Is the Autobrake system operable when the alternate brakes are active?

Is the Autobrake system operable when the alternate brakes are active?

• A. Yes
• B. AutoBrake with alternate brakes
• C. Autobrake operates in limited mode
• D. No

Answer: (D)

Autobrake depends on the normal brake hydraulics and its control logic to automatically apply a predefined deceleration during landing or rollout. When alternate brakes are selected, the system switches to the standby (alternate) hydraulic circuit and the autobrake logic is inhibited because it cannot rely on the primary pressure and sensor signals. So, autobrake cannot operate with alternate brakes active. You can still brake manually, but the automatic braking schedule is not available in this condition.

Autobrake depends on the normal brake hydraulics and its control logic to automatically apply a predefined deceleration during landing or rollout. When alternate brakes are selected, the system switches to the standby (alternate) hydraulic circuit and the autobrake logic is inhibited because it cannot rely on the primary pressure and sensor signals. So, autobrake cannot operate with alternate brakes active. You can still brake manually, but the automatic braking schedule is not available in this condition.