Airworthiness Directive · Amendment 39-15921 · Fuel
McDonnell Douglas Model MD-90-30 Airplanes
This AD applies to McDonnell Douglas Model MD-90-30 airplanes, certificated in any category, excluding fuselage number 2159.
We are adopting a new airworthiness directive (AD) for certain McDonnell Douglas Model MD-90-30 airplanes. This AD requires installing fuses and wire protection in certain wing and fuel tank spars. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent possible damage to the fuel level float or pressure switch wires. Such damage could become a potential ignition source inside the fuel tank, and, when combined with flammable fuel vapors, could result in 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 5 years after the effective date of this AD, do the actions specified in paragraph (g)(1) or (g)(2) of this AD, as applicable, in accordance with the Accomplishment Instructions of Boeing Service Bulletin MD90-28-012, dated November 19, 2008 (“the service bulletin”).
(1) For Group 1 airplanes identified in the service bulletin, install fuel level float switch in-line fuses and wire protection in the left and right wing forward spars and center fuel tank forward spar, right side.
(2) For Group 2 airplanes identified in the service bulletin, install fuel level float switch in-line fuses and wire protection in the left and right wing forward spars, center fuel tank forward spar, right side, and forward auxiliary fuel tank, right side; and install a fuel pressure switch in-line fuse and wire protection in the center fuel tank forward spar, left side.
