After takeoff, what action normally engages the A/THR mode?

After takeoff, what action normally engages the A/THR mode?

• A. Move the thrust levers to MAX
• B. Engagement of the A/THR switch
• C. Press TOGA
• D. Engage N1 limit

Answer: (B)

Autothrust is the system that automatically manages engine thrust to maintain the desired speed and margins during flight. After takeoff, it is normally activated by turning the A/THR switch to ON, enabling the autothrust to control N1 (thrust) to follow the commanded speed from the flight director or autopilot. Moving the thrust levers to maximum simply selects takeoff thrust but does not by itself engage automatic thrust control. Pressing TOGA sets the thrust reference for takeoff, but autothrust engagement occurs with the A/THR switch, not just by selecting TOGA. Engaging an N1 limit is a protective parameter, not the action that enables automatic thrust control.

Autothrust is the system that automatically manages engine thrust to maintain the desired speed and margins during flight. After takeoff, it is normally activated by turning the A/THR switch to ON, enabling the autothrust to control N1 (thrust) to follow the commanded speed from the flight director or autopilot.

Moving the thrust levers to maximum simply selects takeoff thrust but does not by itself engage automatic thrust control. Pressing TOGA sets the thrust reference for takeoff, but autothrust engagement occurs with the A/THR switch, not just by selecting TOGA. Engaging an N1 limit is a protective parameter, not the action that enables automatic thrust control.