Airworthiness Directive · Amendment 39-9921 · The Boeing Company Airplanes
The Boeing Company Airplanes
This AD applies to The Boeing Company MD-11, MD-11F.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment supersedes an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 and MD-11F series airplanes, that currently requires, among other things, repetitive visual inspections to detect discrepancies of the fuel pipe of the fuel transfer system of the tail tank and associated mounting bracket located in the aft fuselage compartment. That AD was prompted by reports of cracking or bending of the fuel pipe mounting support and/or attaching bracket in the aft fuselage compartment due to a fuel pressure surge that caused repetitive loading of this area. This amendment adds a requirement to install a restraint on the tail tank fuel pipe, which would terminate the repetitive visual inspections. The actions specified by this AD are intended to prevent such cracking/bending, which could expose the fuel pipe coupling O-ring. An exposed O-ring could lose its sealing effect and could allow a fuel leak in the aft fuselage compartment, which would present a fire hazard.
