Which component primarily regulates cabin pressure by adjusting flow?

• A. Outflow valve
• B. Pack temperature sensor
• C. Bleed air shutoff valve
• D. Engine bleed control

Answer: (A)

The main idea is that cabin pressure is controlled by how much air is vented from the cabin to the outside. The outflow valve is the component that directly handles this, adjusting the flow to maintain the target cabin pressure. A cabin pressure controller takes readings from sensors and commands the valve to open or close, letting more air escape when needed or reducing venting to keep the pressure from dropping too low. The other components don't regulate cabin pressure by venting: the pack temperature sensor manages air cooling/heating, the bleed air shutoff valve isolates bleed air, and engine bleed control governs how much bleed air is available to the system.