Which component is directly involved in regulating cabin pressure by venting air to the atmosphere?

Which component is directly involved in regulating cabin pressure by venting air to the atmosphere?

• A. Outflow valve
• B. Ground valve
• C. APU door
• D. Thrust reverser

Answer: (A)

Regulating cabin pressure is achieved by venting air overboard through the outflow valve. This valve, controlled by the cabin pressure regulator, adjusts how much air escapes to maintain the target cabin altitude. When the sensed cabin pressure climbs above the setpoint, the regulator opens the outflow valve more to vent excess air; when the pressure is too low, it closes the valve to retain air. This direct venting to the atmosphere is what keeps the cabin pressure within the desired range. The other components don’t handle this function: the APU door relates to the auxiliary power unit’s airflow, thrust reversers are used for braking and deceleration during landing, and a ground valve isn’t part of the in-flight pressurization control loop.

Regulating cabin pressure is achieved by venting air overboard through the outflow valve. This valve, controlled by the cabin pressure regulator, adjusts how much air escapes to maintain the target cabin altitude. When the sensed cabin pressure climbs above the setpoint, the regulator opens the outflow valve more to vent excess air; when the pressure is too low, it closes the valve to retain air. This direct venting to the atmosphere is what keeps the cabin pressure within the desired range.

The other components don’t handle this function: the APU door relates to the auxiliary power unit’s airflow, thrust reversers are used for braking and deceleration during landing, and a ground valve isn’t part of the in-flight pressurization control loop.