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.

Supersedes Service Letter No. L197

January 19, 1988

Models Affected

To all Owners and Operators of Textron Lycoming Piston Aircraft Engines

In order to minimize valve sticking problems, procedures recommended in this Service Letter should be followed. Depending on the degree of intensity, sticking between the valve stem and guide can severely restrict the valve's opening and closing movements. A sticking valve condition is often identified by an intermittent hesitation, or miss, in engine speed.

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

Supersedes Service Bulletin No. 505A

December 1, 1997

MODELS AFFECTED

The following Textron Lycoming four cylinder engines which utilize fixed pitch propellers except those installed in rotary wing aircraft or new engines shipped after February 15,1997:

All 320 series engines; and

All 180 horsepower, 360 series engines except the O-360-A4A, -A4D, A4G, - A4J, -A4K, -A4M, -A4N, -A4P -C4F, -C4P, IO-360-L2A and AEIO-360-B4A engine models.

TIME OF COMPLIANCE

Uncoated Crankshafts (no "PID" stamped on flange OD, see Figure 1)

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.

Supersedes Service Letter No. L185 A

January 19, 1988

Models Affected

To all Owners and Operators of Textron Lycoming Aircraft Engines