FAA proposes easing oxygen mask requirements for Part 91 and 135 flights

The FAA has proposed loosening the oxygen mask rules for Part 135 commuter and on-demand flights and for Part 91 operations. The agency says the change would save operators millions of dollars a year without costing safety.

Published as a notice of proposed rulemaking, the proposal would raise the altitudes at which at least one pilot at the controls must wear and use a mask during Part 135 commuter and on-demand flying. Under Part 91, pilots of pressurized aircraft could fly at any certified altitude without a mask, as long as quick-donning masks are on board.

For Part 135, the two-pilot quick-donning mask threshold would go from FL350 to FL410, and the single-pilot threshold from FL250 to FL350.

The FAA defines a quick-donning mask as one that can be donned with one hand within five seconds, without removing eyeglasses, delaying emergency duties or interrupting normal communications.

The agency says its current rules are stricter than International Civil Aviation Organization standards. It cites better pressurization and warning systems in modern aircraft, along with the rarity of high-altitude pressurization failures. In a review of more than 20 million flight hours above FL250 by Part 91 and Part 135 operators, the agency counted 200 decompression events, only a quarter of them above FL410.

Raising the servicing thresholds would cut regulatory and economic costs for Part 91 and Part 135 fleet operators, according to the notice, which puts oxygen servicing at between $100 and $400 per fill. Comments are due November 23.