Service Instruction No. 1238 B

Supersedes Service Instruction No. 1238A

January 6, 2010

MODELS AFFECTED

Lycoming turbocharged engines.

TIME OF COMPLIANCE

When assembling V-band couplings to the engine.

V-band couplings are employed by Lycoming on certain airframe applications such as the Piper Malibu and Saratoga or by other airframe manufacturers at various locations in turbocharger exhaust systems. They are used primarily to seal joints in the exhaust system without the necessity for heavy bolted flanges. The typical V-band coupling joint consists of the coupling, two flanges and a metal gasket.