Saturday, December 31, 2011

Local versus Global

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.

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Tuesday, December 27, 2011

Cloud Phase

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 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.


Tuesday, December 20, 2011


According to this article on, 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, 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.

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Friday, December 16, 2011

Unusual Attitudes

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.

Monday, December 12, 2011


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.

Sunday, December 11, 2011

Flight Review

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?

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