THE DOWNWIND TURN: AN OLD WIVES'TALE?

摘要

If you've ever flown a landing approach in gusty conditions, you've probably noticed momentary stall warning activation, even though your airspeed was well above stall. The rapidly changing relative wind is altering the wing's angle of attack, triggering the stall warning. You're experiencing wind shear. Wind shear is a difference in wind speed and/or direction over a relatively short distance. When the wind shears to a tailwind, the airplane momentarily loses airspeed and wants to pitch down. Its inertia relative to the shear determines how quickly it returns to its previous pitch angle and speed.