AD 76-12-06

76-12-06 PRATT & WHITNEY AIRCRAFT: Amendment 39-2639. Applies to all Pratt and Whitney Aircraft JT8D-9, -11, -15 and -17 engines containing second stage fan blade pin, P/N 520456, rivet, P/N 520457, and bushing, P/N 520458.

Compliance required as indicated unless already accomplished.

A. To preclude liberation of second stage fan blades, inspect the blade pin rivet, P/N 520457, for loss of head or for missing bushing, P/N 520458, in accordance with P&WA Service Bulletin No. 4577 dated April 26, 1976, or later FAA approved revision or equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region, prior to the accumulation of 1200 hours time in service since new blade pin rivets were installed or within the next 300 hours time in service after the effective date of this AD, whichever is later. Inspect thereafter at intervals not exceeding 600 hours time in service since the last inspection. Remove engines from service with failed second stage fan blade pin rivets before further flight.

B. Remove from service second stage fan blade pin, P/N 520456, rivet, P/N 520457, and bushing, P/N 520458, and replace with pin, P/N 758242, and rivet, P/N 760187, or other FAA parts prior to January 1, 1979.

The manufacturer's service bulletin 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 and Whitney Aircraft, 400 Main Street, East Hartford, Connecticut 06108. These documents may also be examined at the Office of the Regional Counsel, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and at Federal Aviation Administration Headquarters, 800 Independence Avenue, S.W., Washington, D.C. 20591. A historical file on this AD which includesthe incorporated material in full is maintained by the Federal Aviation Administration at its headquarters in Washington, D.C., and at the New England Regional Office in Burlington, Massachusetts.

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.

This amendment becomes effective thirty days after publication in the Federal Register.