Airworthiness Directive · Amendment 39-16476 · Hydraulic power
McDonnell Douglas Corporation Model MD-90-30 Airplanes
This AD applies to McDonnell Douglas Corporation Model MD-90-30 airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin MD90-29A021, Revision 2, dated March 16, 2010.
We are superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires modifying the auxiliary hydraulic power system (including doing all applicable related investigative and corrective actions). This new AD requires these same actions, using corrected service information. This AD was prompted by fuel system reviews conducted by the manufacturer, as well as reports of electrically shorted wires in the right wheel well and evidence of arcing on the auxiliary hydraulic pump power cables, which are routed within the tire burst area. We are issuing this AD to prevent electrically shorted wires or arcing at the auxiliary hydraulic pump power cables, which could result in a fire in the wheel well. We are also issuing this AD to reduce the potential of an ignition source adjacent to the fuel tanks, which, in combination 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 18 months after the effective date of this AD, modify the auxiliary hydraulic power system, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-29A021, Revision 2, dated March 16, 2010. Do all applicable related investigative and corrective actions before further flight.
