Airworthiness Directive 2012-19-11
one-timeAirworthiness Directives; The Boeing Company Airplanes
What this AD requires
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737 airplanes. This AD was prompted by a report of a flightcrew not receiving an aural warning during a lack of cabin pressurization event. This AD requires incorporating design changes to improve the reliability of the cabin altitude warning system by installing a redundant cabin altitude pressure switch, replacing the aural warning module (AWM) with a new or reworked AWM, and changing certain wire bundles or connecting certain previously capped and stowed wires as necessary. For certain airplanes, this AD also requires prior or concurrent incorporation of related design changes by modifying the instrument panels, installing light assemblies, modifying the wire bundles, and installing a new circuit breaker, as necessary. We are issuing this AD to prevent the loss of cabin altitude warning, which could delay flightcrew recognition of a lack of cabin pressurization, and could result in incapacitation of the flightcrew due to hypoxia (a lack of oxygen in the body), and consequent loss of control of the airplane.
Which aircraft AD 2012-19-11 applies to
Applicability limited to airplanes identified in Boeing Special Attention Service Bulletin 737-21-1164, Revision 1, dated May 17, 2012 (737-100/-200/-200C/-300/-400/-500 series) and Service Bulletin 737-21-1165, Revision 1, dated July 16, 2010, as revised by Revision 2, dated April 30, 2012 (737-600/-700/-700C/-800/-900/-900ER series).
Whether AD 2012-19-11 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.