Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) airplanes and Model MD-88 airplanes. This proposal would require a general visual inspection for chafing of the power feeder cables of the auxiliary power unit (APU), and repair if necessary. This proposal also would require replacement of a support bracket located on the left side of the lower cargo compartment with a new "U" shaped bracket. This action is necessary to prevent chafing of the power feeder cables of the APU, which could result in electrical arcing to adjacent structure and consequent fire in the airplane. This action is intended to address the identified unsafe condition.