60-10-02 BRANTLY: Amdt. 151 Part 507 Federal Register May 12, 1960. The AD published in the Federal Register as Amendment 143 was superseded by the following: Applies to All B-2 Helicopters With 248-40 and 248-46 Main Rotor Blades Installed.
Compliance required as indicated.
The retirement time on 248-40 and 248-46 blades is increased from 50 hours of time in service specified in Amendment 143 of Part 507, to 500 hours of time in service, provided the following inspection is performed prior to flight subsequent to each refueling:
(a) (1) Visually inspect upper and lower skin for cracks in the vicinity of rivet heads on the inboard one-third of the outboard main rotor blades.
(2) Blades found with more than one crack or with a single crack exceeding one inch in length must be replaced prior to further flight.
(3) Blades found with a single crack of one inch or less in length must be stop-drilled with a 1/8 (0.125) inch diameter drill prior to further flight.
Revised March 10, 1961.