Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-81, -9-82, -9-83, and -9-87 series airplanes; Model MD-88 airplanes; and Model MD-90-30 series airplanes. This proposal would require repetitive inspections of the number 1 and 2 electric motors of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/voltage; and corrective actions, if necessary. This action is necessary to prevent various failures of electric motors of the auxiliary 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. This action is intended to address the identified unsafe condition.