I operate an aerobatic flight and spin-training school in Tennessee, and one of the things I'm finding out is that many new flight instructors need more knowledge of spins, including how to recognize the onset and development of a spin, and how to recover from one (see "Instructor Report: Teaching Spins," p. 62).
At present, I'm teaching aerobatics and spins in a Cessna 152 Aerobat, but I have used other spinnable airplanes during my previous 56 years as a flight instructor. I've had instructors in the course whose spin experience has varied from a good background in spins to those who've never been in a spin. "My instructor was afraid of spins and so just signed me off," they tell me. This is a practice that should get somebody's flight instructor certificate revoked.
My spin curriculum for flight instructor candidates includes three hours of ground school and two flights with many spin recoveries, including a 20-turn spin (over a nontowered airport with a 5,000-foot runway) and a recovery from a developed spin using only airspeed, turn and slip, and altimeter.
The 20-turn spin -- done only once and for flight instructor applicants upon request -- is to show that the recovery for this airplane is the same after 20 turns as it is after three turns. It also gives them a chance to see the engine (and prop) stopping under controlled conditions. This is a left spin; the 152 is reluctant to spin to the right.
There's the argument that stall/spin accidents occur at too low an altitude -- for example, below pattern altitude in the base-to-final turn -- for a successful recovery. This argument is valid, but the point is that at a safe, high altitude the student can see the conditions that lead to a spin and, therefore, may more readily recognize the onset at lower altitudes.
The "flat" turn to final from base has killed pilots over the years, and this too should be demonstrated at a safe altitude. When the airplane rolls and noses over, the student usually is amazed at the quick entry -- almost a snap -- with the nose suddenly pointed almost straight down. Since this maneuver takes about 600 feet of vertical altitude to affect a recovery, even when the pilot is expecting it, the result is eye-opening. It's a reminder not to "cheat" on that final turn by using a flat, skidding process.
When I was writing The Student Pilot's Flight Manual in 1959, I sent a copy of the manuscript to the FAA -- not to have those folks rewrite the book (the government text-books were the reason that I wrote my book) but to see if there were areas of flight training that I should hit harder (such as crosswind landings, etc.).
The reply that I got was interesting, because I was told that the opposite aileron being held in the process of that illegal, immoral, and dangerous skidding turn to final would result in that inside (down) aileron acting as a flap, not letting that wing stall. (It leads to a much earlier stall than the outside "reflexed aileron" wing.) The slower wing with the down aileron has a higher coefficient of lift; it will stall at a lower angle of attack and then will roll, putting it into a deeper stalled condition as it does so.
Since I was teaching this stall during the time I was writing the book, I didn't follow through with the suggestion to drop the chapter on advanced stalls. When the FAA's Flight Training Handbook came out 20 years later, I noticed a very familiar description of the skidding stall whose existence had been denied earlier!
Flight instructors tell me that skidding stalls should not be shown to fairly low-time pilots, because the stalls would frighten them. I disagree. If problems can happen in an airplane, pilots should be made aware of them.
A suggestion is that the turn from downwind to base be made at a 30-degree bank. This usually results in pilots saying that 30 degrees raises the stall speed too much. The stall speed of any airplane in a 30-degree bank is raised by a factor of 1.07, or 7 percent. This means that my airplane, which stalls at a calibrated airspeed of 41 kt, at maximum gross weight and 30 degrees (full) flaps at the most rearward center of gravity, would stall at a calibrated airspeed of 44 kt while in a 30-degree bank. The steeper bank will allow that turn to be completed and the wings leveled to check the runway and look for straight-in traffic. (I'm talking about high-wing airplanes in particular.)
As an example, let's say that through cross-control manipulations, the airplane is in a constant banked skidding turn to final. Because the airplane is not rolling it's assumed that for this 2,000-pound airplane each wing is producing 1,000 pounds of lift. Skipping part of the lift equation, look at CL (coefficient of lift) and V2 (velocity squared) for each wing.
The inside wing is slower and has a higher coefficient of lift to get the required 1,000 pounds of lift. The coefficient of lift is near its stall limit in making up for the slow speed on that side. Meanwhile, the outside wing is getting its 1,000 pounds of lift through a lower coefficient of lift and higher airspeed.
The attitude (banked and nose down) means that the inside rudder and drag of the down aileron are tending to "slice" the nose down, requiring conscious (or unconscious) application of back-pressure to the yoke or stick. The inside (down) wing will stall first, and the break and roll put it farther past the critical max of its CL versus angle-of-attack curve. It stalls, helped by the still-flying outside wing. If this occurs at traffic-pattern altitude, a successful recovery is unlikely.
I teach spins for two main reasons: The pilot should be aware of what could happen if he ignores the warning signs of stalls and imminent stalls that he learns in primary training (an airplane cannot enter a spin if it has not stalled). And, a conscientious and planned spin session with a properly certificated airplane and flight instructor can raise the confidence level of the low-time pilot. I've seen pilots who have been relieved to find that they could recover from the spin at a reasonable altitude. They've gone into an area of flying that had been unsettled in their mind since they started flying.
Are parachutes required for spin training for pilots other than CFI aspirants? The answer is no if the student, recreational, private, or commercial pilot is briefed and is instructed by a CFI for that purpose.
I was concerned about smaller, non-aerobatic flight schools, which normally do not keep parachutes packed for such instruction. It was no problem for me since I have an aerobatic school and keep current parachutes. So I wrote the FAA legal department and got an answer that said even though people had the lower certificates, if they wanted spin training in an appropriate airplane by a CFI, they did not need to wear parachutes because the federal aviation regulations require spin awareness training (and how better to become "spin aware" than in an airplane with an experienced CFI?).
However, if the CFI is flying along with a friend and decides on the spur of the moment to "show him a spin," parachutes are required.
In short, I would not advocate a return of the regulation that once required all pilots to get spin training, but I would suggest that if a flight school near you offers spin training, you should get a look at two- or three-turn spins and recoveries. It will increase your confidence in flying when you discover that the black pit you've been worried about is more gray than black.
William K. Kershner has been a flight instructor since 1949. He is the author of several books, including Student Pilot's Flight Manual, Advanced Pilot's Flight Manual, Instrument Flight Manual, Flight Instructor's Manual, and Logging Flight Time. The 1992 National Flight Instructor of the Year, he was inducted into the Flight Instructor Hall of Fame at Oshkosh in 1998. A specialist in spin entry and recovery, he teaches aerobatics in Sewanee, Tennessee. Visit his Web site.
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