AOPA questions logic of possible Lycoming crankshaft AD

February 3, 2006

AOPA questions logic of possible Lycoming crankshaft AD

Lycoming engine

The other boot has dropped, and it's a size 15. Lycoming has issued a service bulletin calling for the "retirement" of some 5,000 crankshafts in engines ranging from the O-360 to the IO-720. And the FAA is considering an airworthiness directive (AD) that would make the service bulletin (SB) mandatory for Part 91 aircraft owners.

"Even Lycoming concedes that there have been no failures with these crankshafts," said Luis Gutierrez, AOPA director of regulatory and certification policy. "The FAA needs to do its homework and ensure that there is compelling, risk-based data to support what will be an expensive proposition for owners."

While customary procedure is for the FAA to solicit user input and experience before issuing an AD, the agency has not yet done that.

AOPA is "strongly urging" the FAA to go through the Airworthiness Concern Sheet (ACS) process. That process would allow the FAA to consult with owner groups and type clubs to obtain operational data on crankshaft problems and consider alternatives before unnecessarily hitting owners with a $35 million bill. The association is also arguing that if crankshaft replacement is warranted, it should be based on time in service, rather than an arbitrary calendar time.

"The FAA seems to be receptive to that," said Gutierrez, "and that would have a real cost of ownership benefit for most private aircraft owners."

That's because the Lycoming SB calls for the crankshaft to be replaced whenever the crankcase is opened, the engine overhauled, or within three years, which ever comes first. And unlike previous ADs where the company paid all expenses for replacing the crankshaft, Lycoming is only offering to provide a $2,000 "crankshaft kit." If the SB requirements are written into an AD, owners could be faced with a $6,000 to $7,000 bill within three years.

"In three years, some owners may still have less than 500 hours on their crankshafts," said Gutierrez. "That is why it is essential that any retirement scheme not be arbitrary but based on solid data that indicates when the failures are likely to occur."

AOPA will also be urging Lycoming to provide the same kind of benefits to owners as it has with the previous ADs.

March 2, 2006