Airworthiness Directive · Amendment 39-14685 · Boeing Model 737-200, -300, and -400 Series Airplanes
Boeing Model 737-200, -300, and -400 Series Airplanes
This AD applies to Boeing Model 737-200, -300, and -400 series airplanes, certificated in any category, equipped with auxiliary fuel tanks.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-200, -300, and -400 series airplanes. This AD requires replacing the existing fueling float switch in the auxiliary fuel tank with a new, improved fueling float switch, installing a new liner system inside the float switch conduit, and performing related investigative and other specified actions. This AD results from reports of chafing of the direct-current-powered float switch wiring insulation in the center fuel tank. We are issuing this AD to prevent contamination of the fueling float switch of the auxiliary fuel tank by moisture or fuel, and chafing of the float switch wiring against the float switch conduit in the fuel tank, which could present an ignition source inside the fuel tank that could cause a fire or explosion.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 24 months after the effective date of this AD: Replace the existing fueling float switch in the auxiliary fuel tank with a new, improved fueling float switch, install a new liner system inside the float switch conduit, and perform related investigative and other specified actions, by doing all of the actions in accordance with Part A of the Accomplishment Instructions of Boeing Service Bulletin 737-28A1192, Revision 2, dated April 27, 2006.
Note 1: This AD does not require doing the actions in Part B of the Accomplishment Instructions of Boeing Service Bulletin 737-28A1192, Revision 2, dated April 27, 2006.
As of the effective date of this AD, no person may install a fueling float switch having P/N F8300-146 on the auxiliary fuel tank of any airplane.
Replacements and conduit liner system installations accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737-28A1192, dated March 27, 2003; or Boeing Service Bulletin 737-28A1192, Revision 1, dated August 21, 2003; are acceptable for compliance with the requirements of this AD.
