by Harold Green
Published in Midwest Flyer – October/November 2018 issue
A disproportionate number of loss-of-control accidents happen while turning from base to final caused by a stall spin accident. Typically, this is the result of overshooting the final approach course, steepening the turn and over applying rudder, resulting in a stall and a snap to spin. Perhaps a slight change in emphasis on airplane control could reduce this accident rate.
Over the years, training for the Private Pilot Certificate has been revised with the apparent goal of easing the path to completion. Years ago, an applicant was required to perform spins, chandelles, lazy eights and accelerated stalls, as well as pylon eight ground reference maneuvers in addition to the maneuvers required today. Further, instructors placed heavy emphasis on coordinated flight. If the ball got out of the cage during any maneuver other than a slip, there were sarcastic comments from the instructor. In the old tandem trainers, such as the Aeronca 7AC, where the instructor sat in the backseat, the point could well be driven home by a sharp rap alongside the student’s head. Further, most planes did not have coupled controls to assist in keeping the ball in its little cage. Students learned to maintain coordinated flight instinctively. In fairness, radio communications and electronic navigation were not included, so the time devoted to those today was not required back then.
There is also a difference in the airplanes we fly today, compared to the earlier years. The 7AC and the J-3 Cub could both bite if you entered a stall too enthusiastically or uncoordinated. Should you have a chance to fly a World War II trainer, such as the PT-22 or T-6, you will rapidly learn that aileron use in the stall is a definite no-no. If you compare the wings of these older planes with the newer Cessnas, Pipers or virtually any modern airplane, you will find that the designers have gone to great lengths to ensure that the stall progresses from the root outward, thereby causing the stall to be safer and more gentle. You really don’t want the wing to stall at the wingtips first because they probably won’t stall at the same time, particularly if the plane is slightly uncoordinated, and the leverage resulting will tend to flip the plane upside down.
Today, even the 310 hp Cirrus SR-22 is a pussycat in a full power stall thanks to the NASA derived airfoil. You may be lying on your back in the seat, but the stall tends to be a non-event. However, any of these planes will bite if you persist in non-coordinated flight or don’t promptly execute a stall recovery.
Today’s airplanes stall so gently that if the CG happens to be near the forward limit, the newbie may not even be aware that it has stalled. In fact, in many airplanes, again with forward CG, you can hold the plane in the stall with full up elevator, neutral aileron, and holding the heading with the rudders, the nose will bobble up and down, but will remain controllable, as long as you maintain coordinated flight.
A Skyhawk in a full flap stall will descend at about 1300 feet per minute. (Unless you are very accomplished, don’t try this without an instructor onboard, nor should you attempt it with the earlier model without the leading edge roll over of the later models or with the CG aft). That’s about the same rate that a Cirrus under the parachute descends: Of course, you have forward velocity with the Skyhawk that you don’t have with the Cirrus, and the airplane has not been designed to absorb kinetic energy in the same manner as a Cirrus, so this is not a recommended means of conducting an emergency landing.
It is still true, though, that if the pilot persists in uncoordinated use of rudder and aileron, or if he becomes too aggressive on the use of ailerons, the plane will bite. Over you go on your back and the ensuing spin is delightful to watch, from afar and at altitude.
We were all told at some point that a down aileron produces drag. If a stall occurs, a wing will often drop and the unaware pilot applies aileron to raise the wing usually without rudder input. That produces drag causing the plane to yaw in that direction with the result that the airflow over that wing slows causing it to stall further, while the other wing speeds up, causing it to generate more lift. The dirty side of the plane goes up and we begin the spin. For those unaware of it, that is the reason you were told to use rudder and not aileron in stall recovery. Today’s airplanes will permit use of aileron as long as you stay coordinated. By the way, the proper method of raising the wing that dropped in the stall is to use rudder. In today’s training, we say use coordinated rudder and aileron. However, just rudder will suffice in this condition and that is the way it used to be taught.
Now the point of this is that today’s airplanes are so forgiving and gentle in the stall that they can very easily lull the unwary pilot into complacency regarding the dangers of an inadvertent stall. There are some folks who feel that better trainers would be ones which scares the student into respecting the stall. While this could produce the desired result, the unintended consequences would probably be a reduction in the number of students completing training or even beginning training. Perhaps a preferred approach would be to increase emphasis on coordinated flight, stall recovery and stall avoidance.
As a further point on this issue, reference to the Nall report (published annually by the AOPA Air Safety Foundation, which presents accident statistics in a very organized manner), reveals that so long as the aircraft remains under control, the chances of surviving an accident are tremendously improved over loss of control. Thus, the primary goal of the pilot during any emergency should be to maintain control of the aircraft. A saving grace is that today’s airplanes, properly flown, will recover from a stall with remarkably little loss of altitude, assuming the pilot recognizes the stall immediately.
More emphasis on maintaining coordinated flight would seem to be in order here. All too often pilots just don’t use the rudder. The idea that when the throttle goes forward, so should the right rudder for most engines, seems to escape many pilots. In fairness, the longer since the pilot was last checked, the worse the performance is. Also, when the plane is pitched up, the rudder should be applied also because the P-factor comes into play here. NOTE: If you have an engine with opposite rotation to U.S. engines, the left rudder becomes dominant.
Another aspect of controlled flight, particularly in the landing pattern, is the fact that for a given power setting, pitch attitude determines the airspeed. Yes, if you have more power than you need for that attitude, the plane will climb. In the landing pattern when you reduce power, the airplane will assume a speed determined by the pitch attitude of the plane. In fact, with most airplanes a full reduction in power while holding the pitch attitude level will result in an airspeed remarkably close to the best glide speed for the plane. The point is that while in the pattern and at a fixed power setting, you can hold airspeed by holding attitude. A fact that some people don’t seem to accept.
You certainly don’t have to stare at the airspeed indicator once you have established your speed. It is only necessary to maintain the pitch attitude that established the speed. This permits you to pay greater attention to the ground track. The problem comes about when the pilot seeing the airplane is too low tends to raise the nose. This only results in the plane landing shorter than before and could result in a stall. The proper response is to add power and keep airspeed constant by managing the pitch. This not only results in a safer landing, but a better landing as well. Remember, the stabilized approach concept?
Should a stall occur on the turn to final, proper recognition and reaction will result in rapid recovery from the stall. Many of today’s airplanes, particularly the lighter planes which make up the majority of the loss-of-control pattern accidents, are capable of recovery from a stall with considerably less than a 500 ft loss. That means that providing the airplane is coordinated at the time of the stall, there is an excellent chance of safe, if scary, recovery. Perhaps during training, we should place emphasis on stall recovery with a minimum loss of altitude.
In summary, what is suggested here is that a renewed emphasis on the very basic elements of airplane control seems to be in order. It is not possible, nor is it desirable, to return to the ways of yore. However, some renewed emphasis on the fundamentals of aircraft control can’t hurt and probably would result in increased safety.
EDITOR’S NOTE: Harold Green is an Instrument and Multi-Engine Instrument Instructor (CFII, MEII) at Morey Airplane Company in Middleton, Wisconsin (C29). A flight instructor since 1976, Green was named “Flight Instructor of the Year” by the Federal Aviation Administration in 2011 and is a recipient of the “Wright Brothers Master Pilot Award.” Questions, comments and suggestions for future topics are welcomed via email at email@example.com, or by telephone at 608-836-1711 (www.MoreyAirport.com).
DISCLAIMER: The information contained in this column is the expressed opinion of the author only, and readers are advised to seek the advice of their personal flight instructor and others, and refer to the Federal Aviation Regulations, FAA Aeronautical Information Manual and instructional materials before attempting any procedures discussed herein.