When the MAX APU DOOR light is illuminated on the ground, what does this indicate?

When the MAX APU DOOR light is illuminated on the ground, what does this indicate?

• A. APU door is not in the ground position
• B. APU door is in the ground position
• C. APU door is open in flight
• D. APU door is closed on the ground

Answer: (A)

The APU DOOR light is a door-position indicator for the inlet door. On the ground, the door should be in the closed ground position to protect the APU and reduce drag. If that light is illuminated, it means the door is not in the ground (fully closed) position. This could be due to the door not fully closed, being jammed or misaligned, or a faulty position sensor. Do not assume the door is properly closed; resolve or verify the position before starting or taxiing. The other possibilities describe the door being in the ground position, open in flight, or closed on the ground, which don’t fit the observed illuminated indication on the ground.

The APU DOOR light is a door-position indicator for the inlet door. On the ground, the door should be in the closed ground position to protect the APU and reduce drag. If that light is illuminated, it means the door is not in the ground (fully closed) position. This could be due to the door not fully closed, being jammed or misaligned, or a faulty position sensor. Do not assume the door is properly closed; resolve or verify the position before starting or taxiing. The other possibilities describe the door being in the ground position, open in flight, or closed on the ground, which don’t fit the observed illuminated indication on the ground.