Airworthiness Directive 04-19855
one-timeAirworthiness Directives; Boeing Model 737-600, 737-700, 737-700C, 737-800, and 737-900 Series Airplanes
What this AD requires
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-600, 737-700, 737-700C, 737-800, and 737-900 series airplanes, that requires measuring the electrical resistance of the support bracket for the fire extinguisher bottle located in the left main landing gear wheel well to ensure that it does not exceed the maximum allowed resistance; and corrective actions, if necessary. This action is necessary to prevent high electrical resistance in the squib firing circuit, which could result in insufficient electrical current to fire the fire extinguisher bottle squib and discharge the fire extinguishing agent, which could lead to an uncontrolled engine fire. This action is intended to address the identified unsafe condition.
Which aircraft AD 04-19855 applies to
Whether AD 04-19855 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.