76-03-02 SIKORSKY AIRCRAFT: Amendment 39-2507. Applies to S-61L, S-61N, S- 61NM, and S-61R helicopters certified in all categories including Military CH-3C, HH-3C, CH- 3E, and HH-3E helicopters using NAS 577-10 or NAS 577-10A barrel nuts for attaching the transmission main gearbox to the fuselage structure.
Compliance required as indicated.
To prevent fractures in the attaching nuts accomplish the following:
Remove the NAS 577-10 or NAS 577-10A barrel nuts and replace with RMLH 2577-108 barrel nuts within the next 30 days after the effective date of this AD, unless already accomplished. (NOTE: Sikorsky Service Bulletin No. 61B35-36B covers this subject.)
This supersedes Amendment 39-2202 (40 FR 24355), AD 75-12-13.
This amendment becomes effective February 17, 1976.