The FAA has issued an airworthiness directive, effective Sept. 29, 2011, for a number of Lycoming reciprocating engines; the specific number of engines is two. The agency has decided that an unsafe condition exists that caused the failure of a crankshaft after 440 hours of operation. The cause of the failure was determined to be an improperly counterweighted crankshaft installed by a repair station. The FAA says it is issuing the AD because it has determined the unsafe condition is likely to exist “in other products of the same type design” … specifically Lycoming model IO-720-AIB engine serial numbers L-1457-54A and L-1458-54A, which it has been unable to locate.
According to the FAA, the condition of the wayward engines “warrants immediate notice to advise the current or subsequent owner of the need to inspect the engines before further flight.” But the FAA doesn’t know where the engines are, or if they’re in service. They were last known to be installed in a single Beech U-8F Queen Air registered as N51779, operating in the southern U.S. and Mexico. The aircraft’s last registered owner appears to be Joronamo Inc., listed in Wilmington, Del. According to FlightAware.com, the Queen Air was flown Jan. 31, 2011, between Arlington Municipal airport and Mid Valley airport, on Texas’ border with Mexico. The FAA estimates cost of compliance, which includes an engine inspection, to be about $170 dollars, as the required parts would cost nothing. Find the full AD online.
