AD 59-10-07

59-10-07 LYCOMING: Applies to O-320, O-340, O-360, GO-480, GSO-480, IGSO-480 and O-540 Series Engines As Noted.

Compliance required as soon as possible but not later than July 1, 1959.

It has been found that due to normal expansion of the cylinders during engine operation, the cylinder baffle clamps can become wedged between the cylinders causing barrel distortion and possible extensive damage to the cylinder bore and piston assembly. To correct this condition, the cylinder baffle clamps must either be

(1) removed and replaced with baffle retainers and retainer hooks, or

(2) removed and reworked to provide more clearance between the lower portion of the clamp and the cylinder.

Lycoming Service Bulletin No. 254A lists the parts required to comply with alternate method (1) above. An acceptable method of accomplishing the rework noted as alternate method (2) is also outlined in that bulletin, as well as the serial numbers of engines which comply with the requirements of this directive as delivered from the factory.