Tuesday, September 20, 2011
Is the impossible turn, in fact, possible?
If that isn't enough to start you thinking, shallow banks have a second fatal flaw: They produce large-radius turns that carry the plane impossibly far from the runway to which you're attempting to return.
Over the years, I've heard a few instructors acknowledge there might be something to using a steep bank attitude in a turnaround attempt, but with the caution that it would be foolhardy to recommend it: Lack of skill and panic would inevitably make such attempts dangerous. Nonsense. I would venture that pilots who can't learn and master 45-degree or 60-degree banked turns shouldn't be flying.
What about panic? This is obvious: Train through it. Give a pilot a task and the certainty that it will work, and panic recedes. It's shameful to use emotion as a justification for failure to train.
You need to experiment in your own aircraft before you form your opinion about turnarounds. Consider a Cessna 172 with a failed engine. Starting from Vx pitch attitude and airspeed, and using a 60-degree bank angle, it's possible to reverse course with less than 300 feet of altitude loss. Even allowing for several lost seconds of "disbelief time," this translates into a very real safe turnaround target of 500 feet AGL.
The critical key to success in turnarounds is practice and preparation. If you don't know that you can do the maneuver safely, you won't be prepared to react as quickly as an emergency demands.
Practice is simple: Using a conservative altitude, establish a stable climb at Vx (not Vy), then cut the power, noting the altitude. Allow for a couple of seconds lost in disbelief, then lower the nose as you bank steeply and pull to a high angle of attack. With any crosswind, the turn should be initiated into the wind to limit radius. Some degree of prestall buffet is desirable, and inadvertent stalls are probably inevitable as you learn to identify the limits. You'll be amazed at how quickly and in how little space you can get turned around.
There are two fairly obvious prerequisites: first, you need to be able to make a gliding turn with a 45-degree or 50-degree bank angle at high AOA without losing control of pitch, bank and yaw. Second, you have to be comfortable with the possibility of causing an inadvertent stall in a steeply banked attitude, a stall that will require recovery without abandoning the turn.
Now you see why turnarounds are called "impossible": To the shame of the FAA and virtually the entire teaching community, few pilots are ever encouraged to develop these critical skills. With no preparation, there's little wonder that turnaround attempts often wind up in disaster: You might as well expect students to go out and do spins on their first solo.
If this style of maneuvering is even faintly foreign to you, get a competent CFI to come along. If you get a blank look, go find another. Once you've developed the necessary turnaround skills, the second key to success is correct identification of your personal safe-turnaround altitude. The number changes with four important variables: pilot skill, airplane model, runway length and density altitude; it can be determined only through trial and error in a specific airplane model.
Very few pilots are prepared to fly as I've described. Yet most survive, so why bother with all this? The answer lies in the very statistics that produced the "never turn back" credo in the first place: Enough pilots have gotten killed trying the maneuver to indicate that takeoff emergencies do happen. If you fly a single-engine airplane long enough, you'll experience an engine emergency. Luck (bad) plays a part, and your engine problem may occur at low altitude shortly after liftoff. If you aren't prepared, maybe you shouldn't be carrying around your family and friends.
Michael Church has been a CFI since 1967 and Chief Instructor at Sunrise Aviation in California since 1985. He has been a NAFI Master Flight Instructor and Master Aerobatic Flight Instructor since 2002. This article is revised from columns originally published in Pacific Flyer.
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