Summary
This document proposes to revise an existing airworthiness directive (AD) applicable to BMW Rolls-Royce GmbH (BRR) Models BR700- 710A1-10 and BR700-710A2-20 turbofan engines. The existing AD currently requires initial and repetitive visual inspections of the engine compressor and combustion core fairings (also referred to as the engine core fairings) and fasteners for correct installation and damage, and verification that the engine core fairing fasteners are torqued to a higher torque value. This action would increase the repetitive inspection interval to 150 hours time-in-service (TIS) following an initial inspection and follow-on inspection at the current 50 hours TIS interval. This action also would require an initial inspection and follow-on inspection at a 50 hours TIS interval following any engine core fairing or fastener removal, repair, or replacement. Repair of engine core fairings has been added as an alternate to engine core fairing replacement, and an inspection for loose engine core fairing(s) has been included to verify correct installation on the engine. This proposal is prompted by results of repetitive inspections that indicate that the inspection interval can be increased safely. The actions specified by the proposed AD are intended to prevent engine compressor or combustion core fairing detachment and damage to the engine bypass duct, resulting in engine failure and damage to the airplane.