Airworthiness Directives; Rolls-Royce plc (RR) RB211-535E4 Series Turbofan Engines

The FAA is superseding an existing airworthiness directive (AD) for RR RB211-535E4 series turbofan engines. That AD currently requires initial and repetitive inspections of the outer combustion case for cracks and possible removal if cracks are found. This AD requires the same inspections, but requires using RR Mandatory Service Bulletin (MSB) RB.211-72-7775, Revision 3, dated April 9, 1999. This AD results from the FAA approving Revision 3 to the MSB, which adds an alternative eddy current inspection (ECI) method. We are issuing this AD to prevent an uncontained outer combustion case burst, which could result in damage to the airplane.