Airworthiness Directives; AlliedSignal Aerospace GTCP85 Series Auxiliary Power Units

Özet

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to AlliedSignal Aerospace (formerly Garrett Auxiliary Power Division and Garrett Turbine Engine Co.) GTCP85 series auxiliary power units (APU). This proposal would require modifying the APU to install an exhaust centerbody. This proposal is prompted by reports of two uncontained APU failures where turbine wheel fragments exited the APU exhaust axially and damaged the aircraft. The actions specified by the proposed AD are intended to prevent an axially uncontained APU failure and damage to the aircraft.