What is the procedure to re-engage the A/THR after an A/THR disconnect?

What is the procedure to re-engage the A/THR after an A/THR disconnect?

• A. Move the thrust levers to CL detent, then press the A/THR pb on the FCU.
• B. Press the A/THR pb on the FCU, then move the thrust levers to the CL detent.
• C. Turn on the A/THR circuit breaker.
• D. Push the AP button.

Answer: (B)

Re-engaging auto thrust after a disconnect requires both re-arming the A/THR function on the FCU and placing the thrust levers in the climb detent. The A/THR pushbutton on the FCU re-enables autothrust, but it will not take control unless the throttle levers are in the CL detent, signaling that you want autothrust to manage thrust for the current flight phase. Once you press the A/THR pushbutton and then move the thrust levers to the climb detent, autothrust can couple and control N1 to meet the selected speed. Turning on the A/THR circuit breaker alone doesn’t re-arm autothrust, and pressing the AP button re-engages the autopilot, not the autothrust.

Re-engaging auto thrust after a disconnect requires both re-arming the A/THR function on the FCU and placing the thrust levers in the climb detent. The A/THR pushbutton on the FCU re-enables autothrust, but it will not take control unless the throttle levers are in the CL detent, signaling that you want autothrust to manage thrust for the current flight phase. Once you press the A/THR pushbutton and then move the thrust levers to the climb detent, autothrust can couple and control N1 to meet the selected speed.

Turning on the A/THR circuit breaker alone doesn’t re-arm autothrust, and pressing the AP button re-engages the autopilot, not the autothrust.