Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes

Özet

We are adopting a new airworthiness directive (AD) for certain Boeing Model 747-400, 747-400D, and 747-400F series airplanes. This AD requires installing an extension tube to the existing pump discharge port of the scavenge pump on the outboard side of the center fuel tank in the main fuel tank 2. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent a fire or explosion in the fuel tank and consequent loss of the airplane.