Airworthiness Directives; The Boeing Company Airplanes

FAA / Federal Register · 2020-02667

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 707 airplanes and Model 720 and 720B series airplanes. This AD was prompted by the FAA's analysis of the Model 707 and 720 fuel system reviews conducted by the manufacturer. This AD requires modifying the fuel quantity indicating system (FQIS) to prevent development of an ignition source inside the center fuel tank due to electrical fault conditions. The FAA is issuing this AD to address the unsafe condition on these products.