60-23-05 VERTOL: Amdt. 218 Part 507 Federal Register November 8, 1960. Applies to All 42 and 44 Series Helicopters.
Compliance required as indicated.
As a result of a recent fatigue failure of the lower directional bellcrank assembly, P/N 22C1611-13, all Vertol parts P/N 22C1611-13 must be retired upon the accumulation of 2,500 hours of time in service.
This directive effective November 8, 1960.