Summary
The FAA proposes to adopt a new airworthiness directive (AD) for Boeing Model 727 airplanes equipped with an auxiliary fuel tank having a fuel pump installed. This proposed AD would require revising the airplane flight manual to include limitations on operating the fuel pumps for the auxiliary fuel tank. This proposed AD is prompted by a design review of the fuel pump installation, which revealed a potential unsafe condition related to the auxiliary fuel tank(s). We are proposing this AD to prevent dry operation of the fuel pumps for the auxiliary fuel tank, which could create a potential ignition source inside the auxiliary fuel tank that could result in a fire or explosion of the auxiliary fuel tank.