66-19-04 SIKORSKY: Amdt. 39-269 Part 39 Federal Register August 4, 1966. Applies to Models S-58 and S-61 Series Helicopters Equipped With Tail Rotor Blades With Serial Numbers Listed in the Appendix of Sikorsky Service Bulletin 58B15-6A, Dated May 18, 1966, or 61B15-5A, Dated May 18, 1966, As Applicable.
Compliance required within the next 50 hours' time in service after the effective date of this AD unless already accomplished.
To prevent operation with tail rotor blades of less than minimum hardness in the flex shank area of the spar, accomplish the following:
(a) Inspect S 1615-30100, S 6115-30001, and S 6117-30001 Series tail rotor blades in the manner set forth in Sikorsky Service Bulletin 58B15-6A or 61B15-5A as applicable.
(b) Before further flight, remove from service blades that do not meet the minimum hardness requirements for the flex shank area of the spar specified in the applicable Service Bulletin.
This directive effective August 14, 1966.