76-08-01 R1 SIKORSKY AIRCRAFT: Amendment 39-2581 as amended by Amendment 39- 4006. Applies to Sikorsky S-61L helicopters prior to and including Serial No. 61454, and S-61A, S-61D, S-61E, and S-61V helicopters.
Compliance required as indicated.
To prevent possible separation of the tail rotor pylon due to cracks in the pylon hinge fittings, accomplish the following:
(a) Within 30 hours' time in service after the effective date of this AD, unless already accomplished within the last 120 hours' time in service, and thereafter at intervals not to exceed 150 hours' time in service from the last inspection, inspect the upper and lower pylon hinge fitting assemblies, P/N S6120-66117-0 and -2, and P/N S6120-66120-0 and -2, in accordance with Section 2, Paragraphs B and A (1) of Sikorsky Service Bulletin No. 61B20-13C, dated November 12, 1980, or later FAA approved revisions, or in accordance with equivalent methods approved by the Chief, Engineering and Manufacturing Branch, New England Region.
(b) If a crack is found around the edge of the bushings in the lug or in the shaded area shown in Detail B, Figure 1, of the above service bulletin, replace the fitting prior to further flight.
(c) If a crack is found on the flat surface of the alignment pad, and the crack is below the limits of Detail B, Figure 1, of the above Sikorsky Service Bulletin or later FAA approved revisions, rework to remove the crack in accordance with Section 2, Paragraph C, of the above Sikorsky Service Bulletin or later FAA approved revisions or in accordance with an equivalent method approved by the Chief, Engineering and Manufacturing Branch, New England Region. If the crack is beyond the limits of Detail B, Figure 1, replace the fitting prior to further flight.
(d) If it is found that contact has been made between the fitting and the lug alignment pad, or less than 0.010 inch clearance exists in this area, perform a rework and inspection of the fittings, prior tofurther flight, in accordance with Section 2, Paragraph C of the above Sikorsky Service Bulletin or later approved revisions, or in accordance with equivalent methods approved by the Chief, Engineering and Manufacturing Branch, New England Region.
The manufacturer's 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 Sikorsky Aircraft, Stratford, Connecticut 06602. These documents may also be examined at FAA, 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 FAA, New England Region Headquarters, Burlington, Massachusetts.
This AD supersedes Amendment 39-1921 (39 F.R. 28975), AD 74-17-06.
Amendment 39-2581 became effective April 30, 1976.
This amendment 39-4006 becomes effective December 29, 1980.