77-04-06 MESSERSCHMITT-BOLKOW-BLOHM (MBB): Amendment 39-2835 as amended by amendment 39-3528. Applies to all Model BO-105A and BO-105C helicopters, certificated in all categories.
Compliance is required as indicated.
To prevent the possible failure of a main rotor gearbox support, P/Ns 105-10161 and 105-10162, replace the two supports with serviceable supports within the next 10 hours time in service after the effective date of this AD or prior to the accumulation of 6,800 hours time in service on the supports, whichever occurs later, and, thereafter, continue to replace the supports prior to the accumulation of 6,800 hours time in service.
Amendment 39-2835 became effective March 3, 1977.
This amendment 39-3528 becomes effective August 23, 1979.