PRODUCT: All Rolls-Royce plc (RR) RB211-524 series turbofan engines. SUBJECT: Airworthiness Directive 2013-04-01 ACTION: Final Rule
SUMMARY: The FAA is superseding an existing airworthiness directive (AD) for the product listed above. That AD currently requires removal and repair of certain thrust reverser units (TRUs) prior to reinstallation. This AD requires the same actions for an expanded population of TRUs and extends the compliance time for repairing certain TRUs. This AD was prompted by additional engineering evaluation of TRUs, as a result of a translating cowl gearbox stubshaft failure and subsequent repair.
The FAA is issuing this AD to prevent failure of the attachment rivets, which may result in release of the TRU from the engine.