67-09-02 BRANTLY: Amdt. 39-373 Part 39 Federal Register March 21, 1967. Applies to Models B-2, B-2A, and B-2B Helicopters with P/N B2-324 Transmission Serial Numbers Prior to Serial Number 307.
Compliance required as indicated.
To improve the service life and reliability of the upper main rotor mast bearing, within the next 100 hours' time in service after the effective date of this AD, remove the Fafnir P/N 212K bearing presently installed and replace it with an Indiana Gear Works P/N 4524A56, Revision E, sealed bearing. This substitution is to be accomplished as prescribed by Brantly Helicopter Company Service Bulletin No. 21 and applicable sections of the Model B-2 Series helicopter maintenance manuals.
This directive effective April 20, 1967