In what some may see as “déjà vu all over again,” Lycoming has issued a mandatory service bulletin recalling what appears to be 1,227 crankshafts, some installed, some shipped as spares.
Engines that have complied with Service Bulletins 552 or 553 are not affected. The affected engines are O-540, IO-540, AEIO-540 and TIO-540s rated at 290 hp or less and listed in the first of four tables issued with the service bulletin. Affected IO-540-P, -S and –AA engines of 250 to 290 hp are listed in Table 2, as are IO-540 and AEIO-540 engines of 300 hp. A third table lists counterweighted (L)O-360, (L)IO-360 and AEIO-360 engines of any horsepower.
In all cases, the affected engines must have been “manufactured, rebuilt, overhauled or repaired after March 1, 1999,” according to the bulletin.
Compliance is necessary within the next 50 operating hours or six months from July 11 (the bulletin’s issue date), whichever comes first.