Which control mode provides fully automatic pressurization without pilot input?

• A. Automatic controller
• B. Semi automatic
• C. Manual
• D. Emergency mode

Answer: (A)

In aircraft pressurization, the mode that maintains cabin pressure automatically without pilot input uses an automatic controller. This controller continuously uses sensor data (cabin altitude and differential pressure) and the programmed pressure schedule to adjust the outflow valve and bleed air automatically. It handles changes in flight altitude and maintains the target cabin altitude and safe differential pressure without the pilot having to intervene.

Manual mode requires the pilot to control the valve directly. Semi-automatic means some settings require pilot input or confirmation. Emergency mode is a degraded, automatic backup that keeps the system safe but with limited automatic control. So the automatic controller is the one that provides fully automatic pressurization.