Service Bulletin No. 552
Crankshaft Replacement in Lycoming TIO and LTIO-540 Engines Rated at 300 Horsepower and Higher
Supersedes and Replaces Service Bulletin No. 550
DATE: August 16, 2002
Service Bulletin No. 552 applies only to TIO and LTIO-540 engines rated at 300 horsepower or higher.
Engines that previously complied with Service Bulletin No. 550 are also affected by Service Bulletin No. 552.
TIME OF COMPLIANCE
Before further flight.
Lycoming has received several field reports of broken crankshafts in six-cylinder turbocharged engines rated at 300 horsepower or higher. The problem is related to the material used in these crankshafts. Due to the nature of the problem, there is no field process currently available to identify crankshafts potentially affected. The engines assembled with the suspect crankshaft are listed in Table 1 below. Affected crankshaft serial numbers are listed in Table 2.
Supplement No. 1 to Service Bulletin No. 552
For more information on Crankshaft Replacement, refer to Supplement No. 1 to Service Bulletin No. 552.