FAA Proposes Relaxing Part 135 and 91 Oxygen Mask Rules

Pilots of pressurized aircraft would be able to fly at any certified altitude without supplemental oxygen if quick-donning masks are available.

Jack Daleo

Tuesday, September 29, 2026 at 01:00 PM ET

Verified

Edited By:

Zach Vasile

Evolution of aircraft design and low rate of pressurization failures at high altitude prompted FAA to review its existing oxygen mask requirements for Parts 135 and 91. [Credit: NBAA]

Key Takeaways:

The FAA has proposed new rules to relax oxygen mask requirements for pilots in Part 135 and Part 91 operations, aiming to save operators millions annually without compromising safety.
This relaxation is justified by advancements in modern aircraft pressurization and warning systems, a low incidence of high-altitude decompression events, and aligns existing regulations more closely with international standards.
Key changes include raising oxygen mask thresholds for Part 135 operations (e.g., two-pilot quick-donning mask from FL350 to FL410) and exempting Part 91 pilots in pressurized aircraft with quick-donning masks from wearing them at any certified altitude.

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The FAA has proposed a new rule that would relax oxygen mask requirements for Part 135 and 91 operations, arguing that the changes would save operators millions of dollars annually without adversely affecting safety.

In a notice of proposed rulemaking (NPRM) published last week, the agency said the new rule would raise the altitudes at which at least one pilot at the controls must wear and use an oxygen mask during Part 135 commuter and on-demand operations. It would also permit Part 91 pilots of pressurized aircraft to fly at any certified altitude without a mask, if quick-donning masks are available. Comments on the proposal are due November 23.