80-17-07 SIKORSKY AIRCRAFT: Amendment 39-3877. Applies to S-61 series helicopters certificated in all categories, including military counterparts. Compliance required as indicated.
To prevent fatigue failures of the horizontal hinge pins: Replace the Rotary Wing Horizontal Hinge Pin P/N S6110-23020 and S6110-23320 prior to 4000 and 5300 hours time in service, respectively, or within 25 hours time in service after the effective date of this AD, whichever occurs later.
This amendment is effective August 15, 1980.