Learning to stall or unstall an aircraft is for the most part a rather mechanical task. You could probably train a chimp to do it. Pull on the control wheel to stall – Push to recover. Right? In the world of flight instruction and airman certificate requirements it becomes a variation on a theme. The student does this in various configurations: take-off and departure stalls, approach to landing stalls, accelerated stalls, etc. The stalls are performed under anticipated and controlled circumstances, at safe altitudes, with the objective of perfecting the techniques sufficiently to accomplish yet another of the many check ride tasks. It is a rare instructor who can impress upon a student the significance of stalls in real world flying above and beyond the training requirements. Even experienced pilots may not understand the practical implications as the subject relates to accident potential and survivability.
In 20 years of aircraft accident investigation I have truly come to appreciate that the difference between stalling and not stalling an airplane can literally be the difference between life and death. I have personally investigated accidents where pilots have walked away from aircraft crashes in rugged mountains and forests because the pilot continued to “fly the airplane” right up to the point of impact. Conversely, I have been involved in several aircraft accident investigations in which people were killed or seriously hurt because the pilot prematurely stalled the aircraft even though the plane could have landed relatively unscathed on terrain which was flat and obstruction-free.
Imagine that you are in cruise in a single engine plane and have a complete power loss. Gravity politely requests that you commence a descent. You are a hundred feet above terra firma that does not look good and descending. The airspeed is getting slow and there is a natural tendency to want to avoid the inevitable by pulling back on the stick. Let ‘s freeze-frame right here because you can see where this is going. We are on the verge of a stall. The moment the plane stalls, it pitches steep nose down and the rapid vertical descent will be sharply arrested by slamming into the ground nose first. Recovery is an impossibility. The engine will be pushed in to where the instrument panel was, but it will be of little consequence since the vertical g-force of the instant deceleration at impact was fatal to the occupants.
Okay, let’s try this another way. You maintain flying speed. You fly through trees and other nasty things. The airplane sheds parts, but the momentum is forward and the impact during horizontal deceleration is slower and much more tolerable on the human body than the vertical drop which occurs in a stall. There are no guarantees as to survivability in this scenario, but it offers a chance where stalling a plane at low altitude offers none. If you don’t believe me, I’ve got the pictures to prove it.
More prevalent than engine failures are accidents involving density altitude take-offs. Again, I’ve seen both sides of the coin under identical circumstances. Pilot A maintains control of the plane and either runs off the runway or makes an off airport landing when he realizes that flying is not an option and walks away. Pilot B tries to force the plane to climb or avoid obstructions by increasing the pitch attitude until a stall occurs at which point the plane pitches nose down and hits the ground killing all on board. Stalling at as little as 50′ above the ground or even less is all it takes and it happens in the blink of an eye.
Then there are the stalls that really sneak up on you. You are turning base to final and you start to overshoot the extended centerline of the runway. You are already low and slow, but now you want to get aligned with the runway in a hurry and so you crank in the aileron to steepen the turn. One second you are flying and then the next you are in an accelerated stall heading down. Maybe you have enough altitude to recover (in theory), but with the ground rushing up at you, pushing forward on the control wheel to recover is not going to be a natural reaction.
Any maneuvering at a low altitude exposes you to stall potential especially when a pilot is distracted by other events. There have been a number of cases of fatal stall accidents in the traffic pattern simply because the pilot took off with an unlocked cabin or baggage door and became so distracted by the noise that he forgot to fly the airplane even though the open door had no aerodynamic effect. Other distractions can relate to low-altitude sight -seeing, looking for other traffic, or problem passengers. When we fly near the ground, we perceive a false illusion of speed, so that we may not visually consider just how slow the airplane is going unless we cross-check with the airspeed indicator.
It does not matter whether you are a student or high time pilot, stalls are more than just an academic subject or training regimen. It is not enough to know what stalls are and how to recover. You need to be cognizant of those flying situations where you may go from flying to falling. Consider a refresher session with a qualified CFI on learning more about potential stall traps as well as stall recognition characteristics for the plane you fly. Remember, above all, “Fly-The-Plane” and don’t be a chimp.
Editor’s Note: This article was written by Ken Steiner prior to his retirement from the United States Aircraft Insurance Group as a Vice-President and Claims Manager. During his career, Ken investigated thousands of aircraft accidents involving small planes, crop dusters, helicopters, corporate aircraft, and airliners. He has been on-site at over 100 fatal aircraft accident investigations. He is currently an Aviation Investigative Consultant and is also a Pilot and Tactical Flight Officer for the San Mateo County Sheriff’s Air Support Unit. He owns a Cessna 182 based at San Carlos and holds ATP and CFI certificates with over 5000 flying hours.