AD 76-24-01

76-24-01 PRATT & WHITNEY AIRCRAFT: Amendment 39-2775 as amended by Amendment 39-2910. Applies to all Pratt & Whitney Aircraft JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, and -11 turbofan engines containing eighth stage compressor disk, P/N 496908.

Compliance required as indicated.

To prevent possible failure, remove from service the eighth stage compressor disk, P/N 496908 in accordance with the following schedule:

A. After June 30, 1977, remove disks prior to accumulating 8,000 cycles since new. In lieu of removal, disks may be continued in service until December 31, 1977, if inspected in accordance with Pratt & Whitney Aircraft Special Instruction No. SI-10F-77 by June 30, 1977, and every 120 cycles thereafter. Cracked disks shall be replaced prior to further flight. The established life limit of 11,000 cycles shall not be exceeded.

B. After September 30, 1977, remove disks prior to accumulating 6,000 cycles since new. In lieu of removal, disks may be continued in service until December 31, 1977, if inspected in accordance with Pratt & Whitney Aircraft Special Instruction No. SI-10F-77 by September 30, 1977, and every 120 cycles thereafter. Cracked disks shall be replaced prior to further flight. The established life limit of 11,000 cycles shall not be exceeded.

After December 31, 1977, P/N 496908 compressor disk retirement life is 6,000 cycles since new.

Upon request of the operator, an FAA Maintenance Inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator.

The manufacturer's Special Instruction No. SI-10F-77 identified and described in this directive is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Pratt & Whitney Aircraft, Division of United Technologies Corporation, 400 Main Street, East Hartford, Connecticut 06108. These documents may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its Headquarters in Washington, D.C., and at New England Region.

Amendment 39-2775 became effective 30 days after publication in the FEDERAL REGISTER.

This amendment 39-2910 becomes effective on June 22, 1977.