AD 72-21-04

72-21-04 AVCO LYCOMING: Amdt. 39-1532. Applies to HIO-360-D1A model engines installed on Hughes Model 269C and 300C helicopters. Compliance required as indicated after effective date of this AD. To prevent possible failures of the Bendix S4LN-1208 magnetos, P/N 10-349285-5, accomplish the following: 1. Within the next 50 hours time in service and at each 50 hours time in service thereafter, inspect and lubricate the magneto distributor bushing of both magnetos in accordance with Lycoming Service Bulletin No. 336B or later revision or equivalent procedure approved by Chief, Engineering and Manufacturing Branch, FAA, Eastern Region. 2. Within the next 100 hours time in service and at each 100 hours time in service thereafter, replace those parts in the left magneto with the parts contained in Bendix Kit No. 10-391320 or equivalent FAA-approved parts. 3. Upon request, with substantiating data submitted through an FAA maintenance inspector, the compliance time may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. This amendment is effective October 13, 1972.