Summary
The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to Honeywell International Inc. (formerly AlliedSignal) model RE220 (RJ) auxiliary power units (APUs) part number (P/N) WE3800770-2. This proposal would require replacing the existing fuel nozzles with new design fuel nozzles, making reidentification updates to the APU identification plate, and operating the APU to perform a visual inspection for fuel leaks. This proposal is prompted by reports received by the FAA of cracks occurring in the existing APU fuel nozzles leading to fuel leaks. The actions specified by the proposed AD are intended to prevent APU compartment fires and fuel vapor explosion.