EASA AD 2020-0059
SUPERSEDED BY EASA AD 2022-0237
Summary
EASA Airworthiness Directive 2020-0059 is an airworthiness directive addressing Rolls-Royce Deutschland Ltd & Co KG RB211-524 series engines installed on Boeing 747 and Boeing 767 aircraft. It focuses on the low pressure turbine (LPT) Stage 1 discs with specific part numbers, requiring life reduction and removal from service of affected parts to prevent potential disc failure.
What Changed
This directive introduces a life reduction for certain reworked LPT Stage 1 discs due to findings that some engines may have operated beyond the approved flight profile limits. It mandates removal of affected parts before they reach the new declared safe cyclic limit and prohibits installation of parts exceeding these limits.
Why It Matters
This AD is critical for aviation professionals as it addresses a safety risk that could lead to engine in-flight shutdown and release of high-energy debris, potentially causing damage and loss of aircraft control. Operators and maintenance organizations must ensure compliance to maintain aircraft airworthiness and avoid unsafe engine operation.
What To Do
Operators must remove affected LPT Stage 1 discs from service before they reach the new safe cyclic limits or within 25 flight cycles after 31 March 2020, whichever is later. Installation of affected parts is only allowed if they have not exceeded the new limits, and affected parts must be replaced with serviceable ones as specified. Compliance with Rolls-Royce NMSB RB.211-72-AK422 Revision 1 is required.
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