How to prevent the stall/spin scenario
Aircraft are much safer now than when the Wright brothers first flew in 1903, although stall/spin accidents still comprise 10 percent of all accidents—and just under 14 percent of fatal accidents. According to AOPA Air Safety Institute studies on accidents during the period 1991 through 2000, 91 percent of stall/spin accidents occurred with an instructor on board during dual instruction. Something’s definitely wrong here.
Studies show that the group most likely to have stall/spin accidents are private and commercial pilots, not students or ATPs. Unfortunately, while many studies and articles are loaded with facts and figures about stall/spin accidents, they seldom address what actually causes them. And it is not the lack of spin training—at least, not the type of spin training most people receive. This is clearly illustrated by the fact that flight instructors are the only pilots required to get a spin endorsement, yet they are still being surprised—with tragic results.
Aerobatic training is no guarantee you won’t encounter an inadvertent stall and spin an airplane. Traditional spin-recovery training (nose up, stall, full opposite rudder) won’t prevent stall/spins, either. These exercises deal with maneuvering the airplane in a deliberate fashion, aimed at performing maneuvers or intentionally inducing a spin as a training exercise. They don’t prevent the typical stall/spin accident because they don’t address what causes them.
By the time most airplanes have been allowed to fully enter a spin, the total altitude required to then recover will be in excess of 1,000 feet. This is a proven fact, and another way of saying that, if you really do enter a spin at pattern altitude, you won’t have enough altitude to safely recover—regardless of your spin experience.
Is it important to know how to recover from a developed spin? Yes! Will it save you in an accidental stall/spin in the pattern? Probably not. But it’s better than nothing.
The root cause of stall/spin accidents is poor flying skills. Period. When such an episode happens, the individual has committed two major sins at the same time: First the speed was allowed to degrade, and second, this was done while the ball was way off center. Not a little off center, but way off center. These are both significant mistakes that not only are totally preventable, but actually shouldn’t happen if you fly as you were taught to fly when you had 10 hours and were about to solo. This is very basic stuff.
One of the basic precepts of good flying is that you keep the turn coordinator’s ball in the middle. We all know that. But how many of us actually make that a goal every time we’re in the airplane? Judging by the stall/spin statistics, not enough.
There are two people to blame when an effort is not being made to keep the ball dead center as much as possible: the instructor and the pilot. It’s the flight instructor’s job to push the basics—including keeping the ball in the center. Unfortunately, we aren’t doing that job very well. Efficient flying requires that the airplane always be free of yaw (except when intentionally slipping), otherwise it’s not going where it should be going. And the airplane is wasting lots of energy as it tries to wedge its way through the air, as opposed to cleanly slicing through it.
The instructor knows that and should be constantly monitoring and advising the student, from the first lesson to the final checkride prep flight, to keep the ball in the center. This is the only way a student pilot is going to become a pilot who has an innate understanding and appreciation of yaw control.
One of the forgotten aspects of yaw control is that the ball is simply a graphic representation of something your butt already knows. When an airplane yaws, it tries to move the pilot slightly sideways in the seat, which results in unbalanced pressure on the buttocks. If it is yawing left, the butt feels as if it is trying to move right and the right side feels more pressure. The ball indicates that yaw by moving to the right. So, you bring equilibrium to your posterior by applying pressure to the right rudder pedal, in the same way you “step on the ball” to center it.
If the pilot has even the slightest familiarity with the sensations associated with the ball being off-center, he won’t have to look at the panel to know he needs to apply rudder—or which pedal to press. If he does that, he will have eliminated the potential for the “spin” portion of the stall/spin accident because an airplane absolutely will not spin if the ball is even close to being in the center.
Now, all a pilot has to worry about is the “stall” portion. One of the difficulties with preventing stalls is that they are usually practiced in ways that have little to do with the way accidental stalls happen in the real world. In training, the nose is pulled well above the horizon, there is some shuddering, some pushing, and power added. That’s not the way they happen in real life.
Almost any airplane in approach configuration, especially something such as a Cessna that has a lot of flap available, does not need to have its nose pulled dramatically above the horizon to stall. The critical angle of attack—where the wing decides it has had enough and stops flying—isn’t measured from level ground. It is measured from the path on which the airplane is traveling. On an approach, the path of flight is down, meaning the relative wind is coming from a low angle. So reaching the critical angle of attack may not even mean bringing the nose up to the horizon—much less above it. All it needs to do is to drift slowly upward; the speed will bleed off to a dangerous level long before the nose gets to the horizon.
Most stall/spin accidents on approach include a chain of events: The pilot inadvertently overshoots the base-to-final turn and needs to turn sharply back to get on final. He rolls into a bank, but instinctively knows he shouldn’t have a lot of bank close to the ground. So, to stop the bank, he cranks a little aileron against the bank, at the same time standing on a little inside rudder to make the nose continue in the turn, literally pulling the airplane around with his inside foot. The airplane is turning left, but right aileron is being held. This aileron forces the ball to the outside of the turn while, at the same time, down aileron on the left (inside) wing is effectively asking that wing to give more lift—guaranteeing that, if a stall occurs, it will happen to the inside wing first.
The inside (left) rudder also drives the ball to the right, further compounding the yaw already being caused by holding right aileron. So the airplane is skidding through the turn with the ball hard to the outside. While all of this is going on, both the ball and the pilot’s rear end are sliding to the right, practically crying for right rudder—or, at the very least, relaxing of the right aileron.
To tighten up the turn, the pilot adds some back pressure to help keep the nose coming around the corner and to keep it from falling. The stall speed has already gone up because of the increased bank and the cross-controlled configuration. Then, if the pilot doesn’t notice the nose drifting slowly upward, the stage is set for disaster: Because of the skid and the bank angle, the airplane will decelerate faster than normal—and at a nose attitude that doesn’t begin to approximate the outlandishly high angles seen while practicing stalls at altitude. Both the pilot sliding right and the nose coming up indicate what’s going to happen next.
As the stall breaks, the left wing loses its lift first and the airplane rolls toward the rudder that is down. It rolls left, over the top, into the early stages of a spin entry. If this happens during the base-to-final turn, the airplane is generally so low, 500 to 700 feet above the ground, that it doesn’t actually have enough altitude to enter a developed spin, but it is still very nose down and rolling on impact.
At that altitude, when the stall breaks, the pilot has few options. If, as the airplane starts to flick over the top, he immediately hammers both the power and the stick forward, and gets lots of rudder against the roll, he has a chance of breaking the stall and stopping the rotation. Then, if there’s enough altitude he can roll level, hopefully before the ground fills his windshield. Everything depends on the pilot’s instantaneously realizing what is happening and reacting to it.
None of the foregoing need ever happen. If the pilot is aware of his nose or his butt (or the ball)—or, better yet, all three—and he’s cross-checking his airspeed, he’ll never come close to these kinds of transgressions. Stall/spin accidents are the single most preventable accident in aviation. All we need to do is fly the way we were taught on our earliest flights, when the basics were still fresh in mind.