Airworthiness Directives; Rolls-Royce Deutschland Ltd. & Co. KG (RRD) Models Tay 650-15 and Tay 651-54 Turbofan Engines

요약

We propose to supersede an existing airworthiness directive (AD) for Tay 650-15 turbofan engines. That AD currently requires initial and repetitive inspections of the low-pressure (LP) turbine discs stage 2 and stage 3 for corrosion, on certain Tay 650-15 serial number engines. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Strip results from some of the engines listed in the applicability section of this AD revealed excessively corroded low-pressure turbine disks stage 2 and stage 3. The corrosion is considered to be caused by the environment in which these engines are operated. Following a life assessment based on the strip findings it is concluded that inspections for corrosion attack are required. The action specified by this European Aviation Safety Agency (EASA) AD 2008-0122 was intended to avoid a failure of a low- pressure turbine disk stage 2 or stage 3 due to potential corrosion problems which could result in uncontained engine failure and damage to the airplane. It has been