AD 67-29-05

67-29-05 SIKORSKY AIRCRAFT: Amdt. 39-501 Part 39 Federal Register November 1, 1967. Applies to type S61 Helicopters.

Compliance required as indicated.

To prevent fatigue failures of the Rotary Wing Hub Horizontal Hinge Pins, P/N S6100-23020 and P/N S6110-23320, accomplish the following:

(a) Within the next 10 hours' time in service after the effective date of this AD, unless already accomplished, inspect the horizontal hinge pins in accordance with Sikorsky Service Bulletin No. 61B10-4 dated August 21, 1967 or later revisions approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Eastern Region. Equivalent inspections may be approved by an FAA maintenance inspector.

(1) If a machining defect is found on the interior surface of the cylindrical part of the pin or on the inner surface of the part of the pin where the damper is attached (sections 1 or 3 of the pin as defined in the Sikorsky Service Bulletin) remove the hingepin from service prior to further flight.

(2) If a machining defect is found on the interior surface of the tapered part of hinge pin (section 2 of the pins is defined in the Sikorsky Service Bulletin) inspect the external surface of this tapered section using a magnifying glass (2 power minimum). If a crack is found replace the hinge pin prior to further flight.

(3) If a defect is found on the interior surface of the tapered part of the hinge pin (section 2 of the pin is defined in the Sikorsky Service Bulletin) and no crack is detected on the external surface of this section:

(i) Perform a daily visual inspection of the external surface of section 2 using a magnifying glass (2 power minimum). If a crack is found remove the hinge pin from service before further flight.

(ii) The hinge pin must be removed from service within the next 50 hours' time in service.

This amendment effective October 30, 1967.