On a door exit, when does the cabin pressure warning light illuminate?

• A. Engines are off, cabin is still pressurized, the door is disarmed
• B. Engines are running, cabin depressurized, the door is armed
• C. Engines are off, cabin depressurized, the door is disarmed
• D. Engines are running, cabin pressurized, the door is disarmed

Answer: (A)

The thing being tested is how the door exit warning system signals a pressurization situation during ground operations. The cabin pressure warning light on a door exit lights up when the cabin is still pressurized while the aircraft is not actively maintaining that pressure with the engines running, and the door is in the disarmed state. In this condition, opening the door could release pressure unexpectedly, so the warning alerts the crew to be cautious.

That’s why the best choice is engines off, cabin still pressurized, and the door disarmed. If engines are running, cabin pressure is actively controlled and the warning isn’t required. If the cabin is depressurized, there’s no pressurization hazard to warn about. If the door were armed, the situation and risk are different, so the warning wouldn’t be triggered in the same way.