Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Raytheon (Beech) Model 400A airplanes. This proposal would require replacement of certain bus bars connecting the battery and external power receptacle to the airframe ground with a new, improved bus bar. This proposal is prompted by reports of electrical arcing at the battery and external power receptacle of the airframe ground in the aft fuselage due to a deficiency in the bus bar and washer design. The actions specified by the proposed AD are intended to prevent overheating or arcing of the ground connection in the aft fuselage area, which could result in a fire hazard due to ignition of fuel fumes during an engine start sequence.