AD 67-17-06

67-17-06 SIKORSKY: Amdt. 39-415 Part 39 Federal Register May 16, 1967. Applies to Model S-55 Series Helicopters Equipped with S14-20-5300 Series Tail Cone and Pylon Assembly (Straight Tail Cone).

Compliance required as indicated.

To prevent operation with fatigue cracks in the pylon lower ring accomplish the following:

(a) Within the next 10 hours' time in service and thereafter at intervals not to exceed 10 hours' time in service from the last inspection, remove the pylon lower access cover and visually inspect for cracks pylon lower ring, P/N S14-20-3013, with 3,500 or more hours' time in service on the effective date of this AD.

NOTE: - Where excess paint that may hinder the visual inspection is present, remove with MIL-R-8633 water-soluble paint remover and apply a light coat of MIL-P-8585 zinc chromate primer.

(b) If a crack is found, replace the pylon lower ring assembly, P/N S14-20-3052, before further flight.

(c) Remove from service pylonlower ring assembly, P/N S-14-20-3052, with 3,400 or more hours' time in service on the effective date of this AD within the next 100 hours' time in service.

(d) Remove from service all other pylon lower ring assemblies, P/N S14-20-3052, before the accumulation of 3,500 hours' time in service.

(e) Operators who have not kept records of hours of time in service on pylon lower ring assembly, P/N S14-20-3052, shall substitute helicopter hours of time in service in lieu thereof.

(Sikorsky Service Bulletin 55B20-1E covers this subject.)

This directive effective May 21, 1967.