Saturday, February 8, 2014

Navigating Away

The automated observation at the airport where I fly gliders was insisting, repeatedly, that the ceiling was 6,000'AGL, but those of us who fly the ridge there knew it was below 3,000'.

I was doing a high-performance checkout and today's lesson plan included stall recognition and recovery.  The standard minimum altitude to be recovered from a stall is 1,500', which might be OK in a Cessna 150, but 3,000' is on the edge of "high enough" for a plane with higher wing loading.

It was the pilot's first flight in the airplane, too, which pretty much guaranteed that we would be climbing higher than I specified.  The chance of accidentally entering the clouds was low, but higher than normal.

But another part of the lesson was using the GPS in the airplane.  For too many pilots GPS use doesn't get much beyond the DIRECT button, and while this pilot would have the opportunity to revert to that behavior after the checkout, I wanted to be sure that he had seen what the unit could do.  (The FAA defines learning as a change in behavior based on experience, so I guess if the experience wasn't going to change his behavior then he wasn't going to learn anything.)

So after the runup I gave the pilot a GPS exercise: program a route from a waypoint on one of the instrument approaches to the south, through the airport, to one of the waypoints to the north.  This gave the pilot a line on the moving map that he had absolutely no intention of following, except if we lost visibility, in which case that line would show us which way to fly to safety.  After the flight, we plotted the "route" using skyvector.com, and it looked like this:
As you can see, the "route" would have kept us away from the mountains to the East and to the West.

I have written before about ideas like this: see here, for instance.  This post's end copies that one:

The conclusion is that, going back to Bowditch, a wise navigator uses every available resource. Even without the equipment to fly those approaches, you can use the data to make your flying safer and more efficient.

Thursday, January 9, 2014

One Million Dollars

In the Austin Powers movies Dr. Evil, hopelessly behind the times, wants to hold the world at ransom for [pause] One Million Dollars.  The joke is that that's not much, but for me and probably you that is a very large amount of money.  Even for an airline, that is a very large amount of money.

A recent story in Aviation Week and Space Technology caught my eye and reinforces my tendency toward acquiring lots of data and acting rationally.

An unnamed airline was operating  a flight from the West Coast of the USA to Europe.  (I was once a passenger on a Boeing 747SP from London Heathrow to KLAX; this is a long flight!  For me, with clear skies and daylight all the way, it was a spectacular flight, allowing me to see Iceland, Greenland, and Hudson's Bay.) This crew got a "Low Tire Pressure" warning somewhere over the USA.

These days every automobile service center is familiar with these warnings.  When the weather gets cold lots of cars get these warnings, by simple physics: a 25 degree Celsius temperature drop from close to standard is, directly, a 10% drop in pressure.  So when the temperature drops from summer's 30C to winter's 5C the colder tires really have lower pressure.

Presumably the engineers who design these sensors for aircraft compensate for the expected pressure change of 30% when an airplane leaves 30C KLAX and climbs to the -50C stratosphere.  This tire was genuinely leaking.

The airline's maintenance department took several pressure readings at 20 minute intervals to determine the leak rate, and calculated (that's the word I like!) that the tire would be flat on arrival in Europe.  This didn't worry them operationally, but someone remembered that every time an airplane landed in Europe with a flat tire it cost the airline $1,000,000.

With this information the dispatchers suggested that the airplane land while still in the USA, while the tire still had air.  The crew did so, the tire got fixed, and the passengers were on their way after a small delay. This was probably another complex calculation: find a maintenance base with a tire available that was far enough along so that the airplane was below its maximum landing weight.

The airline saved $1,000,000.

Now one of my mottoes (see the sidebar to the right) is that a pilot should never think about money while in the air, but with an outcome like this I conclude that it was a good decision.  So I suppose I need to update my motto?


Friday, January 3, 2014

Habit

Readers know that I am a big believer in habits.  When you're on fire your habits will take over; you're unlikely to invent a new technique.

No, this is not about New Year's Resolutions.

My first flight of 2014 was a paid maintenance flight.  Salt Lake City (KSLC) was really low IFR, pushing Category II minimums.  Good thing I wasn't going there.  Or was I?

As I departed home I saw a landing light coming down the airway from KSLC and sure enough pretty soon the Tower was talking to a SkyWest flight that had diverted after a long hold at KSLC.

Radar coverage is sparse in this area so Flight Following is generally unavailable; still I decided to at least listen to Center (the habit).  I heard a lot of non-standard phraseology:

"Climb and maintain Flight Level 290, I have to keep you below the holding stack."

"Are they missing [the approach] in Salt Lake?"

"What's the Salt Lake RVR?" [The answer was "I'll check" then "1,000 feet, but it looks like it's going down."

"Can we just circle visually?"

My destination, Twin Falls (KTWF) is one of the few non-radar approach control facilities in the USA.  I usually call Approach (that's the habit) and they usually don't care, but today the approach controller was juggling two unexpected jets in his head and it seemed wise to let him know that I was coming.  (My groundspeed was 65 knots, I would be coming for a loooong time.)  For the moment both jets were above me but I knew that that would inevitably change, so I stayed north of the runway 26 final approach.

"55J, say distance from Twin Falls please?"  He asked three times.

One jet was on final and the other was on right downwind, metal-to-metal with me.  I made sure my transponder was on so I'd show on the RJ's TCAS.

About 15 miles out I saw the RJ turn base and called "I've got the RJ turning right base in sight."

"Follow that RJ to the airport, contact Tower now on 118.2."

Now the use of the word "follow" might have been correct by the ATC handbook but I was indicating 95 knots with a 40 knot headwind, while the jet was indicating 200 knots with the same headwind.  The jet would be landed and the passengers deplaned before I landed, but I agreed and headed in.

The lesson here is that this was all no big deal, because of my habit.  It's my habit to contact Approach Control, even though 9 times out of 10 they don't care.  It's my habit to set up the radios for an instrument approach, so when the Tower asked for my distance all I had to do was look down at the DME display.

Habits.

Sunday, November 24, 2013

A Disaster Waiting to Happen

As the proud owner of a new medical certificate it was time to spend a sunny Saturday at the airport hoping for a new student.

The first thing I noticed, though, was a pressurized piston twin (let's call it an Queenstar to protect the guilty) sitting on the taxiway surrounded by the Lectro tug and a bunch of guys scratching their heads.

There's one Queenstar based on the field, so I went inside and asked the receptionist "Is that Bob's Queenstar out there?"

She kind of grinned.  "The left engine stalled as they were taxiing in, and the right was making lots of smoke."

Before you think "Oh that silly girl doesn't know what a stall is," keep in mind that she is a licensed A & P mechanic.  She meant that the engine stalled, just like a Chrysler Slant Six with a bad clutch on a steep hill.

At least it wasn't Bob's.  I looked up the N-number and saw that it had come from two states away.
Someone came in looking for them, and we buzzed him out onto the ramp just as the tug deposited the airplane in front.  A bunch of people came in followed by the line guy, picked up a small package, and went back out to put it into the airplane, setting off the alarm as they forced the door open.

While they were out we quizzed the line guy (not an A & P, but almost done with his Private).  What did they say?  They refused his offer to call maintenance, and refused fuel as well.  This was starting to sound bad.

I checked on flightaware and was surprised to see that this particular airplane hadn't filed IFR for more than two years.  Now a Queenstar is a fast pressurized twin, and the way you get the most out of it is to file for FL200 or FL210 and let 'er rip!  But these guys (who lived in a foggy part of the world) just waited for VFR and for all we knew they flew at 3500 MSL unpressurized.

They got back into the airplane and we all stood at the window and counted the starts.

Five tries on the left, with no sign of combustion.

The right engine started on the fifth try.

They tried the left nine more times.  This is not looking good, but there is so little that one can do after they've refused maintenance.  It was not funny.

But the left one got going and they started to taxi out.  No call to ground, but they stopped at the edge of the movement area, turned downwind, and started to do a runup.  Oops!  They throttled back and whipped around a started to do a runup facing into the wind.  I couldn't hear that the props were exercised, but there were more than the expected four magneto checks.  Then they went to full power, the airplane thrashing and bucking and backfiring.  More magneto checks.

They taxied back in and shut down in the fire lane.

"We've got a bad mag on the right engine," they said, and maintenance was called.

And disaster was averted.

[revised 9 Feb 2014]

Saturday, October 26, 2013

Dolphin Flight


In gliders it's called dolphin flight.

In rising air the craft is slowed;
it lingers in the lift.

In sinking air the speed's increased
to exit from the sink.

The craft arcs up then plunges down,
a dolphin playing in the waves.

The wing's finesse is sacrificed; finesse
is local, but essence is global.  The larger
picture wins.

Power corrupts the picture with the opposite
effect.

The power pilot, sinking, slows the craft.

The power pilot, climbing, adds more speed.

The power pilot lingers in the sink,
and exits from the lift.

At times this is the only course.

In clouds the craft must hold the altitude
strictly; a change of height raises the
spectre of colliding with a craft below.
Holding altitude wastes the essense the glider
pilot gleans from the movement of the air.

A collision robs the craft of all of its finesse.

But when flight is pure the need for stricture
disappears.  Essence is more important
than altitude.

Seeking essence, the power pilot
in rising air slows less than a glider might
but nonetheless allows the craft to climb.
In sinking air, allow the craft to sink.

Altitude is essence.

Every push or pull of the controls uses
essence.  More essence than an engineer can calculate:
the constant jerking angers, or worries, passengers.

The air's whims cannot pass unchecked.  If the
craft climbs too high the peril of hypoxia might
raise its euphoric head.

If the craft sinks too low there is the peril of the ground.

A small change brings on none of these
effects, so let the craft rise or sink a little
with the air.


Wednesday, October 9, 2013

What? No Government?

For the record: I sent my medical recertification data to the FAA the first week of August.  It was my usual obsessive-compulsive-A-student package with 27 glossy 8 by 10 photos with circles and arrows and a paragraph on the back describing each.

My medical expired at the end of August.  Right now I am in the middle of an extended checkout of a new Mooney owner who is legal to be PIC so I don't need a medical.  (And, it's fun.)  But I will soon!

I have not even taken the disheartening step of calling the FAA to see if they are working on my medical.  I just assume the answer is no.  And I'm afraid that when the Washington Baboons get their act together and work resumes the FAA will decide to determine the length of the validity of my authorization based on when they got around to looking at the results, not on when I sent them.

The FBO at the glider port has a Cessna 162 for rent and it's starting to look pretty attractive...

Thursday, August 8, 2013

Sleep

Airport lounges everywhere are full of pilots sleeping.

Cold logic tells us why.

The pilot must prepare the craft.

Alone, it takes an hour, sometimes more.

With help perhaps a little less.

Flight plan, manifest, takeoff and landing distance.

Performance.

Fuel and bags, a crouch to see the fire bottle gauge.

But also coffee, ice, amenities, snacks.

Perhaps the potty service, too.

And then the flight itself.

For many, there are two, one to bring the craft to
the customers, the other to bring the customers to
their task.

(The better landing always happens first.)

Before most folks arise the pilot works for hours.

While some see fate the hunter, others see fatigue.

In its grasp, essence conversion is too slow.

Ideas do not arise in time, calculations become missed.

In its grasp, the muscles move without finesse.

Sleep itself becomes a form of essence.