76-24-03 PRATT & WHITNEY AIRCRAFT: Amendment 39-2776. Applies to all Pratt & Whitney Aircraft JT9D turbofan engines containing fan blades, part numbers 658931, 718431, 726221, 734721, 735831, 735841, 740421, 740431, 740441, 740521, 741131, 741141, 748231, 748321, 748931, 750621, 750631, 758031, 758181, 758191, 758221, 760631, 760641, 760721, 760731, 760831, 760841, 760941, 761041, 761121, 761131, and 761141.
Compliance required as follows unless already accomplished.
To preclude failure of fan blades due to fatigue originating from undetected foreign object damage, inspect the critical areas of the blades in accordance with the procedures given in PWA ASB 4573, dated March 26, 1976, or later FAA approved revision, as follows:
1. Visually inspect all fan blades within the next 600 hours time in service after the effective date of this AD, and every 600 hours time in service thereafter.
2. Eddy current inspect all fan blades that have been previously damaged and blend repaired within the next 600 hours time in service after the effective date of this AD.
3. Eddy current inspect fan blades reworked per PWA Service Bulletins 4124 or 4262, without prior or subsequent damage or blend repairs, within the next 3500 hours time in service after the effective date of this AD.
If foreign object damage with a depth of .005 inch or more is found in the critical area, blend and inspect in accordance with Option 1 or Option 2 procedures given in PWA ASB No. 4573, dated March 26, 1976, or later FAA approved revision.
(NOTE: The AD does not change the present fan blade blend limits given in the JT9D engine manual.)
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 repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data tojustify the increase for that operator.
The manufacturer's specifications and procedures identified and described in this directive are 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 the New England Region.
This amendment becomes effective December 30, 1976.