67-28-04: Compressor Disc

67-28-04 GENERAL ELECTRIC ENGINES: Amdt. 39-489 Part 39 Federal Register October 5, 1967. Applies to Type CJ805-3, 3A, 3B, 23, 23B and 23C Turbojet Engines. Compliance required as indicated. To prevent failure of the eighth stage compressor disc P/N 106R682P1 and 108R619P1 accomplish the following: (a) Remove from service eighth stage compressor discs with 12,000 or more cycles on the effective date of this AD within the next 50 cycles. (b) Remove from service eighth stage compressor discs with 11,000 or more cycles on the effective date of this AD within the next 250 cycles. (c) Remove from service eighth stage compressor discs with less than 11,000 cycles but more than 9500 cycles on the effective date of this AD within the next 600 cycles. (d) Remove from service eighth stage compressor discs with less than 9500 cycles on the effective date of this AD within the next 1250 cycles or at 8000 cycles, whichever occurs later. (e) Remove from serviceeighth stage compressor discs installed into engines on or after the effective date of this AD at or before 8000 cycles. (f) For the purpose of this AD, the number of cycles equals the number of flights that involve an engine operating sequence consisting of engine starting, take off operation, landing, and engine shutdown. The number of cycles may be determined by actual count or, subject to acceptance by the assigned FAA Maintenance Inspector, may be calculated by dividing each eighth stage compressor disc's time in service by the operator's fleet average time per flight (involving an engine operating sequence consisting of engine starting, take off operation, landing and engine shutdown). (General Electric Alert Service Bulletins A72-254 and A72-261 cover the same subject.) This amendment effective October 5, 1967.