AD FAA-2026-3873

The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus SAS Model A330-200 and A330-300 series airplanes modified by a certain supplemental type certificate (STC). This proposed AD was prompted by a finding that, for airplanes with a flightcrew oxygen system supplied by a single oxygen cylinder, the oxygen supply would be insufficient under all circumstances for extended operations (ETOPS) with a with a maximum diversion time of 180 minutes (ETOPS-180) with four flightcrew members. This proposed AD would require revising the existing Airplane Flight Manual Supplement (AFM-S) to limit ETOPS-180 operations to three flightcrew members, as applicable, and correct minimum oxygen dispatch pressure information. The FAA is proposing this AD to address the unsafe condition on these products.