Oxygen masks deploy in Normal mode at approximately what cabin altitude?

• A. 14,600 ft
• B. 14,800 ft (±200 ft)
• C. 14,000 ft
• D. 15,000 ft

Answer: (B)

Oxygen masks are tied to a cabin altitude sensor, and the system is set to deploy automatically when the cabin altitude reaches a specific threshold in Normal mode. For the Longitude in Normal mode, that trigger is about 14,800 ft, with a tolerance of ±200 ft. This means deployment can occur roughly between 14,600 and 15,000 ft. The reason for this fixed threshold is to provide oxygen quickly if pressurization is lost or if the cabin rises toward higher altitudes, while avoiding nuisance drops during normal cruising where cabin altitude is kept well below this limit.