Airworthiness Directive E7-5556
one-timeAirworthiness Directives; Boeing Model 737-300, -400, -500, -600, -700, -800 and -900 Series Airplanes; and Model 757-200 and -300 Series Airplanes
What this AD requires
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-300, -400, -500, -600, -700, -800 and -900 series airplanes; and Model 757-200 and -300 series airplanes. This AD requires modifying the activation mechanism in the chemical oxygen generator of each passenger service unit (PSU). This AD results from several reports indicating that some chemical oxygen generators failed to activate during in-flight decompression events. These failures were due to fracture of components between the passenger oxygen mask and the release pin in the oxygen generator. We are issuing this AD to prevent failure of the activation mechanism in the chemical oxygen generator, which could result in the unavailability of supplemental oxygen and possible incapacitation of passengers and cabin crew during an in- flight decompression.
Which aircraft AD E7-5556 applies to
Whether AD E7-5556 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.