What is the normal cabin differential pressure?

What is the normal cabin differential pressure?

• A. 8.5 psi
• B. 9.0 psi
• C. 10.2 psi
• D. 11.0 psi

Answer: (C)

Cabin differential pressure is the difference between the air pressure inside the cabin and the air pressure outside the aircraft, maintained by the pressurization system to keep the cabin environment comfortable and within the aircraft’s structural limits. For this aircraft, the normal operating differential is 10.2 psi. This value keeps the cabin altitude in the comfortable range (roughly a few thousand feet) during cruise while staying within the fuselage’s design limits. If the differential were lower, the cabin altitude would rise and comfort would suffer; if it were higher, the pressure loads on the fuselage could approach or exceed safe limits, risking structural stress. The other options fall outside the standard operating point, so 10.2 psi is the best representation of normal operation.

Cabin differential pressure is the difference between the air pressure inside the cabin and the air pressure outside the aircraft, maintained by the pressurization system to keep the cabin environment comfortable and within the aircraft’s structural limits. For this aircraft, the normal operating differential is 10.2 psi. This value keeps the cabin altitude in the comfortable range (roughly a few thousand feet) during cruise while staying within the fuselage’s design limits. If the differential were lower, the cabin altitude would rise and comfort would suffer; if it were higher, the pressure loads on the fuselage could approach or exceed safe limits, risking structural stress. The other options fall outside the standard operating point, so 10.2 psi is the best representation of normal operation.