How many stall protection computers exist and what do first/second activations do?

• A. Two; one activation triggers stick shaker; the other triggers stick pusher
• B. Two; both activations trigger stick shaker
• C. One; activation triggers stick shaker
• D. Three; one triggers stick shaker; others do nothing

Answer: (A)

Stall protection is designed with redundancy and two activation stages. There are two stall protection computers. The first activation triggers the stick shaker, which gives a tactile warning to the pilot by vibrating the control column. If the stall threat continues and reaches the next threshold, the second activation engages the stick pusher, which automatically moves the control column forward to reduce angle of attack and prevent a stall. This two-step approach provides an early warning plus a protective intervention, while the dual computers ensure the system remains functional if one path or component is compromised.