Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 series airplanes. This proposal would require a general visual inspection of wiring behind the control panel of the auxiliary power unit (APU) located in the cockpit to detect chafing; repair if necessary; and modification of the wiring. This proposal is prompted by an incident of chafing of wire bundles of the control module of the APU. The actions specified by the proposed AD are intended to prevent such chafing and resultant arcing due to insufficient clearance between the wire bundles and the airplane structure, which could result in smoke and fire in the flight deck.