the beauty of these simple ideas. Perhaps with Tennekes's inspiration I can write something with a little more finesse, too.

Pure Love

2011-02-26T20:16:00.000-08:00

While I do not miss the 4am wakeups to haul some banker out of Jackson Hole to foreclose on a property across the state, I do miss the air ambulance flying. One of my flight nurse friends posted this on his facebook page today:

"If you were to ask me what was the most memorable experience I've had as a nurse I would say it was the day I went toe to toe with a neonate a few hours old, just as we climbed out of the clouds... Pure love."

There was another kind of pure love on these flights. We lost some patients. Giving everything you have while a stranger dies is as pure as it gets.

Boy - Rock - Water

2011-02-24T09:38:00.000-08:00

It was payday at the airport and another typical day
at the university. Which one of those sounds more attractive? So after finishing my class prep I headed out to the airport.

The combination "boy - rock -water" has an inevitable outcome, as does the combination "boy - money - airplane". What better use for my Flight Instructor pay than to spend a few minutes off the planet? What reasonable mission might I accomplish?

Ah! Here's an engineering question: how far above the house does our wireless router's signal travel? (Our home network is JETNet: my family members' initials are J, E, T, and N.) Would I see "JETNet" on my network list as I flew over?

That sounds like a reasonable question; so reasonable that, as an Affiliate Professor in Computer Science, it should be a tax-deductible flight.

I couldn't find the network, but I don't think I'll write a paper for Nature about it, either.

For many of us, flying "after work" means flying during the freight rush. There were 6 IFR departures and 3 IFR arrivals during my 30 minute flight, not including me, and Rob was busy in the tower. I monitored the tower during my experiment, mostly for amusement. Headed back, I could see the lights of a Gulfstream 200 outbound on the ILS and put my nose on them, which amounted to lag pursuit given the speed difference. Spacing was good, but the tower asked me to do a 360 on 4-mile final to let a SkyWest Brasilia depart. I complied, but was disappointed that they did not say "Thank You."

Even though it was quite dark, it was within an hour of sunset, so I got no night landings. This is a little ironic since it was much darker than the other night when I flew the Cherokee Six for night currency.

This sounds selfish, but I am disappointed to see my piloting skills continue to deteriorate. Not to the dangerous level, but I do find myself forgetting little things that used to happen automatically, the same things I observe in pilots who fly about as much as I do these days. Some things continue to be easy, so I think I have other people fooled, but in my heart I know that there is room for improvement.

Which means I better fly more!

Forgotten Classic

2011-02-18T23:03:00.000-08:00

When I first fell in love with flying I had already been in love with books, and I spent (and spend) countless hours chasing down used and rare books. When I started scrutinizing the aviation sections there seemed to be hundreds of copies of Guy Murchie's Song of the Sky clogging every used bookshop in the land. There were so many that I paid no attention, although I had fanned through it and noted that author's hand-made etchings. But, money and time being what they are, other books seemed more pressing. "I can get that one anytime," I thought.

Of course I was wrong; after a few years Song of the Sky had disappeared. I forgot about it until my wife returned from a recent business trip with a present.

Murchie covers some of the territory familiar from Ernest K. Gann's immortal classic Fate is the Hunter, but there is a different feel. Gann's prose is spare and beyond analysis. I pick it up and start to read a passage to see what makes it so good, but I get sucked into the story and forget all about Gann's prose.

But Murchie is more Byron than Hemingway, and he is not afraid to follow an idea where ever it may lead. All I know of his other writings is what I read in Wikipedia, but it appears that his interests were remarkably broad.

Which is as it should be. As much as I love flying, I'm always a little concerned when I run across someone with no other interest. How can this be? Flying is intertwined with geometry, art, leadership, mechanics, computing, law, the atmosphere, the stars, rocket science, and, as we all know from slipping these surly bonds of earth, poetry. To be interested in flying is to be interested in everything.

It's going to be a good read.

Tough Day at Jackson Hole

2011-02-08T12:41:00.000-08:00

It looks like yesterday was a tough day in Jackson Hole, Wyoming (KJAC). I looked Flight Aware to see how a friend was doing; apparently he forgot about the strong west wind and flew through the localizer after the procedure turn:

He was better off than American 2253, a Boeing 757. It looks like they held at Dunoir VOR for quite a while before diverting to Salt Lake City. I've done about that many turns in that hold waiting for ILS minimums.

After cooling their heels in Salt Lake for a while, American 2253 tried again. This time, it looks like they went to Dunoir for the ILS-19 before changing their minds and opting for the VOR-DME 1 approach. (You can tell which approach because it looks like they flew the 16DME arc.)

If the weather was decent (which might have been the case even though the airport was showing 3 miles visibility in snow) the passengers got a nice tour of the Gros Ventre and Wind River ranges.

When I flew King Airs I went to KJAC a lot. I often touched down as the tower opened (0700LT). This meant that I had been in the air at 0620 or so, so I had been at my home airport at 0515, which means I left home at 0445, which meant that I had to get up at 0400.

I don't miss the 0400 wakeups...

Fogged Out

2011-02-06T22:23:00.000-08:00

I had to cancel another trip. I shouldn't be surprised: a simple single in the heart of the Rockies in the middle of winter isn't much airplane. And my ego forces me to broadcast "I could do it, but the airplane wasn't capable." I've done the mountain strips on moonless nights, in turbocharged or turboprop twins. I've done the "moderate" ice that proved severe (freight dogs "protect" each other by reporting moderating, since many carriers have Operations Specifications, and many airplanes have limitations, about severe ice). Nope, I can do it, but the airplane can't.

In the Archer, I can do an ILS to 100'. Wait, isn't Decision Height usually 200'? Yes, but by 14CFR91.175, you can descend to 100' if you see the approach lights; below that, you need to see the runway environment. I did the 100' decision height under the hood last week.

But nowadays I am more of a mathematics professor than professional pilot, and all I have is the Archer or the Cherokee Six. The Archer has better radios. Neither has de-icing of any kind.

And neither one has two engines.

So the other day when it was time to decide I looked at the METARs and TAFs and the icing forecast and the like. High pressure dominated the Snake River Plain and there were inversions and low fog. No problem! I've landed in Boise when everyone else was missing; there's really no excuse when you have minimums.

The problem was the enroute weather. Burley was at minimums. Twin Falls was forecast below minimums I would have more than one hour's flight time with no place to go when something went wrong.

In a King Air, 414, or even a Seneca, I would have launched. But the same line of reasoning that stops me from flying an Archer (or any other single, except maybe a PC12) across Lake Michigan keeps me from flying the Snake River Plain under fog, at night, with ne enroute alternates.

So I drove. The good part, I thought, would be seeing some new countryside along the unfamiliar route. Wrong: It was too foggy to see much. Sigh.

Mirror Image

2011-01-23T21:00:00.000-08:00

The arrival of a large check brought my Accounts Receivable balance to zero, and flush with cash I set out to keep my instrument currency. Instrument practice on a CAVU day requires a safety pilot, and so I started calling my flying friends. Dale was eager to join me, so we made the arrangements.

Dale and I are among the most prolific contributors to our EAA chapter's newsletter, so I should have expected him to write a flight report. With his permission I present it below.

For me every moment is a teaching moment, and I recommend that you do what Dale and I did: Fly with a friend and read his or her report about your flying. It's good to get that kind of perspective on how you do it.

Oh, skip the 'teaching moment' stuff: It was a fun afternoon!

I went flying with Jim Wolper today as his safety pilot. This is a last minute deal and I have to rearrange some other commitments, but it works out to meet halfway at Blackfoot at 3:00. I arrive a little early when Jim calls to say the Cherokee Six won’t start, so he will have to fly the Archer, like a rich guy deciding what plane to fly today. I drop in on Richard Neves and chat with him and some of his students until I hear Jim announcing on the radio so I go to meet him. He is very cheerful to get some ‘flight therapy’ and eager to try his new GPS, programming it while we wait to take off. Jim gives a running narrative on his actions, probably from his background as an instructor. The sun is straight ahead and causes Jim problems with the glare and with his foggles. These are problems that don’t occur in real instrument conditions. The first approach is an ILS at PIH. Tower asks if he has the current information after he already told them we did in his first call. This is routine anymore. Is there a problem with the localizer and glide slope? The needles seem stuck in the middle. I accuse Jim of having done this before and he says the Archer is an easy instrument platform, but not as easy as a King Air. He elects to touch and go; the first time I have seen this done to finish an instrument approach. We fly nearly to American Falls and turn back in, making an approach that does not seem to be designed to be followed by a landing. Then back to U02 for a GPS approach. On the way Jim flies some VFR, and we divert under a small cloud to prove a point but the outcome is indecisive. We are set up for a straight in, but Jim decides to fly the pattern instead. Richard Neves waits for takeoff with a student while we go around. By now it is a little bumpy with a crosswind but Jim ‘chirps it on’ and we retire to the lounge for snacks and conversation. Richard comes back in the 150 and makes a good landing himself. After chatting with the new owners of the 150 we all get out of the wind in Richards’s hangar for some more hangar flying. I’m glad I was able to take part in this adventure.

Tucson

2011-01-16T10:24:00.000-08:00

The recent tragedy in Tucson has left six dead and many injured, including Congresswoman Gabby Giffords. This is an aviation blog (more recently, more of an aerospace blog), and I am not going to add any more ignorance to the public debate about political rhetoric and violence. But this tragic event has an aerospace connection: Congresswoman Giffords is married to astronaut Mark Kelly.

I met Mark once. Driving up to the airport for a flight with a student, I saw a NASA T-38 parked on the ramp. This is not unheard of, but it's not common either. There had been some mixup about whether a pneumatic starter was available, and after a fuel stop the T-38 was stuck.

"Boy, that guy's really angry," my student said. Not knowing who was on board, I opined that anyone who had a T-38 as personal transportation was probably headed Someplace Important, and the government was losing a lot of money.

I took a picture of Dennis standing next to the airplane and we headed out for our training flight. The NASA plane was still there when we returned. We debriefed the lesson and headed to the lobby. Mark was sitting there at the weather computer.

I walked up and introduced myself as a local instructor. "Look," I said, this isn't the kind of airport we abandon a stranded pilot. We're headed out to lunch -- it's decent Mexican food -- do you want to join us?"

He graciously declined, saying that the needed equipment would be there soon.

And now Mark's wife lies in a hospital room with a questionable prognosis. The availability of a pneumatic starter is trivial in comparison. He is scheduled to command the final mission of the shuttle Discovery, which was supposed to launch late last year. The prospect of a family catastrophe must weight heavily on the minds of those who head to orbit. But Discovery has cracks in its fuel tank and is grounded until sometime later this Spring, so Mark is at her side.

Certainly nobody has asked my opinion, but I have one: I think Mark should stay behind when Discovery is ready. Let me explain.

Many years ago I was intensively training for my Airline Transport Pilot practical test. My training plan was unusual, but it seemed like it was going to be successful. The company had several scheduled freight runs in Senecas, and every morning I would wait for one to return and go fly one instrument approach with the freight dog as safety pilot. The idea was to simulate day-by-day operations as closely as possible, and in that way develop the intuitive connection between pilot and airplane one needs to fly with that level of precision.

As the great chef Escoffier said, a chef must prepare a dish 1,000 times before he knows how to prepare it.

And I was ready. The week before my checkride, though, my mother fell ill and was in the hospital. I called and told her that I would postpone the test and come visit her during her recovery.

"No, no," she said, "This is nothing. Go ahead and take your test."

Unless your mother is a CFI you should ignore her advice on flying. But I didn't. The morning of the test arrived. The Examiner and I tussled about Minimum Equipment Lists (he had clearly never worked with one) and I fumbled a question about prop de-ice, so we were even and went flying.

"Steep turn!" he commanded.

I rolled into a steep turn, just like the thousand steep turns I had done before. Only this time was different: I lost control of the airspeed, then the altitude, and ended up losing 300 feet, a performance worthy of a pre-solo student. I guess he chalked it up to nerves and we continued the test. But everything else went the same way. I flew home at low altitude with my first (and only) pink slip. I failed.

A couple of weeks later my mother had recovered and I took the test again, passing easily.

We teach our students to be aware of the effect that emotions have on flying, but there are more forms of get-home-itis than just scud running. I was in a hurry to get my ATP. I rewrote the lyrics to Dire Straits's "I want my M-T-V" to "I want my A-T-P", and sang it will scooting across the desert in my Taylorcraft. My wife was pregnant with twins. School was starting. I pressed and pressed and pressed and, in the end, I broke.

Mark's wife is sicker than my mother was, and the final mission of the shuttle Discovery is much more important than my ATP. He's getting pulled hard in both directions. The chance of failure on his part is high.

Should he fly?

How can he pass up the chance for a last ride to space, the last chance for a long time? How much training time will be lost if the commander calls it quits?

But he is no more fit to fly than if that bullet had passed all the way through his own brain. It will take the kind of selfless courage we expect of our best leaders for him to ground himself. As much as it will sadden me to hear of him doing so, I hope he does.

Math Myths

2011-01-13T09:21:00.000-08:00

Bruce Landsberg wrote about Math Myths in this month's AOPA Pilot. Here is the letter to the editor I sent about the column.

Since I am both a CFI and a mathematics professor, I was intrigued by Bruce Landsberg’s “Math Myths” column in January’s AOPA Pilot.

The FAA’s Aviation Instructor’s Handbook (FAA-H-8083-9A) details four levels of learning: rote, understanding, application, and correlation. Landsberg emphasizes the rote part of learning, which is unusual in a safety-oriented column. Safety comes from application, which comes from understanding.

To see the value in understanding, consider the role of formulas, which express a lot of information in compact form. In Landsberg’s example of the increase in landing distance from increased speed, he presents a rote rule, but that application comes from under- standing the equation for lift. Correlation occurs when one uses the same equation to understand minimum control speed (Vmc) in a multiengine aircraft.

Many former myths about aviation were dispelled by mathematics. For example, pilots who did not understand the difference between true air speed and indicated air speed thought that they flew faster at lower altitudes. It took the mathematical model of the International Standard Atmosphere, as outlined in the beginning of Aerodynamics for Naval Aviators, to set us straight.

The real danger lies in not understanding that mathematical problems like computing takeoff distance, endurance, and landing distance must be solved before flying. No amount of mathematical skill can compensate for inadequate preflight planning. Flying well demands that we use our whole intellect, not just part.

The mathematics of flying is still not fully understood, especially in the area of atmospheric phenomena like icing and microclimates. We have to rely on “conceptual understanding” to handle these phenomena safely. But the line between conceptual understanding and superstition is very thin. Tackling these problems does not mean that every pilot needs to study more mathematics, but understanding and applying their solutions means that many pilots should.

Janus

2011-01-02T22:18:00.000-08:00

Why not make the first flight of the year a proficiency flight? Commuting was fun, $100 hamburgers are fun, instrument practice is fun, but too much straight-and-level is too much. Only one of my 13-year-old twins has expressed any interest in aviation, but maybe what her brother dislikes is too much straight-and-level, and while I would not turn him upside down, maybe a few lazy 8s would help him get the picture. He said he would come, but he's still struggling to recover from mononucleosis and backed out at the last minute. I gave him a raincheck and went alone.

The first pair of lazy 8s only served to show the poor farmers below that I was rusty, but after a few I started to get the feel. Big grin. Next I set off into the hills to find my daughter's ski trip, but the ceiling was a little too low. I overflew the house on the way to a bunch of accuracy landings. (I quit a little early to save some room in the checkbook to take my son out next week.)

We're already on the fast part of the analemma, so the days are getting longer quickly. I left the airport as the tower turned on the rotating beacon. Nice night...

Now that 2011 has begun, what happened in 2010? I didn't have a medical until late June, and my day job has become noticeably harder, and the glider club's Blanik was grounded by an Airworthiness Directive, so the total was pretty ugly: 57.6 hours, not exactly "professional pilot" territory. That included my personal record glider flight (3.8), one $100 hamburger split with a friend (who has since moved away), one family vacation, one trip to the glider port, and a handful of commutes to our other campus.

I flew no actual IFR (I filed once), and while I am current I am beginning to doubt my proficiency. My idea of proficiency is more exacting than most of the CFIIs I know, so maybe a good Instrument Proficiency Check someplace else would do the trick? At least I'd get a little cross country time.

Chile

2010-12-19T09:03:00.000-08:00

Flying is like the rest of life in that persistence and patience pay. Remember the last couple of days before your first solo? If you were like me, you were impatient for that achievement, so you kept on trying and trying and trying until it all came together. The rest of one's flying career often follows that pattern. Keep trying and trying and trying and it all comes together and something wonderful happens.

So there I was in Chile on mathematical business. Before leaving I had called a guy who called a guy who called a guy who might have know a guy whom I could fly with while there ("Thank you" to John and Rodrigo), but that wasn't going to work out. The first few days had terrible weather, and the mathematical conference was just excellent, so while I was disappointed about the flying the trip was more than worth it.

But, still, I kept trying. So I called another guy, but he didn't speak English and my Spanish wasn't good enough. A Chilean friend offered to call for me, and got the number of a guy who spoke English who called a guy whom I could fly with! He was based at Temuco, my departure airport, so the plan came together: a one hour flight with Brian out of Temuco in a Cessna 172XP, followed by the first leg home in an Airbus 318.

In the USA we are so focused on GPS and IFR that it almost sounds like an insult to call someone a VFR pilot. But it's a compliment; think of Duane Cole, who flew his clipped-wing Taylorcraft all over the country, VFR only, and never missed a show (although sometimes he departed a day early). And that's what Brian is: a highly-skilled VFR pilot who seems to know the whole country of Chile in detail, from flying to visit his cattle ranches. He raises an Angus/Hereford mix.

Like Brian's cattle, I'm a hybrid. IFR and VFR are like my twins, whom I love equally for different reasons. But the only charts I had available were IFR charts, which the Chilean government posts online. As we discussed where to fly, I was looking at the chart and thinking "120 radial for 42NM", but that was not necessary. Brian knew the way. (The 30 mile visibility was helpful, too!)

The Chilean government has lots more information online, including an equivalent of FlightAware and facsimiles of filed flight plans. I can't tell whether this is openness or control.

Brian's niece had recently married a guy form the US and he asked if they could ride along. Of course! Empty seats on a sightseeing flight ought to be a crime!

So we launched out of Temuco. I was in the right seat, but Brian graciously let me do all the flying, so the net.logbook.police can just back off when they complain that I shouldn't have logged the flight. He looked out the window while I tried to follow the stupid 120 radial; after a couple of minutes we could see the top of Villarica volcano peeking out from above the scattered layer and I forgot about the radial and just headed there.

I don't think the airplane had Mode C, because Brian left the transponder on ON rather than ALT. This was good, because I was all screwed up on Chile's hemispherical rules. Here in the US, FAR 91.159 applies: eastbound cruise altitudes are 500 feet above an odd thousand, and westbound we are 500 feet above an even thousand, at least between 3,000MSL and 18,000MSL. This doesn't make any sense in Chile, which is a long narrow country; you can't go very far to the east or west, so the hemispherical rules have northbound flights at odd thousands plus 500, and southbound flights at evens plus 500. We were headed southeast, so I chose 3,500 MSL, but it should have been 4,500 or 2,500.

No matter; soon we were over higher terrain. Brian does sightseeing flights out of Pucón during the summer, so he guided me through the spectacular terrain. There were a couple of places that made me uncomfortable over Lake Caburgua, because there was really no place to land, but the risk/reward ratio was pretty low. Lake Caburgua is lined with beautiful homes, many of which can only be reached by boat (I didn't think to ask about seaplane until just now; maybe I'll send him an email).

The IFR charts I had don't show the large number of grass strips scattered through the countryside.

Some of them were right next to spectacular fly-fishing streams. I used to own a Taylorcraft, and I would love to have one there to visit these mountain strips.

What about soaring? There was a lot of steady ridge lift near the mountains, and the cumulus clouds were popping that afternoon. The thermals were weak (which is nice on a sightseeing flight with folks in back), but they were there. After we landed at Temuco I noticed that the thermals were cycling quite close to the airport. I don't know if this happens every day, but on that day you could have flown a sailplane all day right nearby.

The tower spoke Spanish, although Brian says that they can speak English if they have to. I found them pretty easy to understand. There was no ATIS; Tower or Ground gave us the wind and weather and runway in use, and that part was all very familiar. There was no big red sign at the hold short point, but the hold short markings were the same. I could get used to flying there very quickly.

From a practical perspective, another country on one's resume is some kind of asset, but that's not the point, is it? I met Brian, his wife, his niece and her husband, and some of the folks at the Aero Club. We all had a wonderful afternoon. flying in spectacular scenery on a beautiful day. What else could you ask for?

Oh, I know: can I have another try at that landing?

Where Are We?

2010-12-09T15:52:00.000-08:00

Navigation is one of my favorite things, and I got to do a little bit last night as a passenger on AAL945. From way back in the cabin.

Those of you who have been on international flights in the past few years have seen the moving map displays on the in-flight entertainment (IFE) system, but don't scoff. This was an older 767-300 and rather than individual screens (where each passenger can choose the channel) there were monitors hanging down from the middle of the ceiling. And the passengers all watched the same channel, which featured a movie starring someone not among my favorites.

Those IFE moving maps are pretty funny, too, highlighting either the smallest town in the area or the town with the longest name.

But all I had was the view out the window. I could (barely) see what appeared to be the two pointer stars in the Big Dipper, and they were pointing at the tail of the airplane. Just like they should! It was hard to be sure, because the rest of the Dipper was below the horizon, but the orientation looked about the same as it did at my N42W112 house.

So now I had an idea where the North Star (Polaris) was.

Polaris is not exactly over the North Pole; almanacs have tables showing how to correct for its motion. But its angular distance above the horizon (its altitude) is a pretty good estimate of your latitude.

Then I used another old trick: a fist at arm's length subtends about 9 or 10 degrees. (Try it: start at the horizon and go fist-over-fist to the zenith.) Using that, I estimated that we were about 10 degrees North.

Another key axiom of navigation is that you don't know where you are until you know where you're not. The Marcq Ste.-Hillaire or Sumner Line methods of Celestial Navigation depend on this axiom. It involves a couple of steps:

Take a guess where you are; this is the assumed position;

Calculate the altitude of a star or planet, based on that guess;

Observe the altitude;

Using the difference, adjust the assumed position. That's your fix.

In this case, I assumed that I was at N10W095 at 0700Z. Today I went to an online star chart to look at the night sky from that position at that time. Here's what it showed me.

And that's what I saw! So, in retrospect, my estimate was pretty good.

As the night wore on (and it was a long night, over 9 hours) and the Dipper rose, the pointer stars pointed further and further down, until they pointed below the horizon. In other words, we crossed the Equator.

And then I was stuck: I don't know the Southern hemisphere constellations. Besides, it was time to sleep.

There are no navigational heroics from row 36, so here's a real story. When Amundsen and Nobile were flying the airship Norge from Spitsbergern to Alaska by way of the North Pole, it was very difficult to fix their position. The navigator, Riiser-Larsen, couldn't take sights from the gondola, so he climbed up to the roof of the ship to take sextant sights while exposed to the 60mph Arctic (relative) wind.

(This doesn't have much to do with my flight, but I thought it would be fun to mention the Norge in two consecutive posts.)

The International Space Station

2010-12-05T14:16:00.000-08:00

This month was my turn to present something to my writer's group (we each do two a year). This is a diverse and distinguished group, and sometimes I wonder whether I really belong. Our common interest is what used to be called Natural Science, with an emphasis on geography. Some are scientists, and some are not. There is one engineer. They are not pilots. Well, we had one pilot (my student, of course) who left to become Dean of a university in Texas. Another's mother was a pilot, in the 1950s, but we never seem to connect when I try to take him flying.

This means that I have simplified some of the scientific and engineering material. Anyone who has tried to do this knows how difficult it is to balance correctness with simplicity. One thing I would like is for those who know more about the ISS than I do to point out any inaccuracies or mistakes.

Most of my presentations are not aviation-related. For example, I have written about the etymology of animal names, naturalist Carl Akeley, mapping of the Great Basin, and the dust bowl.

The ISS is not really aviation-related, either, because rocket science is not aerodynamics. But I feel that there is a strong relationship. With no apologies, here's what I said.

iPhone Picture of ISS, November, 2010

For the past few months, when conditions have been favorable, I have gone out in the evening or early morning to watch the International Space Station (ISS) fly over. A few people have come out with me to see it once or even twice, but I've watched it dozens of times. The repetition has permanently changed my perception of the Earth's place among the stars.

The Space Station is full of contradictions. It doesn't travel among the stars; instead it barely skims above the Earth's surface. It is often closer to me than Denver, but it is impossibly far away. From the perspective of Voyager 2, which at a distance of 15 light hours or so is out of our solar system, the distance from the ISS to Earth amounts to a rounding error. It travels at about 17,500 miles per hour, but it does not go anywhere. It is not a flying machine, although pilots seems to love it, and the astronauts are generally pilots. Few astronauts are scientists, but the ISS is billed as a science laboratory.

It is a bureaucratic boondoggle, a tool in search of a need, the creator of its own necessity. My rational, political side sneers. But I still go outside to watch it pass over.

Some people marvel at skyscrapers, or bridges, or tunnels. Some go out of their way to see the great dams, or the Great Wall of China. My high school had a policy by which students on the Honor Roll could skip one day each term; I used an honors holiday to tour the first Boeing 747 to land in Boston. The ISS is a source of wonder and, to some, inspiration. After all, how many 1,000,000 pound objects can you see moving?

Consideration of the ISS takes many forms: scientific, engineering, political, psychological, medical, to start the list. Any one of these would take more than an evening to discuss.

I think the most important of these is that the ISS is in space. While I suppose that some might find the station itself pleasing to look at, its beauty for me lies in its perspective on the planet. The inside -- I've toured mockups and watched videos -- has the cubicle look of an Air Force base. But no Air Force base I've visited has such a good view out the window.

Orbital Mechanics

The science of the Space Station is, without sarcasm, rocket science, and one of the first things one must understand about rocket science is that in space everything you know about the physical world is wrong. Everything you know either depends on gravity or on the atmosphere. And while objects in orbit are influenced by the Earth's gravity, once in orbit everything in your world is falling together, so there is no perception of relative motion. When an astronaut lets go of a fork, it appears to hang there as they fall together. This much is amusing. But now consider a fuel tank. If you put a valve at the bottom of the tank, the valve and the fuel will continue to fall together, so the fuel will not flow. This is a serious engineering problem.

Sleeping astronauts are in danger of suffocating in the bubble of exhaled carbon dioxide that builds up over the course of the night. On Earth, the CO2 falls to the floor, but in microgravity it just hangs there. Sleep areas must be well ventilated. Nothing is left on the bedside table. The bubbles in a carbonated drink won't rise to the surface, and a popped champagne cork would lead to a plume of champagne that continued until it hit a wall.

Salt and pepper shakers make no sense. A pepper mill without gravity is a sneezing fit waiting to happen.

Whatever else happens in our world happens in reference to up. But on the ISS there is no well-defined ``up." Astronauts refer to the nadir, meaning toward the Earth, and the zenith, meaning away. But there is no up.

Newton's insight that a falling apple and the Moon both respond to the same force seems a commonplace to us, but actually encompasses a remarkable breadth of vision. While Kepler had derived the laws of orbital mechanics empirically, there is an air of mysticism about Kepler's work, and much of it contained mutually-cancelling errors. But Newton started at a simple and reasonable assumption, the inverse square law, and derived the consequences.

Newton's First Law of Motion is that every object in motion tends to stay in that state of motion unless an external force is applied. When you throw a ball, you apply an external force, but as soon as you let go the ball continues to move in the same direction at the same speed. Actually, that would be the case without gravity; but the external force of gravity changes the motion of the ball.

When the engines on a rocket stop, the rocket continues to go in the same direction at the same speed, so by the First Law the rocket should continue in a straight line away from the Earth. But, again, gravity takes over. That initial velocity makes a big difference; a rocket that was launched straight up would just fall straight down, although unless launched from the North or South pole it would land someplace different because the Earth would have moved during the flight.

When the rocket stops, it needs to be going in the right direction and at the right speed. In addition, the rocket sitting on the launch pad is already in motion, due to the rotation of the Earth. At the equator, the Earth is rotating at a little over 1,000 miles per hour, while at 45 degrees north the speed is reduced to about 745 mph. That's why launch sites are clustered as near to the Equator as possible; Arianspace, a European consortium, launches from French Guiana, very close to the Equator.

STS-124 Altitude

What's remarkable is that many space shuttle launches include a descent. For example, 5:38 into the launch of STS--114, the shuttle had reached an altitude of 67.57 miles, and was travelling at 8,649 mph. It then descended to 63.71 miles over the next 2 minutes or so, accelerating to 15,596 mph, nearly doubling its speed. The engines were cut off at 8:34, with the shuttle going 17,609 mph at an altitude of 65.14 miles.

The Orbital Plane

A launch trajectory defines a plane in space, and the spacecraft cannot leave that plane without a large expenditure of energy, which means a large expenditure of fuel. This is part of the reason that missions requiring rendezvous have a ``launch window;" the target must be in position when the vehicle gets there, and the vehicle has little ability to adjust.

The ISS orbital plane is tilted about degrees from the Equator, which means that the station passes over most of the inhabited regions of the earth. The station always stays in the same plane, while the Earth rotates below, so it appears in different parts of the sky depending on the relative geometry.

Orbital Mechanics

Orbital maneuvering is another realm in which everything you know is wrong. We are accustomed to thinking of flying machines, with the exception of balloons, having the ability to maneuver any which way. Add thrust to go faster, add drag to go slower.

But an aircraft turns by aerodynamic forces. Filmmakers expect the audience to know this intuitively, so they show spaceships banking in order to turn. This makes no sense in space. The only way to turn is to apply thrust to the side of the orbit, parallel to the Earth. This is far more expensive than turning an airplane, and most of the spacecraft that we have launched have extremely limited ability to turn. Maneuvering consists of moving faster or slower so that the space craft is at the intersection of two orbits at the same time as its target.

Kepler's Laws, as refined by Newton, lock an unpowered satellite's speed to its altitude. Higher speed satellites must be in lower orbits. A satellite in low Earth orbit passes under one in geosynchronous orbit about 16 times each day.

The Atmosphere

Although the sensible atmosphere only goes up to about 100,000 feet, there are enough stray molecules in low Earth orbit, and the ISS is so big, that atmospheric drag is a factor in operations. Each collision with a molecule uses a little energy, so not only is the Space Station falling in the Newtonian sense, it is falling in the colloquial sense of losing altitude. In one 24-hour period last week, the station lost 78 meters in altitude; some days it loses 200 meters.

The remedy is to dock with a Russian ``Progress" module and use its engine to boost the orbit. A reboost last Wednesday added 1.77 km of altitude. This took 7m38s. The Shuttle and Soyuz spacecraft also act as boosters.

Of course a reboost disturbs all of the microgravity experiments.

Station Attitudes

Orbital boost means that the station has to be pointed in the right direction. The Progress or Shuttle is docked to the station in a rigid way, and its thrust must point to the nadir.

What about at other times? What, exactly, is the right direction?

The debate about which way a spacecraft should point began with project Mercury, the single seat ``space capsule" of the 1960s. Airplanes have a preferred direction that minimizes atmospheric drag, and maximizes the effects of thrust. But there is not enough drag in low Earth orbit to make aerodynamic design effective. And spacecraft don't use thrust in the conventional sense; they merely fall, with style.

The flights of John Glenn (Friendship Seven) and Scott Carpenter (Aurora Seven) were plagued with flight control issues. There was no problem with the path of the ship; that had been determined through Laplace's calculations a century earlier. But there was a problem keeping it pointed in the so-called ``right direction", with the astronaut facing forward, his head at the zenith. From a navigational standpoint, the only time that the ship's attitude really mattered was when the engine was fired to start reentry. In Carpenter's case, an instrument failure forced him to fly the re-entry maneuver manually, and he landed over 200 miles from the planned area.

(The Mercury capsule had three different attitude control systems, and astronauts got confused and used fuel from two or more simultaneously; this contributed to the control problems.)

The next flight, Wally Schirra in Sigma Seven, featured long periods of ``drifting and dreaming"; Schirra allowed the spacecraft to point in whatever direction it pleased for long periods of time.

Schirra depended on batteries for electric power, but the ISS uses massive solar panels, so it can't just drift. Its solar panels are the size of a football field, and create noticeable atmospheric drag. They must be pointed so the sun hits them, but this is difficult. There are two basic schemes. The less intuitive one is inertial; the space station is always oriented the same way with respect to the stars. The more intuitive one is the opposite of Schirra's flight: the same side of the station is always pointed toward the Earth, kind of like an airplane. NASA says that this orientation is best for microgravity experiments, but I'm not seeing this intuitively. Keeping this attitude does not require thrusters; momentum wheels are used, which, owing to the gryoscopic property of rigidity in space, keep the station pointed correctly.

Earth's Shape and Composition

While everything that we do happens in reference to up, the concept of up is more complicated than it appears. In geodesy -- the study of the Earth's surface and composition -- there are three common definitions of ``up," and they don't quite agree. Latitude is the complement of the angle between up and the Pole.

The first complication is that the world is not flat. Anyone who doubts this needs to spend an evening or two watching the space station and the many other satellites in orbit. But the Earth is not a sphere, exactly. It's wider at the equator than at the poles, and it's slightly pear--shaped.

One way to measure the vertical is to use the line through you and the center of the Earth. This is called geocentric latitude. Following that line is surely ``up," but how could you ever measure it?

Another measure is the normal -- the perpendicular -- to the tangent plane at your location. We call it geodetic latitude. This is slightly different from the first, in a measurable way, because the Earth is not a perfect sphere.

The final measure is the direction of gravity, which is called astronomical latitude. As [former member] explained last spring, the Earth is not homogeneous, and so a plumb line is attracted -- measurably if you're careful enough -- toward the denser part. The Rockies are less dense than the iron-rich regions around the Great Lakes, so a plumb line in Kansas tilts just a little to the northeast. A satellite feels the same pull as the plumb line.

This is more of a problem for the Global Positioning System satellites than for the ISS. People use GPS to measure in centimeters, so the satellite orbits are measured with at least that precision. Following the orbits with that precision is the full-time mission at Schriever Air Force Base.

By the way, the ISS has GPS receivers, but these are not a primary navigational tool. There's no need to navigate; it's not going anywhere.

Astronauts

First let me make a statement of conflict of interest. I applied to the astronaut program about 1990. My application didn't even make the first cut.

The astronauts are cheerful overachievers, traditional leaders. I'm sure that some of them are characters, but the public face is cheerful and loyal. Most have a military background, and military morale seems to require extreme loyalty to one's platform. F-18 pilots think they have it better than F-16 pilots, who are much better than F-15 pilots, who are far superior to F-18 pilots. Submarines are more effective than aircraft carriers which are obviously superior to Air Force Bases which are far superior to submarines.

And so there is no surprise in hearing astronauts praise the Shuttle, or the Space Station. With some of them a critical ear can detect the cant, but in a few their joy and wonder sound genuine.

Wisdom on the choice of a crew for a long expedition has been passed down from expedition leader to expedition leader. Before departing to cross the North Pole in the airship Norge, Amundsen told Byrd that ``[m]en are the doubtful quantities in the Antarctic. The most thorough kind of preparation, the shrewdest plan, can be destroyed by an incompetent or worthless man." An unnamed British explorer from Robert Falcon Scott's ill-fated expedition to the South Pole told Byrd ``The first man who starts trouble of a disloyal nature deserves the worst death you can think of."

The crew eats breakfast and dinner together, then go about their daily business. It's probably a lot like the Air Force labs where I
have spent some time. Some tasks are solitary, some take two people.

But then they have free time. Free time means looking out the window. It seems that everywhere one turns in the station, there is a laptop, and I wonder how many YouTube videos get watched. TV is difficult, because the station moves too quickly to track any ground or in-orbit stations; presumably there is internet upload.

The skeleton crew aboard the ISS last weekend had the weekend ``off." I'm not quite sure what that means. I can imagine writing a novel during the off time, or studying Spanish, or working on a software project; but what about the plastic hobbies? You can't build a chair or install a weathervane.

Lately, some of the astronauts have been using Twitter. Some ``get it", others don't. Twitter allows 140 characters in a message, so flexibility and improvisation are in order. Soichi Noguchi, a Japanese astronaut, is a talented photographer (photos only require a few characters), and had the advantage that 140 characters of Japanese carry a lot more information than 140 characters of English. Doug Wheelock, who commanded expedition 25, didn't get it, and his messages were always truncated.

But Wheelock is active in ham radio; hams live in their own universe and always have something to talk about.

Many just keep their heads down and do their work. What is their work exactly? It's mundane housekeeping, space-style. Here's what happened on Thanksgiving. Inspecting the aerosol filters for the oxygen generators. Transferring data from body sensors or other experiments for downlink. Toilets need lots of maintenance; toilet issues appear frequently.

One cosmonaut worked on preparing the Soyuz capsule that would return him and two astronauts to Earth on Friday.

There are also training sessions with the various robotic arms; this sounds like real astronaut work!

Pilots and the ISS

While I have done no formal research, it is easy to imagine that many pilots are ``fans" of the ISS. It is certainly the case that many of the astronauts are ``fans" of flying.

In the space shuttle, two astronauts sit ``up front", the Commander and the Pilot. The Commander is really the pilot, and the Pilot is really the copilot. The Commander flies the shuttle to its landing, although there is a tradition that the Pilot is allowed to handle the controls for a few seconds, during a non-critical moment.

The computers fly the shuttle for takeoff.

Everyone else in the shuttle is a Mission Specialist, and Mission Specialists do not handle the flight controls. Remarkably, many Mission Specialists list flying as a hobby, and hold advanced ratings. But this is a hobby, not part of the job.

Still, the pilot personality is probably a good fit for this kind of mission. More specifically, the professional pilot personality is a good fit; the amateur pilot personality is not. This division of pilots into personality types is certainly crude, and the division is independent of whether a pilot is paid to fly. The professional pilot loves every aspect of flight, while the amateur finds some of the details to be tedious and boring. The amateur jumps in and goes, while the professional enjoys the process of preflight preparation.

Preflight preparation for an astronaut is pretty extensive, too, measured in months or years rather than minutes.

Each ISS Expedition has a Commander, a Commander-to-be, and a handful of Flight Engineers. There is no pilot! The Space Station has no cockpit. The Space Station does not fly: it falls with style.

Rendezvous and docking seem to be much more like flying. Military pilots and glider pilots routinely rendezvous with other aircraft, although we do not touch each other. There are some differences from ordinary formation flight due to orbital mechanics, but a delicate touch is required in any event. The Shuttle docking is apparently hand-flown, while the Soyuz and Progress dockings are flown by the computer.

I have a simulator program for docking; I succeed about every other time. Watching a Soyuz docking live, though, I was impressed with the simulator's accuracy.

Scientific Value

The scientific mission of the ISS is, to a large extent, self-generated. Many experiments focus on the effect of long-term spaceflight on the human body; in other words, we need the ISS in order to study the ISS. Other experiments have focused on combustion, crystal growth, and microbial development. I am excessively judgmental, but my impression is that the science is pretty weak. The real achievement is in the engineering.

Cultural Value

I think the right cultural context for considering the ISS is that of polar exploration. The metaphor is brought home by the naming of crews to the ISS: Expedition 25 ended last week, and Expedition 26 will begin soon (the crews overlap so the station is not left empty).

While Scott's Terra Nova Expedition of 1911 tried a ``new" technology in the form of ponies and motor sledges, Amundsen's expedition relied on proven techniques for travel on the ice. Amundsen did no science, making his task much easier.

(When hiking in the Rockies I often think about the men who carried heavy surveying equipment along the same trails.)

Since Amundsen, exploration has been driven by new technology. Byrd's Arctic and Antarctic expeditions exploited something new, the airplane. Nuclear propulsion enabled the submarine Nautilus to reach the north pole.

But orbit is not a place.

In each case, resupply and logistics are major hurdles. Amundsen marked his caches carefully, while Scott did not, and Scott starved to death. The ISS has been resupplied by the Shuttle and by various Russian craft. The current political climate makes refurbishing of the Shuttles impossible; the penultimate mission is planned for this month. But the political climate in Russia strikes me as less-than-stable, although the presence of Russians on the station would seem to guarantee some kind of will to resupply.

Scott and Byrd had corporate sponsors; only Byrd's third Antarctic expedition had government support. NASA now is moving toward supporting commercial space efforts. Byrd and Amundsen bought supply ships on the open market, so there is plenty of precedent, but in that sense they were using existing technology, not developing new technology. The closest we have to private space travel, barring a few eccentric billionaires who bought their way onto Soyuz missions, is Sir Richard Branson's Virgin Galactic effort. Virgin Galactic has built a space port in New Mexico and a suite of aircraft modeled after Burt Rutan's Space Ship One. A mother ship ( White Knight Two) carries the space ship Space Ship Two to around 50,000 feet, where it is dropped. The rockets are fired and the space ship leaves the atmosphere and climbs to ``at least 110 km." For reentry, an innovative feathering arrangement is deployed, and once into a thick enough atmosphere the wings are unfeathered and the ship becomes a glider.

I wonder if the Virgin Galactic enterprise will be attractive to microgravity researchers. For $200,000 and a few days' training, a researcher could get 4 minutes of microgravity

Conclusions

When the conditions are right, an Earth-bound observer can watch the station pass into eclipse. In these conditions it is especially bright. I watch it turn from hot white to dusky red as it reaches twilight, and then it disappears.

Imagine what it looks like from inside.

Blow-up of iPhone photo of ISS

Request for Information

2010-12-01T20:19:00.003-08:00

Does anyone have any aviation contacts in Chile?

Duck, Duck, Goose

2010-11-11T14:14:00.000-08:00

My student Dan is hustling to finish his Private before he has to move, so we've been flying every day. This has required a little creativity on my part since my University workload seems so much heavier this semester.

Yesterday afternoon was turning into yesterday evening after an unusually moist morning. The ceiling was on the low side, but not too low to stay in the pattern. Turning downwind for the first time I saw about 40 geese flying just a couple of hundred feet above, headed north. I swear, they were heading north! I mentioned this to the tower, but the radio call included "Oh! There's another flock! And another! And another!" The birds actually winter in the nearby marshes.

Another airplane was out flying a practice ILS, and the tower duly warned them about the birds, and I felt like a good citizen. And, sure enough, every pattern brought a new bird sighting.

"Birds, 10 o'clock," I would say. On the first few patterns Dan acknowledged, but soon he was no longer seeing them. Experience really does make a difference.

And the birds were getting lower. A flock of 25 or so passed below us, and in the gathering twilight they were getting harder and harder to see. Dan didn't see the large flock even though they were very close.

I started to think how lucky we were not be flying at night with so many birds in the pattern. Lucky? With the clouds and the glare, it was already night, even though the regulations say that we had an hour of "daytime" left.

So we called it a day.

Too Good?

2010-11-09T15:54:00.000-08:00

The pattern in Pocatello was all ours, which was good. Strong south winds meant that runway 17 was in use, and that traffic patterns were pretty distorted. I was flying with a student, and we had calculated the crosswind component; it was waaay beyond his current skill level. The tailwind meant a quick downwind leg, but he was keeping up.

A Mooney taxied for departure on 17 to stay in the pattern. Now there would be two of us in the pattern, which is not usually a problem. Then a Skyhawk taxied for departure. I recognized the pilot's voice: a good friend who is also one of the most skilled pilots I know. He asked to depart runway 21; the crosswind was not pushing his skill level. But notice that the departure paths for 17 and 21 intersect...

"Oh, no," I thought, "this could get interesting."

The tower had us fly runway heading off 17 to make room for the Skyhawk departure just as the Mooney using 17 called "Ready." When the tower cleared the Skyhawk for takeoff, the Mooney thought that he was cleared. The tower stopped him quickly, but the frequency was tied up while everyone straightened this out.

And now we were flying toward high terrain. I wished I had brought my Garmin so my student could watch the "Terrain" window pop up with the big red X's denoting where we were going to hit the mountains.

The tower cleared us to start a left crosswind as soon as the 21 departure was airborne. Whoops! We didn't have enough of a wind correction, and our square crosswind leg was really a diagonal to the midfield point on the downwind. This put us directly over the departing traffic, and I asked my student to fly behind it.

Worse, the departing Skyhawk was headed northeast, right through our downwind. So we got to do a 360 to let it out.

Once the Skyhawk was high enough, ATC cleared the Mooney to go. Now we had three airplanes pointed at the same piece of sky. The Mooney's pattern was distorted by the wind, too, and he ended up following us too closely and had to go around.

When things get interesting it's worth examining the chain of events that got us there. You can't really blame the Skyhawk pilot; when he called and requested 21 he had no way to know that there were airplanes in the pattern for 17.

You can blame me a little bit for not flying a square crosswind; that would have saved us the 360.

You can blame the Mooney a little for mishearing the radio call, and poor planning in the pattern, but the wind was an extenuating factor.

But you can blame the tower a lot. With two airplanes in the pattern for 17 the proper reply to anyone requesting 21 is "Unable."

Now somebody might insist on using 21 for length reasons, but then there will be a delay. This reminds me of a story from many years ago. I was in the jumpseat of an Airbus 320 departing Boston. It was the FO's leg. "We're 4000 pounds too heavy for runway 4L," he declared. There were 15 airplanes taxiing to 4L and 15 more on final to 4R.

"What do you want to do?" the Captain asked.

"We need to use 15R." Runway 15R crosses both 4L and 4R.

"OK," the Captain replied, maybe rolling his eyes just a little bit. And we taxied to 15R. We weren't going anywhere with all of that crossing traffic, and the FO was jumping out of his seat, shaking his fist at the tower, and yelling "It's not that busy here!" The Captain just smiled. By the time we were cleared for takeoff, we had burned so much fuel that we would have been light enough for 4L.

Back in Pocatello we had another option: if the Skhawk had done a left downwind departure before turning north the runway 17 traffic would have been able to continue in right closed traffic.

But nobody thought of that at the time.

What Goes Around...

2010-11-04T22:34:00.000-07:00

Last Saturday's EAA Young Eagles rally in Blackfoot, ID was a bit of a disappointment. Somebody had dropped the ball on publicity, and there were a lot of chapter members milling around and socializing because there were no kids to fly. I walked the line and visited a friend's hangar; that seemed like it was going to be the best of it. Oh, except for the cookies. A chapter member passed away suddenly last summer (not aviation related), and when our president asked people to bring cookies for the memorial service we all pulled together and brought cookies. There were far more cookies than even the large crowd could eat, so the president keeps them in her freezer and brings some to chapter events. We all miss John, especially at Young Eagles events, so the cookies are a bittersweet reminder.

Finally some kids showed up and I got to take a brother and sister on a search for their house, which we found easily. They were so excited! I took a cell phone picture and emailed it their mom after we landed. They really enjoyed the flight experience and I did, too.

But now we were back to the lots of pilots standing around scenario. I got an idea: this was a great opportunity for some IFR proficiency flying. It was easy to find an eager safety pilot and even another pilot who rode in back for the fun of it.

So I did an ILS and a hold and headed back to do the VOR approach into Blackfoot. The VOR approach into Blackfoot is a little silly, starting at Pocatello VOR and following the 016 radial for 24 -- count 'em, twenty-four! -- miles. Being that far from the VOR the obstacle area is pretty large, so the minimum descent altitude is actually above the ordinary VFR pattern altitude. Plus, you're flying away from the nav source, so the needle gets less sensitive as you get close to the airport.

Worse, the approach shuts down both Pocatello (KPIH) and Idaho Falls (KIDA), at least for a while. Pocatello is a long way from Salt Lake Center's radar antenna, so it's not clear to me that radar separation is even possible; in any event, the separation criteria are loose enough that someone on the VOR-C into Blackfoot is also taking up the airspace for the ILS into Pocatello. And the missed approach is Idaho Falls VOR at the airway MEA, so nobody's getting into IDA, either. For a long time the approach was NOTAMed out of service.

(I had a hand in designing the Pocatello ILS, but nobody asked me about Blackfoot. One of the approaches in the original draft for Pocatello had a missed approach point at an airway intersection 500' above the MEA, which was 7000 MSL. This meant that 7,000 and 8.000 were unavailable on two airways, shutting down low-altitude IFR traffic for a 60 mile radius.)

But a logged approach is a logged approach, and I was going to Blackfoot, so I flew it. At the right point I lifted the hood and entered the pattern, making the usual calls on downwind, base, and final. While we were gone, though, some kids had shown up, and there were airplanes in the runup area. No big deal. Until when we were about 100'AGL, a red Skyhawk took the runway and started his takeoff roll.

Ouch.

I went around.

Blackfoot was the site of the near gear-up landing a couple of weeks ago. I think I'll avoid it for a while...

A Weighty Matter

2010-10-27T16:25:00.000-07:00

Here in the USA flight instructor certificates expire after two years. There are several ways to renew; when I was instructing in a charter operation, renewal was a matter of catching the FAA inspector while he was in town, but now I find the most convenient way is through a Flight Instructor Refresher Clinic [FIRC], a 16 hour approved course. The Idaho Department of Aeronautics runs a good one, and Frank Lester rotates them through our rather large state, so everyone gets a chance to attend. Better yet, he offered to let me attend for free in exchange for teaching some of the segments.

When I told my university students that I would spend the weekend attending a 16 hour course they recoiled in horror. When I told them that there would be a test they were impressed.

Usually I believe that what happens in the Pocatello Holiday Inn stays in the Pocatello Holiday Inn, but due to popular demand here are some ideas from my presentation on Weight-and-Balance. The most striking thing to me was the central role of weight in all aerodynamic questions.

Glider Nerd Calculations

Consider a 3000 pound airplane in level flight at constant airspeed at 100 knots (true airspeed). A reasonable lift-to-drag (L/D) ratio might be 10; see the graph above, taken from The Pilot's Handbook of Aeronautical Knowledge. In level flight, thrust and drag are equal, as are weight and lift, so we have 3000 pounds of lift. Since L/D = 10, this translates into 300 pounds of thrust or drag, depending on your outlook on life.

An airspeed of 100 knots is just about 10,000 ft/sec, which translates into a (300 x 10000)/33000 = 91 Brake Horsepower required.

Rate of Climb depends on excess thrust. Most people don't appreciate this until they study multiengine aerodynamics, but it applies as well here. The formula is

where E is excess thrust and W is weight. Suppose that the airplane has
140 HP available, which is reasonable for a normally-aspirated engine at altitude. Then the excess thrust is 140 - 91 = 49 HP, and the rate of climb is

Change the weight to 4000 pounds, however; the L/D does not change (it's a property of the wing), and now we have (400 x 10000)/33000 = 121 Brake Horsepower required. The excess thrust is down to 19 horsepower, and the rate of climb becomes 156 ft/min.

Why do multiengine pilots learn this? Take the 4000 pound airplane at 100 KTAS and give it 400 horsepower available; this is about right for a Seneca. When both engines are turning there are 279 HP of excess thrust available, for a whopping 2300 ft/min climb. Yee-haw! But kill one engine and the excess thrust available is now 79 horsepower, and the rate of climb is down to 650 ft/min. This isn't bad (4000 pounds is light for a Seneca), but the drag picture is a lot worse, too, so L/D has gone down and there is even less excess thrust. The point is that losing half the power costs you WAY more than half the climb!

Change the L/D to 8 and the weight to 4500. Now, at 100 knots, the horsepower required goes up to 170; with only one engine turning there are 30 HP of excess thrust, for a rate of climb of 125 ft/min. At 100 knots you travel forward 10,000 feet in one minute, and the climb gradient is an anemic 75' per nautical mile; the climb angle is less than half a degree.

(Why is the elevation relevant? At higher density altitude the same indicated airspeed corresponds to a higher true airspeed, and hence to more horsepower required.)

I took my Multi-engine Instructor flight test in a Seneca on a hot day at about 4500' MSL. Even though it was in a Seneca (so I had sea level power), when I demonstrated an engine failure to the examiner the airplane would not climb. I headed out across the desert and finally found a thermal that took us to pattern altitude. The moral of this story: always think like you have an even number of engines!

Foolin' Around

2010-10-18T21:07:00.000-07:00

We were really just foolin' around, headed to our EAA chapter meeting. My friend had called and offered a ride in his airplane. It wasn't instruction, just a ride.

"You fly, I'm going to take advantage of this chance to play with my new GPS," I said. And, given the luxury of being a passenger, I put my head down. I was reading IFR plates off my iPhone and setting up the approach in the GPS. And taking pictures with his camera.

As we turned downwind, the radio crackled "Blackfoot traffic, Cessna [whatever], taking runway 1 9 for departure."

We both looked up, trying to find the traffic. Was that the Cessna or the numbers? It was almost dusk, and hard to see. My friend asked the Cessna where he was, and he claimed to be well clear.

We turned base. I looked down at the GPS to check the extended centerline.

We turned final. I scanned the panel, out of habit. After all, I was a passenger.

"Hey," I asked, "how come we don't have any green lights?"

We went around and did the pattern right. The wheels felt good on the pavement.

Karma

2010-10-08T14:52:00.000-07:00

The weather looked a little iffy so I had filed IFR the night before. In the morning the weather was good, but I decided to fly the trip IFR anyway.

At the hold short line I called "ready." The tower told me to hold for release due to an inbound SkyWest Brasilia. Before i could say "I'll depart VFR," though, the Brasilia cancelled IFR.

Now I was in karmic debt.

Fifteen miles from the destination Center cleared me to climb so he could release a SkyWest RJ. "How about `cancel IFR'?" I came back. "Those are the magic words!" he replied, and I continued my descent.

SkyWest cancelled for me. I cancelled for SkyWest. Now I was in karmic balance.

Reverse Sensing

2010-09-28T20:36:00.000-07:00

I've been flying various models of Piper singles and twins since my first introductory lesson in a Cherokee 140 in 1970 or so. Most of them have an autopilot, and the autopilot has strengths and weaknesses. When I was a check airman in Senecas the FAA required everyone to demonstrate a "coupled" approach, that is, an instrument approach flown by the autopilot. We studied the limitations and regulations (mostly about minimum altitude for autopilot use). And we knew that they were sometimes flaky, so I always told the pilots I was checking "If you do the right thing but it doesn't then you pass."

So I thought I knew the autopilot well.

But there I was this morning, approaching Idaho Falls from the south. "Make straight-in approach runway 2," the tower told me, and since it is my habit to brief an instrument approach for every arrival, I had the approach programmed both in the VHF navigation instruments and in my GPS, even thought the weather was CAVU. "I'll just follow the back course," I said to myself.

I had the autopilot in heading mode for the approach brief (hand-flying while briefing an approach makes life too difficult) and went to adjust the heading bug to track the back course. "Hmm," I thought, "in all these years I have never put the autopilot into 'LOC REV' mode." This is supposed to track the backcourse by using reverse sensing.

So I tried it for the first time.

It worked great.

There's always something new to learn.

Who's Got The Touch?

2010-09-27T19:56:00.000-07:00

What is it about flying that feels so good? We've both puzzled over this for years, right?

I appreciate a pretty mountain valley, breaking out of an ILS at minimums, sunrise over the Tetons, and the other wonderful sights we see from the air. Circling with other gliders is a beautiful, dynamic (and dangerous: there was a fatal mid-air in Texas in August) delight for the eyes.

I appreciate the wonderful people I've met through flying, and even the not-so-wonderful ones (I remember thinking "Now I know why your wife divorced you" while one difficult student flew.) I wouldn't give that up for anything.

Instead I wonder about how flying feels.

The aeronautical engineer wannabe in me has a rational reply: Flying straight and level means that you don't feel anything. It's no different from sitting in the living room. There are no accelerations or forces. In gliders there is little vibration. No, there is nothing to feel about flying.

Baloney.

Some kind of feeling is coming back to us through the stick or yoke. No, that's not right, you don't even have to have your hand on the controls. Once, back in the pre-9/11 days, I was jumpseating (that is, riding in the cockpit) in a Boeing 737 from San Francisco to San Diego. The 73 was familiar, as were both airports, and I was focused on the transportation (and being in San Diego for Spring Break!), not flying.

We taxied to runway 1L, all very familiar, while the captain and first officer ran their checklists. "United blah-blah-blah turn left heading two-niner-zero, runway one left, clear for takeoff." Oh this is just too boring and routine. Yawn.

The captain advanced the power levers. Wait, there's no flight director; she's staring at a plain attitude indicator. Is this a mistake? Should I say something? I decide to keep my peace. We start to roll. "V1," says the FO, then quickly, "Rotate!"

And then I knew: she had the touch. As I looked out the side window at the familiar GA parking area, although from an unfamiliar angle, I felt that this airplane was in the hands of a master. The rest of the flight went the same way.

So what is this "touch" that you can feel even from the jumpseat? I think it's related to another touch, the healing touch. I've felt this from a few physicians. My childrens's pediatrician is a former big-10 quarterback. Once as I left his office with one my children he patted me on the shoulder to wish me well. He has the touch! He can heal just by "laying on hands." Send your children to this guy.

Most of us don't have this touch. That does not mean that we cannot be good pilots, and it does not mean that we cannot fly smoothly; it just means that we have to to work harder at it. And it means that we have to find joy in that work.

But what kind of work? I had a recent revelation about this. I have practiced Tai Chi Ch'uan, the Chinese martial art, for many years. I don't make a big deal of this, and many people have no idea that I do it. Tai Chi has improved my balance and proprioception, and I am at least a little more relaxed. I've also made good friends through Tai Chi.

The center of Tai Chi practice is the form. Different schools have slightly different forms, but no matter the specifics the form is essential. One of the too many things we try to be aware of in practicing the form is what one teacher calls "The Tai Chi ball": At certain points, your hands (relaxed into the beautiful lady's wrist position) face each other. You can feel something there, which of course you cannot see. That's the Tai Chi ball. Some days it's large, some days it's smaller, some days it's vibrating. But there's nothing there!

In Aikido there is a similar concept of the unbendable arm: Imagine water shooting out your fingers to a point across the room, and suddenly your arm becomes infinitely strong. I use this during the trickier balance portions of tehe Tai Chi form, shooting water to the ceiling and using that to hold myself upright. I once described this to a teacher as "cheating", but she just shrugged.

Many martial arts have forms that one tries to master, always falling short. Some days I practice the Tai Chi form, some days I practice the ILS. Are these so different? One friend, a straight-arrow farm boy who now captains an RJ, once remarked that he flew a lot better when he didn't let his shoulders tense up. Musicians say the same thing.

And the connection between martial arts and Chinese calligraphy go back for centuries. My friend's relaxed his shoulders before hand-flying an ILS in 1/4 mile visibility (yes, I was in the airplane), and the great calligraphers have to reach that same state in order to draw that expressive line.

The point? Flying can be an art like any other. And while we need to master the technicalities, we also need to master the art. As the current cliche goes, "right brain - left brain." Or "yin-yang." Take your pick.

Dave English uses his site hikoudo.com to explore the Zen of Flying. It's worth a look.

Guidance Counsellor

2010-09-13T22:54:00.000-07:00

Well, kids, school's starting up again and it's time to pay a little visit to the guidance counsellor. At my high school we didn't have one; it was private and academically-oriented and all of us went to college; in fact, more than half went on for advanced degrees. College guidance was handled by the Headmaster's secretary who had an uncanny ability to size us up without us noticing that she had done so. And, she provided beautiful calligraphic transcripts to support our applications. My high school transcript looks like a medieval manuscript, although I'm thankful there are no dragons in the margin.

I recently spent a day at the Eastern Idaho State Fair, working the booth for the FBO where I teach. Even during slow times you hear interesting flying questions. Being a State Fair there were a lot of "How can I become an Ag Pilot?" questions, which I answered as well as I could. There were no questions about other aviation careers, which didn't surprise me because people with Shiny Jet Syndrome don't usually like to associate with goats and chickens until they get along in their careers and realize they miss life on the farm. I take that back: one of the instructors from our other base, who is also a freight dog, talked about how satisfying he found that work, and we reminisced about some of the old freight dogs whose happiest flying days were before they took the airline job.

All of the other questions were more difficult. I ran into two kinds of pilots and pilots-to-be: people who wanted to fly for the sheer joy of it, and people who wanted to fly to support a travel bug, whether professional or personal. For example, out here in the empty part of the country a lot of medical people either fly or get flown to hold clinics in towns too small to support a full-timer. Businesses have far-flung clients, and retailers have far-flung stores. It's not Alaska but in the aviation sense you can see it from here.

So I made up the following list of pilot ``tracks." I think they all sound terrific, but many people find that one of them fits best.

Professional Pilot Corporate, Charter or Airline pilots must go through the rating sequence private, instrument, commercial, multiengine
Travelling Pilot This is the person with a far-flung business or a golf addiction, someone who has to get there as often as possible. He or she needs to be a private pilot with an instrument rating
Working Pilot This person does agricultural work, banner towing, heli-logging and the like, and needs private and commercial, but no instrument rating.
Family pilot This is someone who wants to load the family into the airplane and head out to Disneyland or the beach or the back-country. This flying requires a private pilot certificate, and an instrument rating is nice.
Fun pilot These are people like homebuilders, sightseers, and $100 hamburg addicts. They fly day VFR only, like to keep their skills up so do a lot of local flying, and maybe take one or two long cross-countries a year with a buddy. This flying requires a light sport certificate only!

Every year at the Fair I hear a lot of people say "I would love to fly but they won't let me." This refers to some medical condition that would have been grounding even a few years ago. They don't know about the Special Issuance process (which enabled me to fly a King Air after bypass surgery), and it's too expensive for what they want to do anyway. And they haven't heard the news about Light Sport flying. There is so much fun to be had without a medical certificate and with no danger to the public, as long as the Light Sport limitations are observed: two seats, day VFR, not in furtherance of a business, etc.

I've owned a light sport airplane (Taylorcraft BC12D) and fly another (Ercoupe) regularly. These airplanes are fun, and an adventurous soul with the time can do some travelling, too. I never took my T-craft to Oshkosh (although I dearly wanted to), but I did take it to Montana and to the California coast and all over Idaho and Utah. The Ercoupe is a little faster and with no pedals a little more comfortable, and the CT that I wrote about a couple of weeks ago is even faster.

The dilemma? My FBO doesn't offer any light sport flying, and I dutifully steered people toward the private pilot certificate. We'll see how many get the word.

The Source of Lift

2010-09-09T10:17:00.000-07:00

I was supposed to fly to our other campus today, as usual. The weather is low VFR to IFR with some rain, but I am instrument current and proficient. There might be a thunderstorm but the trip is so short that I am sure that I can avoid them based on preflight radar checks. There is no chance of icing.

So why did I decide to cancel the flight and drive?

Because I ran out of money.

CT Scan

2010-09-04T19:41:00.000-07:00

I showed up at the airport for my weekly commute to our other campus and found a Flight Design CT parked on the ramp. I knew right away that I would be impressed because it was parked facing in the opposite direction from everyone else, which was into the wind.

Flight Design claims a cruise speed of 115KTAS at 75% power, which means burning 5.5gph. It has a 6 hour range. This is not a toy. Better yet, it had an all-glass panel, so one could really learn to fly 21st Century style. It's certified as a Special-LSA so you can't fly it IFR, but you could still learn a lot about modern IFR flying.

The pilots -- two of them -- were delivering it from Michigan to Oregon. Despite the fancy glass, through, they had a bunch of sectional charts laid out on a table and were picking a route through the mountains of Idaho and Oregon. I offered some local advice, which turned out to be exactly what they were planning. Like I said, smart guys!

The sectional charts intrigue me, because as much as I am enjoying my new Garmin I find that I can't let go of the paper. A couple of weeks ago, I was trying to get across the Wyoming Range, and couldn't find the route I liked on the Garmin; a quick look at a sectional reminded me of the route I had used many times.

The other day I was in a similar situation (mountains between here and there) and tried the Terrain page to see if that would helped. I didn't need help; I could see my house, and I knew how to navigate back to the airport. But the only way to get to know a new tool is to use it in a situation where you know the right answer and then compare what it says to what you know.

In this case, the correspondence was good enough, but I'll still need more practice before I get to be more confident in it.

Another thing about the Garmin: I'll be flying along and get some bright idea (in other words, stupid idea) about something I would like it to do for me. So I start searching the menus for the "Airport Restaurant Tip Calculator" or some other obscure feature. This is a good time for the autopilot to be on; otherwise the heading will wander. Substantially.

But none of the airplanes I fly regularly has altitude hold. So far, every bright idea for the Garmin costs me 200 feet. That has to improve...

Prince Nymph

2010-08-31T19:51:00.001-07:00

Our annual fishing get-together in Montana is traditionally on the first Fall weekend with snow, so I was afraid when we moved it to late August. Would it really snow that early? But I confidently reserved the Archer and did some flight planning. Flight planning for this trip is silly, not because I have done it many times but because the high terrain means that there is really only one route: I-15 to US Highway 20 to US Highway 287.

Even sillier was the the AOPA Internet Flight Planner, which proposed a 2001 NM odyssey that went well into British Columbia.

Not so silly was the long term forecast. The same high terrain that makes the flight planning easy rules out any kind of IFR flight in something like an Archer. Ennis, where I was headed, has no instrument approach, and the MEA on the airway overhead is 15,000' MSL, clearly out of reach. Dillon might be an acceptable choice; the MEA there is "only" 12,000, which is within reach but leaves you no options.

So I drove. Call me chicken, but I had to had to had to be back at school on Monday, and the probability of a successful VFR flight was way too low.

Sunday saw lots of thunderstorms with hail and high winds. There was a short window when I could have made it from Dillon but that would have been at a price; the headwind was so strong that my car's gas mileage was decreased by about 10%. To the east I could see the Madison Valley, where Ennis is: the valley was blocked by thunderstorms all evening. I would have been stuck.

My reward? I caught more fish than anyone else.

Blinded by the light(ning)

2010-08-23T19:41:00.000-07:00

We got a late start, and caught between a high to our west and a low to our east we were fighting headwinds that put the groundspeed below 100. (It doesn't matter what you're in, if the groundspeed is below 100 and you're not sightseeing then you are going slow.)

The first really bad bump was the Center Weather Advisory for an area of developing thunderstorms ahead. I plotted this out; the line was thin, but extended 100 miles either side of our route. I turned toward the soft spot around Dubois (U25). I've flown that valley a gazillion times on fire patrol, so it should be easy, right? Then we'd go over Jackson Hole and then home.

But then there was lightning, and it looked like the storm would pin us onto the mountains north of Dubois. I turned southeast, paralleling the Wind River Range. Where there was no storm there was a too-high mountain, and where there was a low spot there was a storm.

Our destination was reporting 7 miles in light rain, forecasting visbility 3 - 4 miles in smoke from a 6,000 acre 20 miles south. My wife pointed out that an hour of maneuvering around this junk would cost way more than a hotel room and a nice meal.

The end result? We landed. This being the west, there was a pilot I knew in the FBO lounge, working Air Attack on a fire nearby.

"There's no way that airplane is going through that weather," I opined. He agreed.

The best part of the story? This morning, I proved that my family could be airborne at 0700.

Shut up and Fly

2010-08-18T10:44:00.000-07:00

Which Way?

2010-08-12T12:53:00.000-07:00

One of my mottos is "Sometimes you just have to fly toward the blue sky," and I have taken some monster diversions in my time. This post from UpShip! showing Airship Ventures's Zeppelin doing the same is a good reminder. You can check the flight track here.

Enjoy the closeup of the panel and the unusual instruments and terminology. Did you know that you can get training in airship flying from these folks? It's a bit too pricey for me right now, but someday...

Through A Glass, Lightly

2010-08-11T19:59:00.000-07:00

I have to admit to being a little disingenuous with my last post discussing the perils of the glass cockpit, because even as I wrote it I knew that I was planning to buy a new portable GPS to replace my beyond-aging Trimble Flightmate, whose database expired in 1995. The Flightmate worked fine as a GPS: its position, track, and groundspeed estimates were as good as any of the more more modern units, even without WAAS. But Trimble no longer supports the unit, so no database update is available. There is no moving map, although I still say that I don't need a moving map. And, worst of all, the older chip uses a lot more power than a modern chip, so battery life is poor, and the Trimble had a really clunky power cord that was always in the way.

In my mind, the position sensor is irrelevant: what we do now is database navigation, not GPS navigation. Pilots need to think about the flight as a whole, not as the next fix, and the habit of thinking a flight through will carry over into more advanced flying.

So yesterday's UPS brought me a new Garmin Aera 500 and an excuse to go flying. Knowing the perils of head-down time, I invited an advanced student to ride along, as well as my son.

The unit just blew me away, in the good sense. The yoke clip fits intuitively, with no restriction on the controls. There is only one cord, which is built in to the yoke clip (nobody has mentioned this, and I think it's a terrific idea), so the cockpit no longer resembles the floor of an Italian restaurant at the end of a long night of dropped spaghetti.

I found it easy to program, and it has all of the approach intersections, although not the full procedures (more on this later). Its terrain warning module stays in the background until there's a problem, when a window pops up with red and yellow warnings and Xs to mark where you will hit. While there are some problems with this, of which I've been aware for a long time; see my essay in RISKS 19.56, I am convinced that it still leaves us better off than we were before.

Part of my prepurchase debate with myself was the following: the cost of these units approaches the cost of used panel-mount IFR GPS, with which I could file IFR; the aera is definitely not for IFR. But an informal poll of the members of my flying club led to the conclusion that we are a VFR club. Only two other members are instrument-rated, and neither of them is current. So the improved navigation is something that I want, not the club.

The thing is, you can still use the aera to monitor an instrument approach. It doesn't do all the things that an IFR unit would do, nor is it legal even if it did. The aera will put the final approach waypoint and the missed approach point into the flight plan, but the Aeronautical Information Manual is very clear that we can only fly IFR approaches retrieved from the database. Still, if you insert the transition waypoints into the flight plan and get yourself on a segment before "loading" the approach, the fixes are all there.

I see a lot of training value in this. A student under VFR can load the approach (using almost the same keystrokes as in the panel mount Garmins) and practice, say, an area arrival. The instructor can ask the student to make the same calls (for example, "Approach Active" when 2NM from the FAWP). The student has to recognize the step-down fixes and read the chart to fly the appropriate altitude. It may not count as an RNAV approach, but the student gets the experience and will be much closer to the Escoffier standard of instrument proficiency when he or she moves up.

I think you can teach someone almost all of the ins-and-outs of a modern glass panel with the unit. I tcompares well with the various IFR GPS units I've used, and even the UNS-1 I flew in a King Air. In some ways its terrain display is more intuitive than the one in the King Air, which didn't do anything except squeek "terrain" at awkward moments unless you chose that page on the MFD.

In my case, teaching at a school with no glass cockpits and no panel mount GPSs in the trainers, this may be the only way I have to get a student to learn something about 21st century navigation.

With the Trimble, I could only teach 20th century navigation.

Through A Glass, Darkly

2010-07-29T11:59:00.000-07:00

According to the National Transportation Safety Board (NTSB), in 2006-7 the fatal accident rate for conventionally-equipped ("steam gauge") aircraft was 0.45 per 100,000 flight hours, while that for glass-paneled aircraft was 1.03 per 100,000 flight hours, more than double! [Aviation Week and Space Technology, July 26, 2010, p. 66]. The FAA and the NTSB have squabbling in their mutual genes, and the FAA says that it has done something about the problem by revising the Practical Test Standards (which detail the level of skills that pilots must show to get a new rating) and the Instrument Flying Handbook [H-8083-15A].

Of course both are right. The Instrument Flying Handbook does a great job of explaining how to use glass, but aside from instrument instructors, few pilots read it, although they should. And most pilots, even may professional pilots, forget all about the PTS once the check ride is passed. So maybe the next generation will use these tools more effectively.

The problem is with legacy pilots like me. I got my instrument rating in 1985, while EFIS was nothing but a gleam in some engineer's eye. I used VOR, ILS, DME, and ADF. I lost my instrument rating in 1993 when I became an ATP. To do that I used VOR, ILS, DME, and ADF, supplemented by a VFR-only GPS receiver that had no moving map.

Then one day I found myself going to Santa Monica (KSMO) in an EFIS-equipped King Air. The company had just bought it, and I had read the manual backwards and forwards. But between the early departure, the unfamiliarity, the pace of flying in the LA Basin, and the empty right seat, the odds were stacked against me. I programmed the route before I left, and enroute I managed to load the approach. It was a morning arrival and SMO was predictably under the marine layer. There was traffic everywhere, my airspeed was high at ATC's request, I was descending, and I was busy squinting through the haze looking for traffic and the airport. I was way behind the airplane.

But no matter; it just turned final without me.

The key to this (just barely) success story was that I had spend hundreds or even thousands of hours flying with various IFR-certified GPS units. My habit was to load an approach every time I arrived, whether IFR or VFR. "It's clear and a million!" people flying with me would chide. "It will be winter someday," I answered.

The great chef Escoffier said that one does not know how to cook a dish until one has cooked it 1,000 times.

I say that one does not know how to load an approach until one has loaded an approach 1,000 times.

The key to flying glass safely is practice and training. New pilots get it, because they are new; old timers like me need to make sure that we get it on our own. And, judging by the people at my home field who have glass cockpits, they are not doing so.

The same applies in the glider world. At a recent SSA contest, one of the contestants was selling the latest glass for sailplanes. These are complex units, incorporating the ship's performance, the terrain, and the winds aloft, and after each day's flying I saw him sitting and demonstrating what the unit he was selling could do. He was super-proficient at navigating the pages and punching the buttons.

But he landed out at least once, too.

Tanking Up

2010-07-23T09:10:00.000-07:00

Yesterday's training flight brought me a lot closer to total instrument proficiency, although I still have a way to go. My goal is perfection, a goal impossible to reach; the value is in the trying. With the medical problems both my currency and proficiency lapsed, despite some work with various Flight Training Devices (aka simulators).

I did not make things easy for myself. First, all of our club planes are tied up, so I rented a 172XP. I've flown this XP a lot, but never IFR. Unfamiliarity with avionics is a link in a lot of accident chains. In this case I said "Where is the ADF needle?" out loud, but that's the same kind of confusion you see when someone doesn't understand what, say, a Garmin 430 is showing, or how to get it to do what you want. Time spent looking for a needle in a haystack is time not spent managing the airplane. And, with no autopilot, not managing the airplane meant that my heading control was by no means perfect.

Of course it was hard to tell what my heading was: This XP's heading indicator precesses too quickly.

The airplane has no DME and I was using a handheld GPS as training substitute. Between the NOS approach book and the GPS my lap was pretty full. The polite phrase for this disorganized behavior is what the Practical Test Standards now call Single Pilot Resource Management. I'm planning to buy a new GPS, so this area will need some more work. I can use my struggle with it to help my students, especially the ones with their own planes, which tend to have every portable toy available. (The worst I ever saw was the owner of TBM-700 who, despite having every Moving Map, Primary Function Display, and Multi Function Display known to humanity installed in his panel, got lost while being vectored for an ILS.)

The wind was an issue, too, in a good way: a strong westerly flow that distorted my mostly north-south approaches, and made timing in the hold tricky (outbound groundspeed 80, inbound groundspeed 140). That's just good practice.

I flew one approach to an airport just north, planning to intercept the transition for the ILS back home. The first approach went fine, despite the spinning heading indicator and large wind correction angles, because I used the GPS "track" display to make sure that we were moving in the right direction. I started the published missed approach, and tried to tune the VOR for the transition. The NAV flag stayed visible and there was no ID, although I didn't remember seeing a NOTAM in my DUATS briefing.

It was time for plan B. I tuned the ADF to the outer marker for the ILS and headed there. This was a fine plan, except for something else that was not in my briefing. Fire season has begun, although due to El Niño and a late monsoon it is starting late. There were two heavy tankers (P-3s) and two SEATs (Single Engine Air Tankers) working the fire, and they were coming back just a little east of the localizer. I had a good safety pilot and we spotted everyone, but I have done a lot of fire fighting and know that the tanker crews are busy; holding at the marker would definitely be in their way. (I checked: there was no Temporary Flight Restriction last night, although there is one this morning.)

So now it was time for Plan C: hold at the VOR, then head out for the ILS.

You just don't get this kind of rapid decision making in any of the simulator scripts I have followed. The simulator has a lot of value, but in any case you have to fly to get the full picture

After we were done, Dan (who is not instrument rated) asked me how often I fly approaches in IMC. The answer was embarrassing: the last one was about two years ago. My medical difficulties explained a lot of this, but still...two years? I had filed IFR in that time, and flown plenty in IMC, but always got a visual approach. When I flew King Airs or freight I flew a lot of approaches, but I haven't been PIC of a King Air in a few years. My personal flying is in airplanes that cannot handle ice, so the winter is dicey at best. We tend to vacation to the east; if we took a trip to the Oregon coast there would be plenty of approaches.

Be that as it may, I am current and ready. The trick will be to keep the tank full and stay that way. I wonder if my wife would like a trip to Oregon for her birthday?

Missed Approach Fix

2010-07-09T09:03:00.000-07:00

With the explosion of RNAV approaches, which end at a "Missed Approach WayPoint", the phrase "Missed Approach Fix" has become deprecated. But yesterday's training flight brings to mind two new meanings.

Many of us think of flying as an addiction, and with my new medical certificate I have finally been able to get a "fix." Yesterday, another pilot-professor at my university and I rented a Cessna 172 and headed out for the proverbial $100 hamburgers. Actually, I chose the heart-healthier $100 turkey sandwich. Anyway, one of my great passions is instrument flight, and I needed a couple of approaches to stay current. Boy, I've sure missed my approach fix!

Training without a debrief is almost useless, so this morning I went over the approach plates to see how I'd done.

The hold at the marker and the ILS went pretty well: I blame the one-dot deviation at 400' AGL on wind shear [insert sheepish grin here]. Then I headed out for a VOR approach. I've posted the libretto to the left so you can follow along. I was a little rushed (after all, it was lunchtime and I was hungry), but intercepted the radial and flew the procedure turn as charted.

I consistently asked Dan to clear my turns. This is one of my markers for instrument proficiency and situational awareness: when a student warns me about an upcoming turn I know that she or he has enough mental capacity left over for some situational awareness. If the student is saturated, there will be no warning.

I called the tower procedure turn inbound, got established and descended to 4920' MSL way too early, so Dan got a nice view of the tree tops as we flew along. I figured that 3DME would make a good visual decent point (VDP), and things were a little busy so when I got there I took off the hood and landed.

Looking back, I completely ignored the AZAJI fix minimums! I had DME (actual DME, not a GPS!), so I could have descended to 4640' MSL! So while my approach was "legal", it wasn't efficient because I had missed a fix on the approach!

Two missed approach fixes on one flight, one positive, one negative. So the day was neutral, right? No: when I got out my log book I realized that I needed three approaches for currency.

That means I get to go flying again!

By the way, I have really learned a lot from the FltPlan.com newsletter. It highlights changes and trends in procedures for aircraft with more advanced avionics.

I Hate It When That Happens

2010-07-07T20:19:00.000-07:00

Someone on my twitter feed recommended a video on flying missed approaches, and I was all set to cut-and-paste it into the blog right here. But I watched it first and decided to reject it. The video, not the landing, that is.

Missed approach - when you get to the bottom of an instrument approach and don't see what you need to see (which, in the USA, is set out in 14CFR91.175, or, more colloquially, "THE RUNWAY") - is a tricky maneuver. From my first day as an instrument instructor I emphasized what was at stake: you are low and lost. But this does not mean that you panic: every approach ends in a missed approach, and "briefing" [airline pilot talk for "preparing"] the missed approach is part of briefing the approach. In fact, during my one-and-only-airline interview, some of the pilots in the sim check had to fly the missed approach, because they had not briefed it. A clear case of appropriate consequences for misbehaving.

With this in mind, the missed approach is not a panic maneuver. But this video recommends "cramming" the throttle forward, and the pilot's hand reaches for the flap handle much too quickly. Plus, my sensibilities are offended when someone in training utters the phrase "going missed." This is no time to sound cool; this is time to be cool, meaning disciplined, and using the proper phraseology.

What's wrong with cramming? A lot of my IFR time is in Senecas and King Airs; in either one of those, "cramming" the throttles (or power levers, as appropriate) will hurt something. Advance the power slowly and smoothly.

And the clean up? Barring engine failure, there is no hurry to reconfigure. In fact, you often have to wait. In the Seneca we typically flew the ILS indicating 120 knots, but the maximum gear retraction speed is 107. If you try to raise the gear right away, you will hurt something.

As for flaps, raising flaps induces a pitch change and, in some airplanes, causes some sink. Neither one of these is much fun when you are in the clouds down low.

So, climb to a safe altitude, then clean up.

I'm flying some practice approaches tomorrow, for the first time in a while. That is an appropriate time to cram!

[Addendum] After the original post, I checked some other videos of missed approaches on YouTube. One in a B737 simulator has the Pilot Flying calling "Flaps Up! Gear Up!" while the voice from the radio altimeter is saying "100 feet [AGL]." Now I'm not qualified in the 73, so maybe this is correct, but I doubt it. Correct me if I am wrong.

I was once a passenger on an MD-80 that had a bird strike seconds before touchdown at Oakland. The crew went around, and flew the whole visual pattern with gear down and landing flaps. Why? They were afraid of structural damage, so wisely decided to leave the airplane in a known flyable configuration.

Active 8s

2010-06-30T13:50:00.000-07:00

The authorization for my medical arrived Friday, but I couldn't see the AME [Flight Surgeon, for those overseas] until Tuesday. Success!

I could see thunderstorms moving in as I drove from his office directly to the airport. The radar showed that the cells might pass to the west. Nope, that was wishful thinking. As I took the highway exit I drove right into the gust front with it gusty winds and blowing dust that made me fear for my car's paint. Nope, not tonight.

But I went out this morning and did steep turns, lazy 8s, and a few landings. All by myself.

The turns were easy for a glider pilot, and the Lazy 8s got better as I went along. What do you do to knock the rust off?

Old Times

2010-06-24T11:23:00.000-07:00

My club washed the airplanes the other evening, and, especially when the weather is nice, airplane washing is inevitably followed by airplane drying, in other words, airplane flying. Since my medical is still in limbo I had another member ride around with me while I did some practice approaches. Even though I flew to ATP standards there was a lot of rust evident, but that's another story.

When flying an Instrument Landing System approach, it's nice to know your groundspeed so you can pick a proper descent rate. Since this was spur-of-the-moment, I did not have my GPS, and the DME readout on our Archer is a little bit, ah, flaky. How did I determine my groundspeed?

Take a look at this picture of my watch (Yes, I wear a Breitling, thanks to a generous wife!) The outer scale is a tachymeter, which is Latin for "speediness measurer thingy." You start the stopwatch and run it for one mile; at that point, the hand points to the speed made good. In the picture it's about 97 units, and in the airplane I know that the units are nautical miles. So my groundspeed was about 100.

(The principle here is the same as a ship's log: the number of seconds it takes the ship to travel its (known) length is translated into an actual speed. In ships they threw a log overboard at the bow and calibrated the knots on the rope so that each knot represented one nautical mile per hour. That's the basis of our modern terms "log" and "knot." I suppose you could do the same in an airplane by releasing a balloon and seeing how long it took to pass the balloon. This would give you a direct measure of true airspeed.)

This was the first time I had ever actually used the tachymeter in flight. In the early days of DME they were popular, because the early units only gave you distance, so it was nice to be able to determine a groundspeed quickly.

It's even nicer to be able to fly!

Attitude Check

2010-06-20T17:03:00.000-07:00

A lot of flight instructors (CFIs) give advice on Twitter (I am @DrATP, by the way), and this week a lot of it was wrong. Well, not exacly wrong, but it was not helpful.

I teach Mathematics, Computer Science, and Flying. Only the last one involves muscles and only the last one can kill you (despite how you felt in any Math class you took). I take a different approach to each subject, and think hard about how to do each one better. Here's one big rule of flight instruction that I picked up along the way and adopted quickly:

Don't teach what to do: teach how to do it.

This means something different for each student. For a presolo student, it's "Don't pull so hard." Around solo, it becomes "The nose is too high." A Commercial student might hear "You're pitching up too quickly." For an ATP it could be "V2 is 121 knots." In flying, the instructor changes to accomodate the needs of the student, not vice-versa.

(This is part of what I like about Part 61 flight instruction. At the university, or in a more-structured Part 141 program, the student changes to accomodate the needs of the instructor, who represents the needs of the program. In a structured curriculum the instructor must move on, even if some students don't understand.)

So all of a sudden I'm reading a lot of CFI tweets about flying the right airspeed in an emergency: that's telling you what to do.

I teach my students to fly the right attitude in an emergency: that's how to do it, but it's also easier and safer. And more of interest to the instructor than the student is that the lesson transfers to other parts of flying: fly attitude, not airspeed. So when I teach a multiengine student about Vyse, the proper speed for best climb performance after one engine fails, I teach him or her to fly the right attitude, not the right airspeed.

Of course it would be irresponsible of me to stop there. First of all, it's difficult to nail the attitude exactly, although usually people are too fast (which has a minimal impact on performance) rather than a little too slow (which really hurts performance). So, at some point the pilot has to fine-tune the airspeed. In the meantime, he or she has started to look for a place to land (better yet, turned toward the place they picked out before the engine failed), or even started to troubleshoot the problem.

The alternative goes like this: I fail the engine. The student raises the nose and stares at the airspeed indicator, looking for 60. When the indicator says 60 the airspeed is more like 55. "Too slow!" they think, so lower the nose until it reads 60. But by then the speed is back to 65. "Too fast!" they think. This continues ad impacto.

The hard part about instructing is seeing that what is so blankety-blank-blank obvious to you is not at all obvious to the student. This one certainly applies in Mathematics! But it applies to flying, too. We instructors need to look at things through the student's eyes, not our.

I'll close with a funny dialog between me and a student I was training in a 182. He pulled the throttle back a loooooong way on descent.

"One inch a minute, remember?" I said. This is the desired change in manifold pressure.

"I did that," he replied.

"No, that was more like five inches."

"No, I pulled it back one inch!" he insisted, and mimed the throttle travel.

And he was right: there was only one inch of throttle travel. Ever since then, I tell pilots "One inch of manifold pressure a minute." You get the idea, I hope.

Making Mountains out of Molehills

2010-06-17T09:24:00.000-07:00

I hate personal whining in blogs, but allow me to say briefly that the FAA "has done a lot of work" on my medical; I might hear something as soon as next week.

In the meantime I have gone to work resurrecting and redesigning a mountain flying course that I used to give. I created it for retail customers, and later made it part of the single-engine 135 syllabus. The new-hire charter pilots usually had about 600 hours and were active instructors, so they were sharp on the CFI stuff like short field landings and steep turns, but weren't ready for flying the fire patrols and Fish and Game flights that were the source of the single engine charters. So we reviewed mountain flying techniques ("Always be in a position where you can turn toward lower terrain"), then headed to the airplanes (182s).

The flying part was fun, and eye-opening. I would fly them into a bowl (there was a nice one within 10 miles of our home airport), and have them pick an escape heading; that would be where the terrain was most manageable. Mountain flying is like a pact with the Devil, and like "Shoeless" Joe Boyd in Damn Yankees you always need to have an escape clause in the contract.

We'd fly around the bowl for a while, admiring the scenery. Then "Put on the hood."

"What?" They all said that.

"Put on the hood."

And so they did.

Then came the eye-opening part. I hoped that they would immediately climb and turn toward the escape heading, but no pilot I ever trained did both, and many did neither. They just flew along, holding heading and altitude, as if all of a sudden this had become an instrument lesson. I would let the mountain get really big in the windshield, then have them take off the hood.

It was like the reveal in Trading Spaces. "Oh my God!" they all said, even the most devout non-swearers.

"That's why you pick an escape heading," I would say, and then we would go on to the next exercise.

Oh, the Humanity!

2010-06-13T14:27:00.000-07:00

The day after the Hindenburg accident, the Boston Globe ran a small story under the head "18 Major Dirigible Disasters Have Marked Last 23 Years." The list included the 1935 crash of the Macon (the site was recently added to the National Register of Historic Places), the 1930 crash of the R-101, and so forth, the first being the 1912 crash of the Akron.

And while the latest disaster involves no bodily harm, I was saddened to read on the airships.net blog that the Nippon Airship Corporation had ceased operations. Their website returns a bogus 403 error (it's actually their webpage, not a server response). I can't find any news about what will happen to the ship (NT Serial Number 2).

RIP

Manifest Destiny

2010-06-11T21:32:00.000-07:00

Family vacations these days mean lots of 737 time, in the back. And since the FAA seems to be in no particular hurry to grant me a medical certificate (150+ pages of "normal" evidently not being enough), and since we do not have any soaring weather predicted until next week, 737 time is all I'm going to get.

My daughter is a little bit of an airplane nerd. As we settled in for the first leg, she asked "How much does the airplane weight right now?" What a great question from a 7th grader!

"Oh, I don't know, maybe 120,000 pounds. We'll ask in the cockpit after we land."

So we settled in with our books and iPods and watched the scenery go by. For the life of me I can't explain why before an airline trip I go to Flight Aware and get our clearance (I do it on my iPhone, and take a screen capture of yesterday's route), so I sometimes look out the window and pretend to navigate. Back in the VOR days (Doesn't that make me sound old? How about "Back in the days of the four-course range..."?) you might actually spot a VOR, but now we pass RNAV waypoints like KAADE that are really defined as x-, y-, and z-coordinates in an Earth Centered-Earth Fixed coordinate system.

As we filed out of the 737 she got shy so I went to the cockpit by myself. Only the FO remained.

"Do you happen to remember our takeoff weight? My daughter, who is getting shy, wanted to know. And I had a guess."

"What was your guess?"

"About 120."

"Not bad." He started to go through the little bag of trash that airline pilots always manage to leave behind. "Here, here's our loading schedule. It was 125,658 pounds. You should have bet her!"

He handed me the loading schedule. "Keep it," he said, "And, oh, here's our dispatch, keep that, too."

During my days flying Part 135 I was a perhaps too much of a stickler for paperwork. "Pilots get busted for paperwork," I told everyone, "so protect yourself." Our systems were manual and more than cumbersome. You had to get the aircraft configuration out of the maintenance log, enter that onto the manifest, read off the empty weight and empty moment, and then start the weight-and-balance calculation. If the maintenance log didn't agree with the manifest, the FAA could bust you. If you were over maximum zero fuel weight, the FAA could bust you. If your listed takeoff time happened to be a time when the field was below minimums (another complex calculation), the FAA could bust you. As check airman I made sure that everyone did this all correctly, once, but who knew what happened when I wasn't watching?

I kept trying to design new forms that pilots would actually use. There was a "Life Flight Shift Briefing" form, which summarized weather at our typical destinations, MEL items, and the like. Looking at it now (I changed the names to protect the innocent) it seems rather simple. But nobody used it. Nor did they use the passenger briefing cards, flight planning forms, duty time calculators, altitude optimizers, or any of the other stuff.

(To make up for this, I did a monthly newsletter with the subtitle All flying, no paperwork that covered emergencies, weather, and other techniques. People read that one. It was the precursor to this blog.)

This airline gave the pilots everything I would have wanted. ICAO and FAA flight plans. Mode S transponder code. Minimum Equipment List items. Fuel planning. Takeoff and landing data. A navigation log, just like the ones you did as a student pilot. Information comparing terrain to service ceiling. Plus company contact information and company NOTAMs.

A person could get used to flying that way. Even if it is from somewhere in the back.

NextGen, GPS-style

2010-05-27T22:31:00.000-07:00

No, not the FAA's NextGen, but the GPS system. A Delta IV rocket took the first of the "Block IIf" satellites into orbit today, after several aborts (including one atT-minus-6 seconds) and delays. The new satellite will transmit on the L5 frequency. This satellite is a completely different design from SVN49, and one hopes that there was more testing. According to the US Air Force, it will take 3 - 4 months before the satellite is marked "healthy."

There are more than enough birds on orbit, but as I mentioned last week they do have a finite lifetime.

SVN49 and Old Possum's Book of Practical Cats

2010-05-21T21:16:00.000-07:00

I've been trying to piece together the story of SVN49. What's SVN49? Is it one of those unpronounceable high-altitude fixes that Center uses to steer you around uncharted military airspace (those of you who fly in the flight levels in the west know what I mean)? Or an oceanic fix? A proposed regulation? SVN49 won't affect me in my Cherokee Six or glider, right?

Wrong. SVN49 is a GPS satellite. Everyone in the world uses GPS, if not for navigation then for timing, so everyone should be worried.

Why haven't you heard of SVN49? A GPS satellite is like a cat. T. S. Eliot wrote

The Naming of Cats is a difficult matter,
It isn't just one of your holiday games;
You may think at first I'm as mad as a hatter
When I tell you, a cat must have THREE DIFFERENT NAMES.

We can counter with

The Naming of Sats is a difficult matter,
It just isn't one of those rocket nerd games;
You may think that these geeks are as mad as a hatter
When they claim a sat must have THREE DIFFERENT NAMES.

Obviously one of the names is SVN49; SVN stands for space vehicle number. The second name is NAVSTAR 63; NAVSTAR was the original name of the GPS program. And the final name, the one that belongs to "no other sat," is PRN01.

PRN01 should ring a bell; you've probably seen NOTAMs like

!GPS 12/064 GPS NAV PRN 25 OTS WEF 0912181500

Aviation GPS receivers usually refer to satellites by their PRN. PRN stands for Pseudo-Random Noise, and is one of the engineering marvels of the GPS system. The original GPS system had all of the satellites communicating simultaneously on two frequencies, called L1 (1575.42 MHz) and L2 (1227.60 MHz). You've heard the mess that results when two airplanes transmit on the same frequency: lots of noise followed by someone saying "Blocked." But that's the standard GPS communications environment.

The receiver gets the navigation data from one satellite at a time using CDMA (Code Division Multiple Access), which is also called spread spectrum encoding. Many cellphones use the same technique to allow simultaneous conversations on the same frequency. The technique was invented by, and patented by, the actress Hedy Lamarr during World War II. Her patent expired before the advent of GPS, so while her estate gets no royalties her name is revered in GPS circles. PRN01 refers to the specific binary code assigned to good old NAVSTAR 63.

SVN25, or PRN25, is out of service for a very good reason: it was launched in 1992, and has given its all for the cause. Much like the LGU VOR, which has been off the air for years and years, the satellite lives on in the NOTAM telling us not to use it. RIP. SVN49, however, is still begging at the door to be let in. It has been assigned PRN01, so we can tell its signals from all other signals, but its status is ominously unhealthy, so your receiver ignores it.

We all know that the FAA NOTAM system is a mess, but that's not the only NOTAM system involved. The US Coast Guard Navigation Center publishes NANU's. NANU sounds like something that Robin Williams said on Mork and Mindy, but in fact it is quite serious. NANU stands for Notice Advisory to Navstar (you remember Navstar, right?) Users, and this is where DUATS and Flight Service get their GPS NOTAMs. Here's the deal on SVN49:

!NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2010068 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
THE 50TH SPACE WING IN COOPERATION WITH THE GLOBAL POSITIONING SYSTEMS WING, WILL BE TESTING SVN49 (PRN01) SIGNAL CHARACTERIZATION OVER THE NEXT 6 MONTHS. SVN49 (PRN01) WILL REMAIN UNHEALTHY UNTIL FURTHER NOTICE, AND THE BROADCAST NAVIGATION MESSAGE WILL REMAIN IS-GPS-200 COMPLIANT. USERS CHOOSING TO TRACK AN UNHEALTHY SVN49 (PRN01) SHOULD CONTACT GPSOC (MILITARY) OR NAVCEN (CIVIL) IMMEDIATELY FOR ANY ISSUES THAT MAY BE ATTRIBUTED TO THESE ACTIVITIES.

How SVN49 got to be unhealthy for 15 months is a cautionary tale about engineering. The first thing to keep in mind about engineering is that at some point you have to freeze the design and start building: that's version 1. But even while you build version 1, you think of improvements, which eventually make their way into version 2. Etc.

One of the improvements to GPS is the addition of a third frequency, L5 (1176.45 MHz). This will give users improved correction for transmission errors, but the choice of this frequency is controversial.

In any event you have to test, so Lockheed-Martin engineers took a spare L5 transmitter and bolted it to a spare power bus on SVN49. Nobody has explained why a satellite has a spare bus, which is a lot more complex than having a spare USB port on your computer, but that is the case.

Now this was not a willy-nilly fly-by-night operation: I have no doubt that LMCO engineers did all of the requisite analysis, and that the proper drawings and other documentation were made. (It's very important to document every little detail of a satellite; imagine your embarrassment when the thing gets to orbit and doesn't work and you don't really know what you did when you built it.)

But despite this due diligence, the L5 signal interferes with the L1 and L2 signals, and the navigational data from the satellite is, so far, unusable.

Now there's more than one way to skin a cat, and lots of people are putting lots of work into figuring out how to make SVN49 useful. For the moment, though, it's still begging at the door, waiting to be let in. Let's hope that soon it will be PRNg.

Falcons

2010-05-15T18:01:00.000-07:00

The Falcon jets from Dassault are beautiful airplanes, as I've mentioned before. Alas, I have yet to fly one.

People have mixed reactions, to them, though. The April issue of Professional Pilot, for example, poked some fun at them last month in their "Sid and Star" cartoon. Pro Pilot is a narrowly-aimed magazine with a focus on business aviation; it's free, but if you don't already get it you probably wouldn't enjoy it, because they send it to just about everyone who would. Sid and Star are a pair of hard-working pilots who fly a "Howler" for Lugnut Industries. Pro Pilot naturally has the point of view that business airplanes are far from luxuries, and while I generally agree with them, I have seen some abuses. In this case, a sales rep from "Dijon Aero" has come by to demonstrate the "Cameo 3X" and its luxurious appointments. In gratitude Lugnut takes the sales rep to his favorite local dive for a meatball sandwich. Aghast, the Dijon sales rep recommends against selling a Cameo to Lugnut. The strip is a nice concise argument against the idea that business jets are a luxury, at the expense of the French (it's easy to mock the French; just ask Disney).

Despite this, Dassault still has an ad for the Falcon 2000LX on the back cover.

By contrast, May's Business and Commercial Aviation's 20/Twenty column features the Falcon 900, praising its fuel efficiency and handling, and noting the continuous improvements over the aircraft's 24 year production run. They call the airplane a "well-defined work-a-day example of transport art and technology."

But whether the airplane is luxurious or work-a-day is an issue with the back of the airplane, and I'm more interested in the front. so Let's turn to the may 3, 2010 issue of Aviation Week and Space Technology. The cover is a beautiful photograph of the 7X, with the familiar three engine configuration of the Falcon 900, flying away from the setting sun over the ocean. The airplane's elegant shape and smooth construction are highlighted by the swell in the ocean below.

AW&ST generally takes a neutral view, so their pilot report on the 7X is neutral in tone. The 7X's big innovation is its fly-by-wire control system, based on Dassault's success with the Rafale fighter.

The mathematician in me marvels at the progress that these systems have made, and while a little part of me whines about the need for perfect redundancy, Dassault is claiming 10^(-10) (yes, that's 9 zeroes between the decimal point and the one) reliability, so maybe I am beginning to soften a little. That's probably better than an Archer, and definitely better than a Seneca (Senecas came out of the sky in little pieces for a while due to an anomaly in the rudder trim system).

The glider pilot (yes, the glider pilot) in me admires how the sophisticated stability augmentation from the control system enabled Dassault to reduce the size of the empennage by 20%, cutting a ton of drag (approximately). I've flown draggy airplanes like King Airs and 182s, and sleek airplanes like Mooneys and gliders. The sleek ones are more fun!

The working pilot in me admires all of the labor-saving that fly-by-wire provides. Even more primitive flight control systems are a big help in this regard. I remember a busy early-morning arrival in Santa Monica in an EFIS King Air. Early morning arrivals in Santa Monica mean oh-dark-thirty departures from Idaho, and I was zonked and busy. Something distracted me and I was head-down for a little longer than I care to admit, and when I looked up, the airplane was turning final all by itself. I might get behind, but the Flight Management System stayed ahead.

The Falcon 7X's EFIS displays feature a Flight Path Symbol (FPS); we used to call it the velocity vector. These have been around in Heads Up Displays (HUDs) for a long time. I've never flown with one outside of simulations, but they make flying incredibly easy. You put the velocity vector (the circle with the little gull wings below) on the horizon and, by golly, you fly level. (The picture at the right is from the fabulous X-Plane App for the iPhone, which is well worth the $10 they charge.)

But the stick-and-rudder pilot in me is infuriated. Or worse! You never actually fly this airplane! Instead, the flight control system interprets sidestick inputs as requests to manipulate the flight path vector. Then the stability system takes over and keeps the FPS (and, with it, the flight path) where you put it. You never have to engage the autopilot, because in effect the autopilot is effectively ON as soon as the Built-In Tests are complete.

The sidestick is nothing more than an ergonomic and intuitive autopilot head. Sacré Bleu! I believe in autopilots but this has gone too far.

So I approach the airplane with mixed feelings. It's fast, it's efficient, it's beautiful, it's useful, and apparently its controls feel great. But if I ever win the lottery I think I'll opt for a nice 900 and a congenial copilot with good hands.

May 6

2010-05-06T10:40:00.000-07:00

It's fun to think about what happened in aviation on any particular date, but I'm not sure it's fun enough to devote a whole blog to. So why is May 6 special? For me there are two reasons, one obviously personal and one becoming more so.

The personal reason is that I used to own Taylorcraft 9114 (N95814), which was built on this date in 1946. Taylorcraft was building 40 aircraft a day at that time, but went out of business by the end of the year. The T-cart was my vehicle for endless hours of fun, not all of them in the air. I sold it because I had to. They say that the average American family is one illness away from losing its house; in my case, I guess I was one illness away from losing my airplane. But I did sell at a substantial profit!

The emerging personal reason goes back to this post from September, 2008, when my daughter presented me with a gift of old postcards of Boston, where I grew up. One of them showed the airship LZ-129 Hindenburg over the city, and sense then I have spent a fair amount of time researching the great (and, frankly, not-so-great) airships. Someday I hope to write a book about them. The world needs an airship book that both underplays the Hindenburg accident and highlights the arrogance between the crash of the R-101.

Usually what I do is devote a day or so after the end of the semester to airship research. Sometimes this means going to libraries and studying newspaper microfilms, and sometimes it means surfing the 'net. And since I am giving my last final exam of the semester right now, I spent the usually pointless proctoring time (it's a Computer Science exam and it's open book, so really what am I protecting against?) surfing the 'net.

And May 6? May 6, 1937 is the date of the Hindenburg's crash at Lakehurst, an appropriate day to devote to its study. Especially since it is snowing here in Pocatello.

I will spare you any of the clichéd references to Herb Morrison of WLS and the iconic overused pictures of the fire. If you really want to watch what happened, see Howard Hughes' brilliant movie Hell's Angels. Not only will you get to hear Jean Harlow (a figure even more tragic than the Hindenburg) offer to change into something more comfortable, you'll see a harrowing scene of a Zeppelin fire that is eerily prescient of the Lakehurst accident.

The book I have in mind is really an engineering and transportation history of the era. I'm also very interested in the liner Queen Mary, which was formerly housed with Howard Hughes's Spruce Goose in Long Beach. It's maiden sailing bracketed the Hindenburg's "Millionaire's Flight" of October, 1936. And I suspect that, with her speed and easy access to Manhattan, the Queen Mary could beat the Hindenburg in a door-to-door race from Frankfurt to the Empire State Building. Of course neither could match the 777...

I would also discuss the decorative aspects of both ships; both featured fabulous Art Deco and International Style decor.

And of course I would also need to understand how they operate. Alas, the Queen Mary's boilers have been removed, but the bridge is intact, and I have spent enough time in the engine room to convince myself that I could get her moving. (Isn't fantasy fun?) But flying an airship is no fantasy: Airship Ventures has a Zeppelin on the West Coast of the US, and they offer training.

There are two obstacles, though: first, it's expensive, but I have been saving my pennies. (When the German government refused to support the construction of the Graf Zeppelin, lots of people made small contributions to fund the construction. Maybe I can get lots of small contributions to fund flying one of its successors?) Second: training requires a valid medical certificate. And since mine is "in line for review" according to the FAA, I am going to have to wait.

Maybe I can do it next year on May 6.

Jimmy on the SPOT

2010-05-04T21:03:00.000-07:00

The more soaring I do the less it seems like flying. Now that's nonsense, because while you are soaring you are definitely surrounded by air. I have the same feeling about ag flying, too: yes, there is an airplane, but the flying seems secondary to the mission. Maybe the way to look at it is to that flying is such a large part of my outlook on the world that I spend more time looking at how things are different than how things are similar.

Or think of it this way. A couple of years ago I went to the Soaring Society of America convention. This was one of those typical soaring productions, involving dozens of phone calls and emails and several weeks of deciding the best way for all of us to get from Salt Lake City to Albuquerque. We're all pilots, and some of us are power pilots, so there was a lot of comparing my club's Cherokee Six to Lew's Bonanza and Tim's Mooney as far as comfort, performance, and cost. The Mooney lost on comfort. (Keep in mind that I am a former Mooney owner, but a couple of the guys are pretty big and it's hard to fit big and Mooney into the same sentence.) And in the end the Bonanza and the Six lost out to Southwest's inexpensive 737, which is certified for flight into known icing.

We arrived separately, but we all left on the same flight. So here we are, 6 or so pilots filing onto an airplane. I know a bunch of Southwest pilots and believe me, they are pilots just like we are. (If you doubt me, watch the crew exchange in the jetway: you'll see lots of hands in the air illustrating the finer points of landing on 7R at Las Vegas when the wind is out of the south.) But what they do, at least when they are at work, seems to have nothing in common with what we do. (And, again, this is nonsense, since lots of airline pilots are glider pilots, like Dave English from hikoudo.com, or Lew with the Bonanza, and even I am getting ready to do some King Air instruction later this summer.)

So maybe flying is flying.

But something is different about soaring. I was reminded of this yesterday as Tim (of the Mooney) set out to fly 1000km in his Ventus, a high performance single seater. He had been watching the weather for a few days (and, yes, this involved dozens of phone calls and emails; we are like a bunch of old ladies) and it looked good.

He launched at about 0800 local time, a time more typical of a King Air than of a glider, but the forecast was for strong west winds which would mean lots of ridge lift. He set his SPOT to track mode, and as soon as the first track message got out there was a flurry of emails.

School is still in session for me, so I was stuck in the office or, at best at the coffee shop. I checked Tim's progress through the morning, noting that he made his planned turn near Salt Lake City and was headed north. I told people about the attempt, and of course many of them looked at me funny. But I was excited for him. And jealous, of course.

Headed out for lunch I checked his progress. But now there was something different: instead of a "track" message, his SPOT was sending a "help" message. He had landed out. (SPOT has two help messages, the "I'm OK but need help" kind and the "Call 911!" kind. Tim's was the former.)

Or so it appeared. I tried to call him, and got no answer: the advantage of SPOT is that it works where cell phones won't. So I left a message and sent a text "saw your help msg what do you need?" Sometimes an SMS message gets through even when cell coverage is too weak for voice.

The old lady glider pilots started to light up the phone and T1 lines with talk and email. I was physically closest to Tim but nowhere near his trailer, but I started to head his way just in case. But before I got to my car, Tim called. He had hiked to get cell phone coverage, and as soon as he got it there was my text.

What a world! There you are, alone in a single-seat aircraft, in a sparsely settled valley, in a plowed field, almost as alone as Apollo XI astronaut Michael Collins on the back side of the Moon while Neil and Buzz explored the surface. But no, that's not right: your friends know where you are and before you can even ask for help it is on the way!

But that's one way soaring is like flying. We go out of our way to help each other out. I've had airliners relay messages to Center for me, and I have relayed messages to airliners, including whole IFR clearances. That's another story; or is it? The FO was a friend, we recognized each other's voices, and they couldn't reach ATC, and the next thing I knew I was saying "ATC clears Skywest blah-blah-blah to the ..."

I could have saved him from copying the clearance if I had thought to send him a text.

Our Place in the Sun

2010-04-22T20:23:00.000-07:00

I was standing on the ramp in Logan, waiting for my buddies Brad and Kim to come back in the club Blanik so I could fly. The Sun felt good but being on the ramp waiting to fly felt better. I knew I was strong enough to fly because I had done 10 pushups that morning, the first pushups I could manage since being hit by rheumatoid arthritis.

And there they were, crossing at midfield. I took out my phone and tried to take a picture, tracking the glider manually as it passed straight overhead. The Sun got into the frame and you can see the result. But the Sun felt good and so did being on the ramp waiting to fly.

Trippin' the Light (Sport) Fantastic

2010-03-25T13:21:00.000-07:00

My medical recertification is palpably closer; I've already started the preparation (which mostly means no caffeine, so I ate some chocolate with breakfast) for tomorrow's treadmill test. Then comes the angiogram, the bundling of the reports, and off it all goes to Oklahoma City for the FAA docs to consider. I can't run anymore due to rheumatoid arthritis, but I have been walking and biking, so I'm pretty confident.

But being confident won't remove one hole in my certification: I need a 14CFR61.56 Flight Review, usually called a BFR. We're supposed to get the review very two years, but, as one of my instructors used to say, "there are a lot of ways to skin that cat," and for the past fifteen years or so I have either added a rating or passed a 14CFR135.293 pilot proficiency check.

(Another method is to do something with the FAA's WINGS program, but there are two problems with this. First, the redesign of the WINGS program has made it awkward and confusing, to say the least. The other problem is that WINGS, at least in its previous form, demanded experience but no proficiency. I have seen pilots complete the WINGS program whom I would not have signed off for a BFR.)

After all of the "automatic" BFRs it was hard to remember what to do, but I had a plan. Richard Neves, a local instructor, has a 1946 Ercoupe, and has been flying its wheel pants off giving Light Sport instructions. It's a pretty airplane, and I have been looking for an excuse to fly it. What better excuse than a BFR?

So I called Richard and told him I needed a BFR. There was a little serendipity: he needed one, too. So we could trade.

Another exception to the BFR regulation is that current Flight Instructors are not required to have any ground instruction during the flight review. The idea is that instructor recertification, required every two years, makes the review superfluous. I don't agree: bad habits can form pretty quickly. In our case, I needed instruction on Ercoupe systems, so I got an hour's ground while observing Richard's teaching style and knowledge of systems and regulations. Sounds like a pair of good BFRs to me.

The 'coupe has no flaps and giant ailerons, about 3/4 of the span. And, originally, the ailerons and rudder were connected, so it is always coordinated. Some owners have added rudder pedals, but Richard's still has the single brake pedal on an otherwise smooth cockpit floor.

Then we flew. Having no rudder pedals is a big adjustment. It took a while to get the hang of steering with my hands while taxiing, but that was minor compared to my big error: when Richard pulled the engine on me (right after doing lots of stalls, such a classic flight instructor move), I picked a nice field right below us, tried to restart, and approached high, thinking that I could slip it in! Oops! You can't slip without rudder pedals!

We did a ton of landings, trading off on the controls. He showed me how to do a steep power off approach; the 'coupe is brick with the engine idling, so those work out well.

After two hours of stalls, steep turns, engine failures, crosswind landings, and chit-chat about the state of aviation we signed each other off and called it a day.

I was surprised and disappointed to hear Richard say that I was the only local instructor who was embracing light sport flying. Perhaps my medical woes have made me more open-minded, but my interest in LSA is more than selfish. I want to jam my family into the Cherokee Six and fly off on vacation, night and IFR if necessary, and that's not possible with light sport privileges. But I also want to take my friends and families for hops in the Ercoupe. It is easy to fly, it has an intriguing funky air about it, and it has a big glass canopy, meaning almost as much sight-seeing as in a glider or fighter. It's both the past and future of flying. Thinking back most of my private pilot students were really interested in light sport privileges: day VFR, two seats, going-to-visit-your-cousin-in-Twin Falls flying. This is a way to get more people into flying, and it has to be good for all of us.

When the medical comes, and with it light sport privileges, the Ercoupe gives me a new recruiting tool. No, that's incorrect, that's corporate language, so I take it back. The Ercoupe gives me a new way to help people have fun "messing about in small planes," to quote Richard Collins paraphrasing The Wind in the Willows. And fun is what it's all about.

A Modest Proposal

2010-03-14T21:12:00.000-07:00

I'm approaching the end of my six month wait for recertification after last September's angioplasty; my testing is scheduled for days n+2 and n+4, where n is the FAA requirement.

Getting ready to fly again has got me thinking about what I did not, or, better, could not do as an instructor without a medical certificate. In particular, the combination of 14CFR 61.23(a)(3)(v), "Medical Certificates: Requirement and Duration," and 14CFR91.107(b)(1), "...Simulated Instrument Flight..." require that an instrument instructor (CFII) have a third-class medical certificate; the latter makes the instructor a required crewmember, and the former says that an instructor who acts as a required crew member must have the medical.

Generally, the reason that medical certificates are required is the concern that a crewmember suffer from "sudden incapacitation." That means things like heart attack, seizure, stroke, or kidney stone. I imagine that it is a truth universally acknowledged that sudden incapacitation in an aircraft is a Bad Thing.

The secondary reasons that medical certificates are required is the concern about vision and hearing. You can't see and avoid other aircraft if you can't see. (You can fly well if you are deaf, but the FAA makes you prove it and limits your privileges with regard to radio use.)

The justification for 14CFR 61.23(a)(3)(v) is based on the secondary reasons. A CFII having a heart attack while a student is under the hood is no different from any other passenger's incapacitation, and we have no medical requirements for passengers. Sudden incapacitation of a passenger is a Bad Thing, and pilots need to be prepared to deal with it, but it is not a threat to the public at large.

No, the reason a CFII needs a medical is to make sure that he or she can "see and avoid" other aircraft and the ground. That's why we have 14CFR91.107(b)(1).

Now, in the past few years the FAA has decided to accept the judgment of another agency about pilot vision: your state's Department of Motor Vehicles. If you have a driver's license and your most recent medical was not revoked then you may exercise "Light Sport" privileges. Light Sport privileges are restrictive (day VFR, ground contact, altitude and speed limitations, and, most importantly, number of passengers). But it is my experience that a large amount of instrument instruction more-or-less fits the Light Sport model. The airplanes are heavier and faster, of course, but the back seat is empty and it's day VFR.

So here is my proposal: allow a CFII who has Light Sport privileges to fly with a student under the hood. I see no downside; if you do, I would like to hear it. The upside is that this would allow a bunch of older, experienced instrument instructors to continue to pass their wisdom along to the next generation without worrying about a medical certificate.

There is one big difficulty here. 14CFR61.65(d)(2) requires a training flight that is conducted under instrument flight rules. I like this regulation; it makes sure that students get out into the system. And I do not think that someone with only Sport Pilot privileges should be PIC under IFR; if the CFII became incapacitated in instrument conditions while approaching a busy terminal, there would be a lot of trouble. But a CFII without a medical could send a student to someone with a medical for this flight, which would make a very comprehensive stage check.

So, what do you think? I plan to contact the FAA to see what they think. Let's keep all that knowledge and experience around for the next generation.

Against the Current

2010-02-09T18:46:00.000-08:00

When you don't fly professionally (or, worse, when you don't have a medical certificate) it's important to take advantage of every opportunity. Looking at this morning's forecast of nothing better than 600 overcast, I figured that today would provide none. So I cheerfully went to class, then across campus to lunch, talking with a visitor from Spain. I couldn't help but notice that the university weather was a lot better than 600 overcast, but sometimes the city is in the clear while the airport is in the soup, so I once again dismissed the thought that kept interfering with what should have been my mathematical frame of mind. I settled into my office chair. I couldn't help myself: I logged onto DUATS and got a weather briefing. "Just for practice," I told myself, "just for practice."

Maybe practice makes perfect: the metar was KPIH 092353Z 03007KT 10SM SCT048 00/M06 A2998. How much research did I need to get done this afternoon, anyway? Hadn't I put two new theorems in my notebook just yesterday?

But it's not so simple when you don't have a medical certificate. I started phoning pilots. Greg was already at the airport and ready to fly. It's time to fly!

Greg and I have flown a lot together (I instructed him for his CFI), so settled into our personal patterns easily. One thing about flying with Greg keeps me at the top of my game. Greg used to be a controller. When there's traffic, he sees it before anyone. Better yet, he knows how to point it out, so when he says "There he is, 3 o'clock, down low," you look and find it right away, too.

And there was lots of traffic on this pretty afternoon. We went to Blackfoot for a touch-and-go, departing just as a flight of three high-wing taildraggers arrived, about 200 feet in trail from each other. Someone kept calling them "party of three" on the radio, as if it were a restaurant.

Heading home, the Worst Controller I Know was working the tower. "Uh-oh," we said, almost simultaneously, "this should be interesting." I wanted to fly a practice ILS, but there was another airplane already on the approach. Well, it was not exactly on the approach, it was outbound to the marker. So maybe Mike (it's a small town, we know who's flying what) was 6 miles from the marker, outbound, while we were 6 miles from the marker, inbound. By the time Mike got there and started outbound for the procedure turn we would be in the hangar. Somebody was swimming against the current, and it wasn't Mike, and it wasn't me.

But the controller didn't see it that way. So I did a 360 (under the hood), and when I rolled out there went the outbound 182, 1000' above us, headed away from the airport.

Somehow I got the controller to see that we were in front of the 182, where we had been all along, so we did the approach. The controller kept micromanaging, though, and his frequent irrelevant radio calls threw me a dot off. Grrrr. Greg was laughing loudly, but was also careful not to key the mic while he did so.

Done with the ILS, we were in closed traffic. A Falcon called, on the GPS approach. "This ought to be fun," Greg said, and I agreed. Four VFR airplanes was over this controller's personal minimums. I thought about calling the tower chief on his cell phone...

The frequency was busy and The Controller kept changing his mind about the landing sequence. I didn't help. He put us ahead of Mike in the 182, but I knew Mike needed to do a circling approach, so I volunteered to extend my downwind to let Mike finish. But meantime the Falcon was arriving, probably indicating 170 or so.

"There he is," Greg said, and sure enough I followed his eye to the Falcon. The eyesight pressure was on.

"Looks like a 900," I said.

"Yeah, beautiful airplane," he said, not missing a beat. Of course he was right.

So I didn't just get to fly. I got to be bury, mixing it up with The Controller and watching my spacing from other traffic and even avoiding a bird strike. the kind of flying that keeps you sharp. I hope. At the end of all this, I was surprised to note that I am instrument current until the end of March. Without a medical certificate it won't do much good, of course, but it will be nice to be ready.

LORAN

2010-01-14T13:43:00.000-08:00

I already commented on the decommissioning of LORAN-C at N631S. In addition, here are two excerpts from my book, Understanding Mathematics for Aircraft Navigation.

p. xiv [A World War II story from my father]: "...enroute to tiny Eniwetok, they were unable to make celestial sights due to weather. He and another officer decided to try the ship's LORAN. The LORAN worked and gave them an indication of their position, but the captain refused to believe it."

p. 168 "[they] might have been more successful if they had used the LORAN in their daily navigational chores, rather than waiting until a crisis. The accumulated experience might have tempered the captain's skepticism. Conversely, older methods that aren't used at every opportunity become rusty and unreliable, especially in an emergency."

Someone once noted that a large number of navigators have been replaced by a small number of engineers. The engineers have made our navigational lives immeasurably easier. But shit happens, so it is important to practice the basics. I don't mean that you have to torture yourself and turn off all of your avionics; looking at a chart and keeping a navigation log keeps your dead reckoning and piloting skills current.

Instead of playing my "old man" card and bemoaning the decommissioning of the last CONSOLAN station within my lifetime (it was on Nantucket), here's something more positive, an essay from the National Air & Space Museum blog on the remnants of the lighted airway system, and some chart scans that show the beacons. I'm ashamed to say that I have never navigated by these beacons, despite a lot of Montana flying. I missed out on the four-course range and CONSOLAN and DECCA and OMEGA-VLF, so I should get myself back up there and see for myself.

Of course I want LORAN to stay, even if it goes, remember:
back yourself up; fly safely!

Heat on Pitot Tubes

2010-01-07T13:23:00.001-08:00

There's an article about pitot tubes in the current (January 6, 2009) issue of Aviation Week and Space Technology. We start to learn about pitot tubes during Flight Lesson One. Learning about pitot tubes changed my academic career, at least a little: in pure Mathematics, we don't need instruments, and we certainly don't learn that instruments need to calibrated.

Like any instrument, a pitot tube is designed to work under specific conditions. AF447, which crashed into the Atlantic Ocean last year, had pitot tubes that were certified to handle temperatures as low as -40C, although it is not unusual for turbine airplanes to fly in colder air. For example, the King Airs I flew were limited to outside air temperatures above -53.9C; certification down to -40C is not enough. Now, some are calling for pitot tube certification down to -70C, because temperatures that low occur in the very high thunderstorms of the Intertropical Convergence Zone. Nobody seems to know what shapes ice crystals take at those temperatures, and, besides, it's hard to keep something warm when the ambient temperature is that cold.

The scandal is that this deficiency was first identified in the mid-1990s, but the airplanes still have inadequate pitot tubes.

I am reluctant to confess that I have never had a good attitude toward pitot heat. That overstates the case, because my attitude is consistent with whatever airplane I'm in. In something like an Archer, that is, a single without deicing equipment, I don't think about pitot heat much, because I am going to work like crazy to stay out of any icing conditions. (The few times I've had airplanes like this in the ice I turned the pitot heat on.)

The first airplane I flew that could handle ice was the Piper Seneca II. We had four of them, flying three scheduled night IFR routes in Idaho and Utah, and I was the check airman. We all knew that the pitot heat didn't work well, and expected it. You would be flying along at 25" manifold pressure (which was good for about 130 KIAS in level flight at our altitude), but the airspeed needle would hover around 60 or 70. We joked about it, but as check airman I made sure that everyone knew the target power settings for each maneuver. When the airspeed indicator failed you were pretty sure that you could put the gear down as long as you were flying level at the right power setting.

This kind of thinking might have helped the crew of Birgenair 301 in 1996. The airplane left Puerta Plata, Dominican Republic, at night. Their's was not a pitot problem -- the static ports were taped over -- but the pilots (both the human kind and the auto- kind) were confused by the false airspeed readings. They are the reason my Seneca pilots knew that if they were 8 degrees nose up and had 31.5" of manifold pressure at 2450 RPM then the indicated airspeed was about 120.

It's an early instrument lesson: PITCH + POWER = AIRSPEED. Keep this in mind and a pitot tube failure is easier to handle.

I never flew a King Air with the pitot heat off. Not once. We turned on the "hot five" after cleared for takeoff: both fuel vent heats, both pitot tube heats, and the stall warning heat. Look at the picture: you can see that ice protection is very important in King Airs. And, the King Air has fantastic instrument redundancy: it has at least two of everything, powered differently, with redundant power sources and redundant buses ("dual-powered buses"). Not to sound redundant, but it was easy to be comfortable. Or even complacent.

I have seen a lot of pilots (myself included) chasing airspeed indications. We all know that's bad, and we know how to avoid it: use the right pitch attitude. One place that happens a lot is with engine failures. Best glide speed! people say, and raise the nose until the airspeed says, say, 60. The problem is that because of instrument lag, when the airspeed indicator says 60 the airspeed is really more like 50. Too slow! they say, and lower the nose until the airspeed says 60. Only now the airspeed is more like 65. There might be a number of oscillations. The pilot is focused inside instead of outside, and is generally behind the airplane. It's easier to set up the right pitch attitude, find a place to land, and only then fine tune the airspeed.

I often cover the airspeed indicator when failing the engine on a student. That's two lessons: instruments fail, and PITCH + POWER = AIRSPEED. Both taught long before instrument training. Maybe they should be taught well after, too.

Cold Temperatures and Low Altitudes

2009-12-30T20:50:00.000-08:00

[Note: I wrote the following for my EAA Chapter newsletter. Cold temperature altimeter errors scare me, since most of my flying is in a mountainous northern-tier state. And even if I have written about them before, everyone needs a reminder. So, here it is for everyone to read about.]

We've all noticed that it's Winter, both by the calendar and by the thermometer. Or maybe, like me, you've had your annual furnace failure.

Pilots love winter flying. The cold, dense air makes both your engine and your wings stronger, and you can see forever because the air is so dry.

But the days are shorter, and that means more night flying. The night air is still cold and clear, and the lights shimmer brightly. You need to watch out for fog forming in the valleys, but that usually happens sometime after sunrise unless there's an inversion.

Now imagine yourself flying from Denver to southeast Idaho on a moonless night. Before you left you looked at a chart, whether online or paper, and noticed that the route takes you near Wyoming Peak, elevation 11,378' MSL. So you put on the oxygen and climbed to 12,500. Smart, right?

Well, let's see. Keep in mind that extreme temperatures distort your altimeter readings. Hot temperatures make the altimeter read low, while cold temperatures make the altimeter read high. "High to low, look out below."

People often forget that the altimeter error from cold temperatures increases with altitude. There's a table in the Aeronautical Information Manual (AIM), paragraph 7-2, that illustrates the problem. By the table, when the surface temperature is -20C (which is not all that cold for our winters), the altimeter error is 140 feet when you're 1000 feet above the surface, 280 feet when you're 2000 feet above, and 710 feet when you're 5000 feet above. It's worse when the surface temperature is colder.

Now let's get back to you cruising along at 12,500. You're comfortable in the dark, because your terrain display isn't showing any red. But does it know the surface temperature? What altitude does it use, anyway? Since you don't know, you get the Afton weather, either by tuning the ASOS or with the nifty XM receiver. "Afton Municipal Airport," it says. "0303 Zulu weather. Wind calm. Visibility 10. Sky clear below 12 thousand. Temperature -40 Celsius, dewpoint -42 Celsius, altimeter 3001..." You dutifully set the altimeter, thinking "It sure sounds cold down there!"

That high up, with the Afton temperature -40C, your altimeter error is about 1,000 feet! In other words, while your altimeter reads 12,500, your true altitude is closer to 11,500, putting you within 200 feet of the mountain. Which you can't see. Letting your altitude slip a little could ruin your night.

Pilots are generally carefully about hot conditions. We know to use the usual speeds for takeoff and landing, and to ignore that feeling that we're going too fast, because we're not. We know to allow more runway, too, and more room to climb. Perfect technique in hot conditions keeps you safe.

But perfect technique in cold conditions can kill you. You can pick a good altitude and hold it within an inch and still hit a mountain!

In Canada, Air Traffic Controllers automatically apply the correction to radar vectored altitudes, but in the US we ignore the problem. So, think about this when flying in or near the mountains on a cold night, or while IFR. Choose a higher altitude than you think you need, because in fact you need it. And this isn't just a Rockies thing: look at Mt. Marcy in the Adirondacks (5,344' MSL, nearly 4,000' above the nearest altimeter-setting source), or Mt. Washington in New Hampshire (6,288' MSL, more than 5,000' above the nearest source), or even North Carolina's Grandfather Mountain (5,960' MSL, about 3,000' above Boone, the nearest altimeter source). If there are mountains and winter (yes, even North Carolina has a winter; the ASOS at Boone is showing 01C with visibility 1/2 in snow) then there are cold temperature errors.

(Does anyone know what the situation is in Europe? Do controllers adjust altitudes for cold-temperatures, or do pilots have this information?)

See the AIM for more.

Starting off on the wrong foot

2009-12-22T19:05:00.000-08:00

I'm confident that I will fly again, so I've started to review. Instrument flying really demands review, because the regulations are complex and changes happen quickly. (I've written about this before; see this post or this one.)

I found something interesting right away: a new departure procedure for Pocatello, pictured above. It's called the
KNURL ONE (OBSTACLE) departure.

A great way to improve your understanding of IFR flight, as well as your chart-reading skills, is to spend a lot of time asking "Why?" Why is there a new departure? Why does it use that radial? Why does it use that altitude? And the like.

The FAA uses two classes of departure procedure, SIDs (Standard Instrument Departures) and ODPs (Obstacle Departure Procedures). Wait, isn't the term SID deprecated? No; now it is undeprecated, or is that repricated, or maybe vindicated? Whatever you want to call it, see the preamble to the TAKEOFF MINIMUMS AND (OBSTACLE) DEPARTURE PROCEDURES section of any approach chart book. SIDs are back.

The first thing to notice is that it is an Obstacle Departure Procedure. The obvious clue is the word (OBSTACLE) in the procedure title, but there's a subtler clue as well, which is easy to miss because it is often, well, missing. SIDs generally do not include altitudes, and many that include altitudes use the notation (ATC) to indicate that the reason for the altitude restriction is for the convenience of Air Traffic Control; see for example the WHAMY ONE departure out of Portland, Oregon. You also see this with climb gradients, when ATC wants you to climb like crazy to get above the inbound traffic.

With IFR procedures the first consideration is altitude, so if you don't see one there's a reason. And ODPs, because of their nature, always include lots of altitudes. So, in the KNURL departure from runway 3, you read "Climb heading 028 to 5500, then..." That's to get you over the grain elevator.

After maneuvering away from the obstacles, the departure has you fly outbound on the PIH R-269 to KNURL, which is at 17DME. Ouch! That's a long way in a 172 or even an Archer, but it makes sense if you are headed west on V-500, which uses R-269. But that makes no sense in a 172 or Archer, since the MEA on V-500 between REAPS and DERSO is 17,000 MSL!

ODPs are optional and may be flown without a clearance, although I would consider it good form to inform ATC if you decide to fly it. So why would you follow an optional departure procedure that takes you down the radial you want to fly?

Worse, the ODP altitude is 7,500MSL. This leaves higher altitudes available for ATC, which is good. But it has you flying westbound at an eastbound VFR altitude, which would make me very uncomfortable on a marginal VFR day. If I had the equipment to get to 17,000 I would rather file for that altitude (or even higher) rather than fly head-to-head with the VFRs, nice folks though they are, down low.

Now let's look at how this DP fits with the enroute structure. There are six airways at Pocatello VOR, and because of terrain most departures are on one. Starting at north, V-21 goes northeast to Idaho Falls. Pocatello departures are unlikely to fly 17 miles west before turning northeast, especially since there is nothing to hit in that direction. Departing runway 21? Turning right at 400AGL will put you on the 016 radial? Departing runway 3? Just turn a little to the left. (Virtually no aircraft depart runways 17 or 35 except under extreme conditions, which would require some careful thought.)

The next airway is V-21 southeast bound. There is a crossing restriction at the VOR, so maybe a little jaunt down the 269 radial would be comforting. But all the way to KNURL? Plus, if you are on the ODP you are restricted to 7500, and the crossing altitude is 8000.

V-269 southeastbound follows the 235 radial, and the MEA is lower. If you're going that way, just fly V-269.

We've already discussed V-500.

V-269 northbound goes toward Salmon (LKT) over relatively low terrain for the first 50 miles. You are perfectly safe just turning to intercept, except perhaps departing runway 17. The same applies to V-257, toward DBS.

The other departure direction is toward Jackson Hole, WY. The heading is about 045, so one might be tempted to make a left turn departing runway 21, but that throws you toward high terrain. I always flew the right downwind departure, passing over the airport.

The conclusion?

Nobody will ever request the KNURL ODP!

It is still possible that ATC will assign the departure in order to get an airplane moving. Shoot the departure to 7500, keep the inbound at 9000, and everybody is happy. Once the departure is in radar contact they can vector it to where it wants to go. And if there's lost comm? Well, the departure is stuck down at 7500 for 10 minutes.

Still, you would interpret that as starting off on the wrong foot.