At 72 kt, which statement describes ground spoiler behavior when armed and wheel speed exceeds 72 kt?

At 72 kt, which statement describes ground spoiler behavior when armed and wheel speed exceeds 72 kt?

• A. As soon as both thrust levers are idle
• B. As soon as reverse is selected on one engine
• C. Only when commanded by the flight crew
• D. They do not extend automatically

Answer: (A)

Ground spoilers act as lift-dump devices that automatically extend when the system is armed and the airplane is on the ground. The wheel-speed signal (above 72 kt) confirms contact with the surface, so the control logic allows the spoilers to deploy. Once both thrust levers are moved to idle, the system recognizes the landing configuration and extends the ground spoilers immediately to dump lift and aid braking. This happens without needing a manual command or any input from reverse thrust.

Ground spoilers act as lift-dump devices that automatically extend when the system is armed and the airplane is on the ground. The wheel-speed signal (above 72 kt) confirms contact with the surface, so the control logic allows the spoilers to deploy. Once both thrust levers are moved to idle, the system recognizes the landing configuration and extends the ground spoilers immediately to dump lift and aid braking. This happens without needing a manual command or any input from reverse thrust.