DATE: January 26, 2001 MODELS AFFECTED O-235 aircraft engines operated under the authority of the French Direction Generale De L’Aviation Civile (DGAC.) TIME OF COMPLIANCE At owner’s discretion. The French DGAC has reported a significant number of O-235 cylinder barrel failures in France. These failures have initiated from corrosion pits at the base area of the cylinder.

DATE: January 11, 2001 MODELS AFFECTED All O-540-F1B5 model engines installed in Robinson R-44 helicopters. TIME OF COMPLIANCE At overhaul. Textron Lycoming has revised the counterweight tuning to lessen vibration characteristics for the O-540- F1B5 model engine installed in those Robinson R-44 helicopter which use the new Robinson fanshaft P/N C007-5.

DATE: December 20, 2000 MODELS AFFECTED Textron Lycoming VO-435-B1A model engines. TIME OF COMPLIANCE At overhaul or whenever the accessory drive gear and shaft assembly P/N 76327 is disassembled. Any time the accessory drive gear and shaft assembly, P/N 76327, is disassembled, replace the three standard dowels, P/N 76323, connecting the gear and shaft with oversize dowels P/N 76323-P15.

Supersedes Service Instruction No. 1502 December 19, 2000 MODELS AFFECTED All Textron Lycoming IO-360-L2A aircraft engines. TIME OF COMPLIANCE Whenever the engine has vapor related problems, or at owner’s discretion. To reduce the possibility of vapor related problems in aircraft employing IO-360-L2A model engines, the flow divider should be modified into an inverted flow divider.

Supersedes Service Instruction No. 1304H November 12, 1999 MODELS AFFECTED All Textron Lycoming aircraft engines. TIME OF COMPLIANCE Whenever a nameplate is lost or an engine modification affects model designation. A replacement nameplate, to replace one that has been lost, will be issued only upon written request when accompanied by a document from the FAA authorizing a replacement nameplate.

Supersedes Service Instruction No. 1191 September 28, 1998 MODELS AFFECTED All Lycoming aircraft engines. TIME OF COMPLIANCE As required to determine cylinder compression The condition of the working parts in the combustion chamber of a cylinder can be determined by measuring the static leak rate of the cylinder as compared to the leak rate through an orifice of specified size. This is...

Supersedes Service Instruction No. 1187H DATE: May 23, 1997 MODELS AFFECTED TIO-540-A1A, -A1B, -A2A, -A2B, -A2C, -C1A, -F2BD, -J2B, -J2BD, -N2BD, -AA1AD, -AB1AD, -AF1A, -AF1B, -AG1A; LTIO-540-F2BD, -J2B, -J2BD, -N2BD. TIME OF COMPLIANCE On newly installed engines; before aircraft is flown. Also recommended at 100 hour inspection or at owner's discretion. Although engines are thoroughly tested...

Supersedes Service Instruction No. 1241B DATE: April 18, 1997 MODELS AFFECTED All Textron Lycoming engines. TIME OF COMPLIANCE Prior to initial start after engine change, overhaul, oil cooler replacement or draining or any prolonged period of inactivity. To avoid possible high speed bearing failure resulting from lack of lubrication during initial starts all aircraft engines should be pre-oiled...