78-08-13 PRATT & WHITNEY AIRCRAFT: Amendment 39-3195 as amended by Amendment 39-3710. Applies to all Pratt & Whitney Aircraft Models JT9D-3, -3A, -7, -7A, -7H, -7AH, -7F, and -7J turbofan engines.
Compliance required as indicated, unless already accomplished.
To prevent main gearbox fires due to internal bearing failures, perform the following in accordance with the provisions of Pratt & Whitney Alert Service Bulletin 4854 dated March 27, 1978, or later FAA approved revision:
1. All gearboxes having more than 5,000 hours time in service since new or more than 5,000 hours time in service since the last bearing inspection, in accordance with the JT9D Engine Manual, P/N 646028, Section 72-09-50, must have the magnetic plug inspected within the next 300 hours time in service after the effective date of this AD, and every 300 hours time in service thereafter.
2. All gearboxes having 5,000 hours or less time in service since new or 5,000 hours or less time in service since the last bearing inspection, in accordance with the JT9D Engine Manual, P/N 646028, Section 72- 02-50, must be inspected with either (a) or (b) whichever occurs earlier:
a. Within the next 650 hours and every 650 hours thereafter until a total gearbox time of 5,000 hours has been accumulated.
b. At a total gearbox time of 5,300 hours.
3. If metal particles (spalled pieces), as defined in Paragraph 2A of Alert Service Bulletin 4854, are found on the magnetic plug, perform the following:
Reinspect the magnetic plug within the next 50 hours time in service:
a. If no additional spalled particles are found resume the repetitive inspection of paragraph 1 or 2 as applicable.
b. If spalled particles are found, reinspect within the next 25 hours time in service.
(1) If no additional spalled particles are found resume the repetitive inspection of paragraph 1 or 2 as applicable.
(2) If spalled particles are found, remove the gearbox from service prior to further flight.
Upon request of the operator, an equivalent method of compliance with the requirements of this AD may be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, New England Region.
Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, New England Region, may adjust the repetitive inspection interval 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 specifications and procedures identified and 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 the Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts, 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.
Amendment 39-3195 became effective upon publication in the Federal Register.
This amendment 39-3710 becomes effective April 18, 1980.