56-02-03 ROLLS-ROYCE: Applies to All Dart 506 and 510 Engines.
Compliance required as indicated.
Due to the possibility of low stage compressor impeller failure, all impellers, P/N's RK13782, RK17877, RK19795, RK20156 and RK20181, must be removed from service and not reused after a maximum of 725 hours service time, except that when Rolls-Royce Modifications 335 and 348 have been accomplished the maximum service time may be increased to 750 hours.
The British Air registration Board considers this parts replacement program mandatory and the FAA concurs.
Operation beyond 750 hours total time is not authorized.