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60-11-06 LYCOMING: Amdt. 162 Part 507 Federal Register May 27, 1960. Applies to GO-480-C, -G and All GSO-480 Series Engines.
Compliance required at first engine overhaul after July 1, 1960.
To prevent excessive crankshaft counterweight bushing wear and subsequent detuning of the counterweights, crankshafts with cast counterweights must be modified to incorporate forged counterweights with hardened steel counterweight bushings.
(Lycoming Service Bulletin No. 249A covers this same subject.)
Federal Register Information