To what flight level are single pack operations limited?

Single pack operations are limited to Flight Level 250. This limitation is established to ensure passengers and crew maintain adequate cabin pressure and comfort during flight. Operating above this altitude with only one pack can compromise the aircraft’s ability to pressurize the cabin effectively, increasing the risk of oxygen deprivation for those onboard.

In the case of the CRJ 200, the aircraft is designed to operate efficiently with its two environmental control packs, but in scenarios where only one pack is functioning, the operational ceiling is set at FL 250 to manage thermal and cabin pressure conditions. Beyond this altitude, the demands on the remaining pack may exceed its capacity, which can lead to safety issues related to cabin pressurization.

Thus, the established operational ceiling for single pack operations is set at FL 250, ensuring that the aircraft operates within safe limits.