Airworthiness Directives; The Boeing Company Airplanes

FAA / Federal Register · 2019-27885

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 727 airplanes. This AD was prompted by the FAA's analysis of the Model 727 fuel system review conducted by the manufacturer. This AD requires modifying the fuel quantity indicating system (FQIS) to prevent development of an ignition source inside the body-mounted auxiliary fuel tanks due to electrical fault conditions. As an alternative to the modification, this AD allows deactivating the body-mounted auxiliary fuel tanks. The FAA is issuing this AD to address the unsafe condition on these products.