Service Instruction No. 1409 C

Supersedes Service Instruction No. 1409B

February 20, 2009

MODELS AFFECTED

All Lycoming piston aircraft engines except for installations that utilize a friction type clutch and a common engine oil system for the transmission and clutch assembly. Check with airframe manufacturer prior to use in these installations.

TIME OF COMPLIANCE

At initial oil fill and every oil change thereafter.

Lycoming Engines has approved an oil additive, P/N LW-16702, that has an anti-scuffing agent. This characteristic serves to reduce wear. For engines already in service, the use of the additive may be started at the next oil change.