Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain McDonnell Douglas transport category airplanes. The existing AD currently requires modification of the installation wiring for the electric motor-operated auxiliary hydraulic pumps in the right wheel well area of the main landing gear; repetitive inspections of the numbers 1 and 2 electric motors of the auxiliary hydraulic pumps for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage; and corrective actions if necessary. This proposed AD would, for certain airplanes, also require modifying and rerouting, as applicable, certain components of the wiring of the electric motor for the auxiliary hydraulic pump located in the right wheel well. This proposed AD results from reports of failure of the electric motor for the auxiliary hydraulic pump. We are proposing this AD to prevent failure of the electric motors of the hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure.