Tuesday, May 10, 2011
Takeoff Mistakes: The Critical Minute
It all has to come together in the first 60 seconds, or the rest of the flight may not matter
There’s less margin for error during takeoff than in any other phase of flight. Excluding a midair collision, the only time an accident can occur is when the airplane collides with the ground, and since takeoffs typically demand higher speeds than landings, the accident potential is greater.
The vast majority of general aviation aircraft can land in about two-thirds the runway required for takeoff. For that reason, you’re only kidding yourself if you sneak into a short runway and assume that because you got in, you can get back out. Not always so. Most of us will never operate into strips that short, but sometimes, there’s no choice.
(Fifteen years ago, I had a graphic demonstration of that principle on a trip from St. Louis to Subic Bay, Philippines, in a Cessna 421. When I was approaching Subic for the final landing of the trip, the controller advised that available runway length was 500 meters. I knew that had to be wrong as the approach plate suggested I should have 2,900 meters. I asked him to repeat. Again, he said available landing distance had been reduced to only 500 meters because of resurfacing. I had left Guam nine hours and 1,600 miles ago, and there had been no NOTAM about Subic, not necessarily a surprise in that part of the world. I was down to minimum fuel, and it would have been dicey getting back to Manila. Fortunately, it’s possible to ground a 421 in 300 meters if you have to. I had to. No way I would have considered going back out from the same runway, as the 421 requires at least 600 meters for takeoff.)
Back in late 1988, when Piper switched from a Continental to a Lycoming engine on the Malibu and renamed the airplane the Malibu Mirage, I delivered the first production machine to Kassel, Germany. On takeoff from Glasgow, Scotland, on the final leg, I lifted off and immediately saw fuel contrails pouring from each wing.
Both fuel caps had come off the airplane. The fueler had merely placed the caps in the wing detents without cam-locking them down. My fault, no one else’s. After I landed, the fueler advised me in no uncertain terms that they NEVER tighten down the caps—that was the pilot’s job. He was correct. Fortunately, both caps were recovered in good shape with nothing worse than scratched paint.
The volatility and quantity of fuel are other concerns that might seem obvious but often aren’t. Misfueling can happen to even the best pilot, and you may not know you have the wrong grade of fuel in the tanks until you push up the power. Similarly, initiating the takeoff roll on a semi-empty tank would seem a really dumb mistake, but some older airplanes made it possible.
I used to own an old Bellanca that had three fuel tanks, two wing tanks and an aux fuselage tank. When you selected a given tank, you had to also position a second fuel-quantity selector to read that tank’s fuel state. If you switched the tank indication selector to a full tank but left the actual fuel selector on a near-empty tank, you might get an unpleasant surprise a few feet in the air. Some older Bonanzas utilized a similar system.
Another procedure suggested by an Alaskan bush pilot was to start the engine on the least-full tank (assuming it had some fuel in it), and switch to the fullest tank before taxiing to the run-up area. Switching tanks can introduce air bubbles into the system and cause a slight hesitation in power as much as a minute or two later—not a good idea, especially during a short-field takeoff.
Checking control continuity prior to departure would seem such a natural precaution that no one could possibly forget it. Wrong! As incredible as it may seem, people still leave control locks in place and push the power up for takeoff. Ten years ago, a client did exactly that in his 340 at Santa Monica Airport in Southern California, and he and a passenger paid the ultimate price. I was scheduled to leave with him on a vacation trip across the Atlantic the following day.
Intersection takeoffs are almost universally a bad idea. Yes, I’ve made them on occasion, but they’re almost never defensible. Giving away any available runway is rarely smart. A great instructor, Gary Halopoff, used to ask how stupid I would feel if I made an intersection departure 1,000 feet from the threshold, then lost an engine at rotation, and ran off the end into the overrun or the approach lights, when I could have stopped short if I had used the entire length.
Finally, a nearly incomprehensible takeoff glitch in a special type of airplane deserves mention, though it hardly ever happens any more. The Cessna Skymaster features engines on each end of the fuselage rather than mounted on the wings, and some pilots have been known to initiate takeoff after the rear engine had idled out, all the while wondering why the airplane accelerated like a heavily sedated Galápagos turtle. For that very reason, Cessna mounted a large red alternator inop light for the rear engine, and revised the flight manual to direct full power on the rear engine before advancing the front throttle for takeoff. If nothing happened when the right (rear) throttle went forward, that was a sure sign that things weren’t right.
Most pilots who are simply awake just don’t make that kind of mistake, it says here....
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Labels: Accident Statistics, Decision Making, Emergency Situations, Features, Flight Planning, Flight Training, Flying Skills, Pilot Safety