Thursday, August 28, 2008

Brain vs. Muscle

In flight instruction you just don't know what's going to work. The same thing is true in classroom instruction, but in flight instruction there is so much more intimacy. It's possible and even, I hope, likely, that in my classroom career I have said or done things that really helped students understand, but in a room with 32 faces it's easy to look at the wrong one, and miss the "Aha!" across the room.

One-on-one teaching is more satisfying. Take this evening: I was helping my 10-year-old son with his math homework, and for some reason there was something that just didn't make sense to him. I tried several explanations, really groping around trying to see what worked, and when I found something that worked his face lost that frustrated look and he actually said, "Oh! I get it!"

The difference between Math and Flying is that flying involves more muscle memory. Here are there examples from flight instruction in which I got a little lucky and said or did the right thing at the right time, and had the joy of watching someone jump the gap.

A new glider student was having a lot of trouble flying formation with the tow plane. He was overcontrolling. We made wider and wider swings behind the poor bewildered tow pilot until I would have to take over. This is not unusual. My words and demonstrations just weren't getting through, even though I thought that they were brilliant. (It doesn't matter what the teacher says, it matters what the student hears.)

Almost in desperation, I suggested that he hold the stick closer to its base. I was trying to reduce his lever arm, which might or might not stop him from overcontrolling. It did! He got into position behind the tow plane and stayed there.

A power student was struggling in the traffic pattern. He did OK when I made the radio calls, but he was getting ready to solo and I soon would not be there to help. Each time he thumbed the push-to-talk switch he would climb or descend or slow down or speed up or do something that he shouldn't have done.

This is not unusual, either. I had to find a solution. Sometimes I have done this on the ground, having the student mimic the actions in the pattern while telling a story. But that wasn't working.

He asked me to fly a pattern so he could watch. OK, I thought, but I try not to do a lot of flying while teaching. (More on this later.) So I flew a pattern.

"You key the mike with your forefinger," he said.

"I do?" I was unaware of this.

"I'm going to try that, too."

So on the next pattern he used his forefinger rather than his thumb to key the mike. Do not ask me to explain the neural pathways, or wrist physiology, or vagal response, but ... it worked! From then on his patterns were fine.

A glider transition pilot was having a devil of a time with slips. As you probably know, a slip is when you use opposite bank and rudder to make the plane fly a little sideways. This increases the drag substantially, so you can lose a lot of altitude. This is so common in gliders, where we tend to approach the landing with extra energy, that it is required on the flight test.

This student already had a power license with a tailwheel endorsement, so I knew that he had done slips before. Maybe I didn't bear down enough, thinking that this was just a matter of checking off the box before sending him for a flight test, but he just couldn't do it. I explained, I waved my hands sideways through the air, I coaxed, cajoled, and encouraged, but it just wasn't taking.

Remember: I am a blogger. I like words.

On our second session of slips, I gave up on words and said, "Do you want to see me do one?" I don't like to fly while instructing; we are there for the student to fly. In this case the student was already a pilot, so I was even more reluctant to take his flying away from him.

So we told the tow pilot to take us to pattern altitude and I took the controls and did a slip. Not even a great one, really a barely adequate slip.

"I think I've got it!" he exclaimed. We did another pattern tow and now he did a slip and did a pretty good job if it, too.

The unifying thread in these three stories is that words are not enough to teach an activity. We don't learn baseball, piano, driving with a clutch, how to draw blood, or a gazillion other physical skills by words alone. In medicine, the rule is "see one do one teach one:" the words come last, not first.

In other words, Do what I do, not what I say.

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Sunday, August 24, 2008

Red, Blue, and Grumpy

I am not a fan of the current style of political debate. The labels "Red" and "Blue" reduce complex issues to mere cartoons. This stifles thoughtful debate, which is rare these days. My rule about the columnists in my local paper is that I read until the first insult. I generally put the column aside before I finish the first paragraph.

I thought about my previous post while flying a 172 down to the glider club. It consisted of a lot of petty stories about other people trying to stretch or break aviation regulations. But pointing out the mistakes of others is a destructive act, and I want my contribution to be constructive. So I deleted it. I hope nobody read it.

So let's be constructive. Why was I flying a rented 172 instead of my beloved club Archer?

Today is the last day before school starts, and I was determined to spend as much of it in the air as possible. I reserved the Archer, and contacted my students and the tow pilot. In fact, a lot of my friends planned to fly today; it was bound to be fun.

I got out to the airport and preflighted the Archer, but I did not see the "ELT not installed" notice until I went to start it. The ELT is the Emergency Locator Transmitter, which is designed to activate in a crash and send out a rather distinctive signal on the emergency frequency, 121.5 mHz. A functioning ELT saved the life of the passenger in this accident guiding a helicopter to a dramatic nighttime on-the-ice rescue using night vision goggles. Or, think about the Learjet (jets were not required to have ELTs until recently) that disappeared in New Hampshire. Here is the accident report. Notice that it took three years to find the wreckage.

So as a rule I like ELTs.

And in fact the rules require an ELT: see 14CFR91.207. Actually, there is an exception to the requirement when the ELT has been removed for repair (I forgot about this, but did not have enough information to decide to launch without it, even if I had remembered), but remember that night vision goggle rescue. I prefer to have one.

So I did not take the Archer; I rented a 172 from the local flight school, which fortunately had one available for the day.

In aviation we spend a lot of effort avoiding things that may never happen. Sure, I could fly without an ELT, and it would probably be OK. But it would not definitely be OK. And if you're wrong? As Phillip Larkin wrote of death, "Most things may never happen: this one will."

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Saturday, August 23, 2008

Regulations and Speculations (by lawyers, for lawyers)

[deleted by author; see next entry]

Thursday, August 14, 2008

View from the back

So it was time to leave behind the usual western USA world of school prep, glider checkouts, and fun BFRs and head Back East (this is a proper name in my part of the world) to visit my parents. We were flying out on Delta, and I was looking forward to a long period of sightseeing, playing games with my daughter, and watching for other airplanes. Kind of like a four hour leg in an EFIS King Air, without the need to check in with Center.

But I was wrong. You can learn about flying, even in seat 26A.

We were to change planes at KJFK. The kids were excited to see a little of New York, and since KJFK was using the VOR-DME 13L approach (the one where you track a radial off Canarsie VOR and follow the lead-in lights to the threshold, the closest thing to the old Kai Tak approach you're likely to see in the USA), we had a nice view of the Verrazano Bridge, Statue of Liberty, and Empire State Building while I kept track of flaps and gear, which came out only on close-in base.

But then came the taxi. JFK has a lot of taxiways, and more airplanes than gates. We taxied in a big clockwise circle around the airfield, the only relief being the sight of an Airbus A380 at the gate. We were headed toward a parking area somewhere near taxiway K. We taxied west and north, passed some parked airplane, people-movers nudged up against them. Then we turned left on LA, and left again on B.

Our crew had missed the turn.

Our parking spot filled with ground vehicles during the delay, kind of like parking spaces in Manhattan. We sat while they cleared it out. Passengers missed their connections. Ugly.

I was completely sympathetic, remembering a time at San Francisco. My alarm had gone off in Oakland at some oh-dark-30 hour for a medical flight from San Francisco to Reno, something to do with a transplant. The Bay Area was IFR, and I had to fly to San Francisco to get the team. It was already busy, and the vectors came thick and fast. At least I could get the KSFO ATIS on the ground in Oakland.

The ATIS said "expect ILS 28R," the first controller said "Expect ILS 28R," but the next guy had "Turn right heading 260 maintain 2400 until established cleared ILS runway 28 LEFT." Grrr.

The team was waiting and I was on the ground only long enough to pay the landing fee. My head was buzzing from the early wake-up, bad coffee, and the cockpit scramble with the runway change. I got the ATIS and called ground. I needed to taxi from the Signature ramp (northeast corner of the airfield) to runway 1L, at the southwest corner. At least it was daylight.

But I was on my game. I had the taxi chart out, and took my time, holding short where instructed, monitoring tower, and arrived at runway 1R as required. I was number three for departure, and now that I was stopped I took a moment to look around. After all, SFO is a cool airport, and I wanted to do a little sightseeing.

Airplanes were everywhere. RJs, 747s, A340s, even a few Mad Dogs (got a ride on one of those yesterday, too). The airfield choreographers were on their game, too, and all of these airplanes were at or going to the right place.

And all of them had at least two pilots up front. I got that weak-in-the-knees I-just-dodged-a-bullet feeling. I was all alone.

The thing is that San Francisco tower, like San Francisco, is always gracious and mellow. I did not hear JFK tower yesterday, but it's hard to imagine that much Marin County "go with the flow" attitude has made its way up there. Oh well.

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Wednesday, August 6, 2008

Hot Rod Lincoln

Asleep at the Wheel do a version of Hot Rod Lincoln with a spirited introduction by Roy Benson. "The following story is true," he says, in his best Jack Webb voice, "only the oil has been changed to protect the pistons." The following story is true, but some details have been changed to protect the guilty. I heard it during my travels this summer. In honor of The Wheel, let's say that it happened in Texas.

Listen along while you read:

A charter company runs a small fleet of older airplanes. One of their pilots was doing a preflight (this is good), and noticed that the hydraulic fluid was low (this is also good). My first instructor, at about hour two of my career, pointed to the hydraulic reservoir in the Warrior and said "Check it, but if it's low let the mechanics fill it. They have some special way of doing it that keeps the air bubbles out." I left it at that.

I have a lot of time in King Airs, Senecas, and Centurions. The landing gear in these airplanes is hydraulic, and they are all different. The Seneca has a reversible electric pump. There were three versions of the Centurion hydraulic system, as far as I know. The original used an open-center (always circulating) engine-driven system with massive manually controlled valves. Next came an electric motor version, but the valves were still manual. These two systems had a large gear lever in the cockpit, I suppose so you could get enough mechanical advantage to move the valves. (The Fairchild F-27 reportedly came with a rubber mallet to help the crew move recalcitrant valves into position.) The final Centurion system was all-electric, with electric valves that failed in the safe position (no power means that hydraulic pressure opens the doors and pushes the wheels down). It had a little teeny gear switch, since all it had to move was electrons. These systems are complex, and I had a lot of students really struggle to understand them.

In more than two thousand hours of flying these three airplanes, I have never once added hydraulic fluid. I have lost fluid due to leaks (I once lost all of it in a Seneca, but following the checklist made this a non-event), but I have never added fluid. Never.

But this pilot thought otherwise, and went into the hangar and grabbed some hydraulic fluid, and poured it in the reservoir. This put a lot of air into the system, which is what saved him...

You see, this airplane has some hydraulic flight controls. No hydraulics means an airplane that is difficult or even impossible to control, sometimes called the "lawn dart" version of the airplane. The best outcome would be a belly landing, the worst would be...

This pilot ended up not flying that day, and the next day another pilot doing a preflight noticed that the hydraulic fluid level was high. Uh-oh. He called maintenance, and they, unaware of the added fluid, thought that there must be air in the system. They started to "bleed" the system to get the air out. Uh-oh again: they discovered that the pilot had added the wrong type of fluid.

I doubt that pilots know much about hydraulic fluid. I mean, my instructor told me to leave it alone. But at some point I thought that my aeronautical career would be advanced by taking the Flight Engineer written exam, so I spent a fair amount of time studying aircraft systems, including hydraulics. Hydraulics are pretty simple, in principle: in English units, psi in equals psi out, and more "si" (square inches) at the output end means more "p" (pounds) of force. So far so good. But there was a lot of material in these books about hydraulic fluids. Some of them are very nasty substances, indeed. One of these got into the airplane.

The damage? Seals, lines, and pump destroyed. Lots of down time. Angry customers. A pile-up in the maintenance shop, with retail customers angered because there was nobody available to work on their airplanes.

The bill? Right around 15% of the aircraft's value.

Fifteen percent of the aircraft's value, lost in one moment of failing to stop and think.

Let's remember to stop and think.

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Monday, August 4, 2008

How Far Can You Go?

I did a couple of trips last week as a "hired gun" first officer for a local company. These are fun, and the pay is pretty good. They only let me fly the empty legs, which seems fair, but the head of their flight department respects my experience and encourages me to do some instruction. I usually find something worth discussing, so am comfortable logging the time as "dual given." Some regulation junkie will probably find a way to say that this amounts to padding my logbook; he or she is entitled to that opinion. But when the pilot involved knows more at the end of the flight than at the beginning, I say that instruction has been received.

The big surprise this week was a flight plan to the midwest. I hesitate to call it a plan: there were only two fixes, the departure airport and the destination airport. This has been a topic for friendly debate between me and this company's pilots. They contend that this kind of planning tells Air Traffic Control (ATC) that it is OK to send the airplane wherever works best. But you know what? ATC will send the airplane wherever works best anyway. So there is no advantage.

What advantage do I see? Imagine a trip of 1000 nautical miles. This is almost 5% of the Earth's radius, so the big picture really comes into play.

  • If there is a center of high- or low-pressure, you can save a lot of time by passing on the proper side (when westbound, choose the polar side of a high, the equatorial side of a low). In this case, there were no major high- or low-pressure centers along the route. This route is long enough that terms like "polar" and "equatorial" really mean something.

  • You have no idea what the computerized flight planning software uses to estimate the winds aloft, because it all gets rolled up into one composite estimate. It is very unlikely that the winds will be unchanged over a route that long. Your strategy will be a lot different if you are flying into a decreasing headwind than if you were flying into an increasing headwind. This strategy depends on...

  • You don't have a howgozit. That's a corrupted spellingof "How goes it?," i.e., judging whether you are making adequate progress or not. [Gulp: a google search for "howgozit navigation" comes up with my book first!] Will you have enough fuel to make it? The last part of our flight would cross a significant amount of Great Lakes water, and the possibilities for refueling over the Great Lakes are few, so we would need to know early that there might be a fuel problem.

    The thing is that if it appears that you will be short of fuel, and you have a solid forecast of a decreasing headwing/increasing tailwind, then you are not short of fuel. If it appears that you are short of fuel, and the forecast is less than solid or the headwind is forecast to increase, then you are really short of fuel.

  • The comparison between the actual winds aloft and the forecast winds aloft is one of your best tools for judging the accuracy of the forecast. But this is impossible if all you have is one composite number that is supposed to work for 1,000 miles.

  • On the other hand, I really expect to fly direct. I compare the time abeam the fix to the predicted time to decide whether I am ahead or behind.

    We had a pleasant trip, except for dodging a few thunderstorms. We talked about some of these issues. On the way back the captain put a few waypoints onto his flight log.

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