Airworthiness Directive · Amendment 39-10407 · Boeing Model 747-400 Series Airplanes
Boeing Model 747-400 Series Airplanes
Model 747-400 series airplanes; as listed in Boeing Alert Service Bulletin 747-25A3137, dated March 13, 1997; certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes, that requires a one-time inspection of the separation between the galley power feeder and static ground wiring, and the adjacent passenger oxygen system tubing in the forward ceiling area above the door 4 galley; and rerouting of wiring, and installing clamps and sleeves, if necessary. This amendment is prompted by reports of inadequate clearance between the galley power feeder wiring and passenger oxygen system tubing. The actions specified by this AD are intended to prevent such inadequate clearance, which could result in a fire in the ceiling area above the door 4 galley due to chafing of wiring on oxygen system tubing.
