Action
Final rule.
Summary
The FAA is superseding Airworthiness Directive (AD) 2020-12- 01, which applied to certain Rolls-Royce Deutschland Ltd. & Co KG (RRD) Trent XWB-75, Trent XWB-79, Trent XWB-79B, and Trent XWB-84 model turbofan engines. AD 2020-12-01 required initial and repetitive inspections of the low pressure compressor (LPC) outlet guide vane (OGV) outer mount ring assembly and, depending on the results of the inspections, possible replacement of the LPC OGV outer mount ring assembly. Since the FAA issued AD 2020-12-01, the FAA determined that these inspections are also necessary for RRD Trent XWB-97 model turbofan engines. This AD was prompted by analysis by the manufacturer of the LPC OGV assembly and LPC OGV outer mount ring assembly which predicted that when the front engine mount is in the fail-safe condition, the most highly stressed LPC OGV assembly has a life that could be substantially less than one shop visit interval. This AD requires initial and repetitive inspections of the LPC OGV outer mount ring assembly and, depending on the results of the inspections, replacement of the LPC OGV outer mount ring assembly, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference (IBR). The FAA is issuing this AD to address the unsafe condition on these products.