The FAA has issued an emergency airworthiness directive calling for crankshaft replacement in Textron Lycoming TIO-540 and LTIO-540 turbocharged engines rated at 300 horsepower or more. This AD affects some 399 engines installed in Cessna T206; Piper Navajo, Mojave, Saratoga, Aerostar, and Malibu Mirage; and El Gavilian aircraft.
Owners must comply with the AD within 10 operating hours. The AD includes the serial numbers of the affected engines. The AD covers engines with crankshafts manufactured between March 1, 1999, and December 31, 1999.
At this point, the AD only applies to turbocharged engines. However, the FAA tells AOPA that it is continuing to investigate to determine if the AD should be applied to normally aspirated engines as well.
The AD was prompted by some 14 crankshaft failures. Of the seven engines that Lycoming was able to test, each failure was attributed to a materials problem for which there was no existing quality control protocol.
According to the previously issued Lycoming service bulletin, the company will reimburse owners for parts and labor. The engine must be returned to the factory for repair. See the SB for details.
Lycoming has told AOPA that they have enough replacement crankshafts to repair all affected engines. The company expects to be able to repair about 25 engines per week.