The cabin pressure of an aircraft in flight is maintained at the selected altitude by?

The cabin pressure of an aircraft in flight is primarily maintained by controlling the rate at which air leaves the cabin. This involves the use of outflow valves that enable precise regulation of cabin pressure. When the aircraft ascends, the external pressure decreases, and the system must adjust to keep the cabin pressure stable, ensuring passenger and crew safety and comfort. By controlling the rate at which the air escapes the cabin, the system can effectively maintain the desired cabin altitude, even as the aircraft moves through varying external atmospheric pressures.

Increasing cabin air supply, adjusting the bleed air source, and monitoring external pressure are all components of the overall cabin pressure management system, but they do not directly maintain the pressure itself. Instead, they contribute to creating the conditions necessary for effective pressure control.