Summary
The Federal Aviation Administration (FAA) proposes to supersede an existing airworthiness directive (AD), applicable to Rolls-Royce Deutschland Ltd & Co KG (RRD) (formerly Rolls-Royce plc) models Tay 650-15 and 651-54 turbofan engines with certain part numbers of fan blades and fan discs. That AD currently requires initial and repetitive visual and ultrasonic inspections of fan blades for cracks, and, if necessary, replacement with serviceable parts. In addition, that AD requires recording instances when engines are operated in a stabilized manner in newly prohibited ranges. This proposal would also require recording instances when engines are operated inadvertently in reverse thrust in prohibited ranges, and would require before further flight initial and repetitive ultrasonic inspections of fan blades for cracks and if necessary, dispositioning of fan blades and fan discs, if certain reverse thrust events occurred. This proposal is prompted by updated prohibited ranges of engine operation and the introduction of an N1 Alert System in Fokker Model F.28 Mark 0100 airplanes with Tay 650-15 engines installed. The actions specified by the proposed AD are intended to prevent fan blade failures, which can result in an uncontained engine failure, engine fire, and damage to the airplane.