Summary
The FAA proposes to supersede 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 proposed AD would require the same reduced IPC stage 5 disk cyclic limits, the requirement to remove from service affected disks that already exceed the new reduced cyclic limit, and to remove from service other affected disks before exceeding their cyclic limits using a drawdown schedule. This proposed AD also would exempt disks reworked to RR Service Bulletin (SB) RB.211-72-E182, Revision 1, dated July 30, 2004, and would allow an on-wing eddy current inspection (ECI) on RB211-524G and RB211-524H series engines. This proposed 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 proposing this AD to prevent failure of the IPC stage 5 disk, which could result in uncontained engine failure and possible damage to the airplane.