Airworthiness Directive Proposed for Cessna 500 and 600 Series A/C Motor

The FAA proposes an airworthiness directive for the Cessna 500, 501, 550, 551, S550, 560, 560XL and 650 prompted by multiple reports of smoke and/or fire in the tailcone caused by sparking due to excessive wear of the brushes in the air-conditioning (A/C) motor. The proposed AD would require an inspection to determine the accumulated hours on certain A/C drive motor assemblies; repetitive replacement of the brushes in the drive motor assembly or, as an alternative to brush replacement, deactivation of the air conditioner; and the return of replaced brushes to Cessna.