Subject: Lycoming Piston Engines
AD Number: AD/LYC/112 Lycoming Crankshaft Replacement 12/2005 DM
Applicability: Lycoming Engines AEIO-360, IO-360, O-360, LIO-360, LO-360, AEIO-540, IO-540, O-540, and TIO-540 series reciprocating engines, rated at 300 horsepower (HP) or lower, that are manufactured new, rebuilt, overhauled after 01 March 1999; OR that had a crankshaft installed after 01 March 1999.
Requirement: 1. AEIO-540, IO-540, O-540, and TIO-540 series engines manufactured new or rebuilt, overhauled, or that had a crankshaft installed after 01 March 1999: For AEIO-540, IO-540, O-540, and TIO-540 series engines manufactured new or rebuilt, overhauled, or that had a crankshaft installed after 01 March 1999, do the following:
a. If Table 1 or Table 2 of Lycoming Mandatory Service Bulletin (MSB) No. 566 dated 11 July 2005 lists your engine serial number (SN), use Table 4 to verify the crankshaft SN.
b. If Table 4 of Lycoming MSB 566 lists your crankshaft SN, replace the crankshaft with a crankshaft that is not listed in Table 4 of Lycoming MSB No. 566.
2. AEIO-360, IO-360, O-360, LIO-360, and LO-360 series engines manufactured new or rebuilt, overhauled, or that had a crankshaft installed after 01 March 1999:
For AEIO-360, IO-360, O-360, LIO-360, and LO-360 series engines manufactured new or rebuilt, overhauled, or that had a crankshaft installed after 01 March 1999, do the following:
a. If Table 3 of Lycoming MSB 566 lists your engine SN, use Table 4 to verify the crankshaft SN.
b. If Table 4 of Lycoming MSB 566 lists your crankshaft SN, replace the crankshaft with a crankshaft that is not listed in Table 4 of Lycoming MSB 566.
3. Do not install any crankshaft that has a SN listed in Table 4 of Lycoming MSB 566 into any engine.
Note: FAA Airworthiness Directive (AD) 2005-19-11 Amendment 39-14276 refers.
Compliance: 1. Unless accomplished earlier, within 50 hours time-in-service or 6 months after the effective date of this AD, whichever occurs first.
2. Unless accomplished earlier, within 50 hours time-in-service or 6 months after the effective date of this AD, whichever occurs first.
3. After the effective date of this AD.

This Airworthiness Directive becomes effective on 28 October 2005.

Background: There have been various crankshaft failures in Lycoming model 360 and 540 series engines rated at 300 HP or lower. Failure of crankshaft may result in total engine power loss, in-flight engine failure, and possible loss of the airplane. The actions specified by this Airworthiness Directive address the risk identified above.

FMI: www.casa.gov.au