FAA Airline Transport Pilot (ATM)Transport Aerodynamics and High-Altitude OperationsMedium
A transport aircraft's stall protection system incorporates two distinct devices: one vibrates the control column to alert the pilot as angle of attack approaches the critical value, and the other automatically pushes the control column forward if angle of attack continues to increase toward a preset threshold. These devices are respectively known as:
- AStick shaker and stick pusher
- BAngle of attack indicator and overspeed warning horn
- CYaw damper and Mach trim system
- DAutothrottle and autopilot
Show answer & explanationAnswer & explanation
Correct answer: A. Stick shaker and stick pusher
The stick shaker is a tactile/aural stall warning that vibrates the control column as AOA approaches the stall, while the stick pusher is an automatic control input that forcefully moves the column forward to reduce AOA if the shaker warning is ignored and AOA continues to rise toward the critical value.
Why the other options are wrong
- B. AOA indicators display data but don't shake the column; overspeed warning addresses excess speed, not stall.
- C. Yaw damper and Mach trim address yaw oscillation and pitch trim at high Mach, not stall.
- D. Autothrottle/autopilot control thrust and flight path, not stall protection.
Stick Shaker / Stick Pusher
Stall protection devices: the stick shaker vibrates the control column as a warning near the stall AOA; the stick pusher automatically moves the column forward to reduce AOA if the critical value is reached.
- Stick shaker = tactile/aural warning
- Stick pusher = automatic corrective control input
- Both triggered by AOA sensors, not just airspeed
- Common on transport-category swept-wing jets
Memory trick: Shaker shouts 'wake up!'; pusher shoves the nose down for you