The Federal Aviation Administration has proposed relaxing oxygen-mask requirements for pilots in pressurised aircraft, including Part 91 and Part 135 operations. The notice of proposed rulemaking would lift the two-pilot Part 135 threshold from flight level 350 to FL410, raise the single-pilot threshold from FL250 to FL350, and let Part 91 crews with quick-donning masks operate at any certified altitude without continuously wearing a mask.
The proposal follows a mandate in the FAA Reauthorization Act of 2024 and would revise long-standing cockpit oxygen rules for commuter, on-demand and general aviation flights. For Part 91 aircraft without quick-donning masks, the existing requirement above FL350 would remain in place. The agency declined to extend the lone-pilot threshold to FL410, citing the limited time a pilot can remain conscious at that altitude if cabin pressure is lost.
The changes are still subject to public comment, which closes on 23 November 2026. Until the FAA issues a final rule, current oxygen-mask requirements remain in force.