You remember, or should, that an airplane stalls when the angle of attack, the difference between the chord line and the relative wind, exceeds something on the order of 17 degrees. The chord line is a line drawn from the leading edge to the trailing edge of the wing. That’s maybe a bit more technical than we need. The angle of attack is simply the difference between where the airplane is going and where the relative wind is coming from. It’s important to understand that, although the relative wind is exactly opposite the direction of flight, the direction of flight is not necessarily where the airplane’s nose is pointing. It doesn’t matter how fast or slow the airplane is going, whether it’s climbing or diving or even if it’s flying inverted. And therein lies the rub! If the angle of attack is more than the critical angle, the airplane will stall.
Some pilots — to their dismay — have had trouble accepting the fact that an airplane will stall at any airspeed and in any attitude. This lack of acceptance has caused more than a few pilots not to recognize why buzzing can have dire consequences. Picture this: You’re diving toward sunbathers on the beach. In the dive the angle of attack is relatively low. But then, when you reach the bottom of the dive and begin to raise the nose, the airplane is still moving toward the ground but with the nose raised. The angle of attack has increased — despite how fast you’re going — and when the difference between the chord line and the relative wind exceeds the critical angle of attack, the airplane will stall — and likely much more violently than you’ve previously experienced. Unfortunately, without sufficient altitude to recover from the stall, you’re now stuck between the laws of aerodynamics and a hard place. You’ll more than likely make a bigger splash than you’d intended.
Concentrating on sunbathers can be distracting, but there are many more mundane operations that can also be distracting. An interruption during a preflight inspection can lead to missed items. A disruption during an approach to landing has been the cause of a number of gear-up landings. A distraction during maneuvering flight — the sunbathers on the roof of the dorm during an approach to Morristown Airport, a request to check another airplane’s landing gear or an attempt to take air-to-ground photos — all can be the precursor to a stall/spin accident. When we think about it, the potential for distractions is ramped up when we’re in the pattern getting ready to land. We’re busy watching for traffic, setting the flaps, changing power settings, lowering the gear, adjusting the prop, checking fuel on the fullest tank, planning the approach, talking on the radio and checking the windsock.
With all the distractions in the pattern, it’s not surprising a lot of stall/spin accidents occur close to the ground. A typical scenario involves a cross-control stall that often occurs when a pilot, turning base to final, flies through the extended centerline and, instead of abandoning the approach and performing a go-around, steepens the bank while adding back pressure or tries to “rudder” the airplane back toward the centerline. The resulting cross-control stall will be too close to the ground to recover.
When distractions raise heads, airmanship is the skill we use to prevent a stall and the possibility of a subsequent spin. With the advent of moving maps, autopilots and other technological aids, airmanship is suffering. In a sense, as instructors we’re to blame, since as our students begin instrument training we admonish them to ignore the sensations they get from their senses and fly the instruments. But that applies only when there’s no visible horizon; at other times, “flying by the seat of the pants” still prevails!