Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This proposed AD was prompted by reports of electrical shorts of the motor stator wiring burning a hole through the housing of the motor of the cabin air compressor (CAC). This proposed AD would require installing modified inboard and outboard CAC modules on the left side and right side cabin air conditioning and temperature control system (CACTCS) packs. We are proposing this AD to prevent an electrical short from burning through the housing of the motor of the CAC, which could result in a fire in the pack bay, and consequent reduced controllability of the airplane.