Action
Final rule; request for comments.
Summary
We are superseding airworthiness directive (AD) 2014-05-25 for all Rolls-Royce plc (RR) RB211-Trent 970-84, RB211-Trent 970B-84, RB211-Trent 972-84, RB211-Trent 972B-84, RB211-Trent 977-84, RB211- Trent 977B-84, and RB211-Trent 980-84 turbofan engines. AD 2014-05-25 required inspections of the low-pressure turbine (LPT) exhaust case and support assembly or tail bearing housing (TBH) to detect cracks or damage. This AD modifies the inspection schedule for the affected engines and adds an optional terminating action. This AD was prompted by RR performing additional analysis of inspection results and determining that the existing inspections need to be modified. We are issuing this AD to correct the unsafe condition on these products.