Airworthiness Directive · Amendment 39-15073 · McDonnell Douglas Model MD-11 and MD-11F Airplanes
McDonnell Douglas Model MD-11 and MD-11F Airplanes
This AD applies to all McDonnell Douglas Model MD-11 and MD-11F airplanes; certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all McDonnell Douglas Model MD-11 and MD-11F airplanes. This AD requires installing bracket assemblies and jumper wires in the center main wheel well to improve the bonding path between the structure (wall) of the lower auxiliary fuel tank and its internal fuel pumps; measuring the electrical resistance between the fuel pump housings and the fuel tank structure; and doing corrective actions if necessary. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to detect and correct an inadequate bond between the internal fuel pump housings and the structure of the lower auxiliary fuel tank. This condition, if not corrected, could fail to meet fault current requirements and result in a potential ignition source that, in combination with flammable fuel vapors, could cause a fuel tank explosion and consequent loss of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 60 months after the effective date of this AD, do the actions described in paragraphs (f)(1) and (f)(2) of this AD, in accordance with the Accomplishment Instructions of Boeing Service Bulletin MD11-28-127, dated September 19, 2006.
(1) Install bracket assemblies and jumper wires between the structure of the lower auxiliary fuel tank and its internal fuel pumps.
(2) Do an electrical resistance measurement between the fuel pump housings and the lower auxiliary fuel tank wall.
If any resistance measurement done in accordance with paragraph (f)(2) of this AD is greater than 2.5 milliohms on either fuel pump housing: Before further flight, rework the electrical bonding between the fuel pump housings and the lower auxiliary fuel tank wall as needed to achieve a resistance measurement of 2.5 milliohms or less on both fuel pump housings, in accordance with the Accomplishment Instructions of Boeing Service Bulletin MD11-28-127, dated September 19, 2006.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
