Airworthiness Directives; Rolls-Royce plc RB211-524 Series Turbofan Engines

The FAA is superseding an existing airworthiness directive (AD) for Rolls Royce plc (RR) RB211-524 series turbofan engines with certain part number (P/N) intermediate pressure compressor (IPC) stage 5 disks installed. That AD currently requires new reduced IPC stage 5 disk cyclic limits. This AD requires the same reduced IPC stage 5 disk cyclic limits, requires removal from service of affected disks that already exceed the new reduced cyclic limit, and, removal from service of other affected disks before exceeding their cyclic limits using a drawdown schedule. This AD also exempts disks reworked to RR Service Bulletin (SB) No. RB.211-72-E182, Revision 1, dated July 30, 2004, and allows an on-wing eddy current inspection (ECI) on RB211-524G and RB211-524H series engines. This AD results from the manufacturer issuing a revised Alert Service Bulletin (ASB) to remove certain disks from applicability, and to allow an on-wing ECI on RB211-524G and RB211-524H series engines. We are issuing this AD to prevent failure of the IPC stage 5 disk, which could result in uncontained engine failure and possible damage to the airplane.