AOPA sources within FAA Aircraft Certification recently notified the association of an impending expansion to a recently issued Lycoming crankshaft airworthiness directive (AD). The agency will publish a superseding AD early next week that may increase the applicability of an existing AD on turbocharged Lycoming TIO-540 engines, adding as many as 600 more engines.
The new AD will affect all aircraft equipped with a Lycoming TIO-540 (turbocharged at the factory or by STC) rated at 300 horsepower or more with crankshafts installed between March 1997 and the present. That includes Piper Mojave, Navajo, Malibu Mirage, and Saratoga, Aerostar, and the turbocharged Cessna Stationair. Crankshafts affected by the current AD, 2002-17-53, must still be replaced prior to further flight. Crankshafts affected by the impending expansion of the AD will be subject to metallurgical inspection within a prescribed time-in-service (TIS) interval, depending upon date of manufacture. Crankshafts deemed free of the suspected metallurgical deficiency will be cleared for immediate return to service, while defective cranks will be required to be replaced prior to further flight.
Lycoming representatives will reportedly conduct the AD-required crankshaft metallurgical inspections (a small "core sample" taken from the propeller flange for examination) at locations throughout the country. Information is not yet available regarding the time necessary for Lycoming to conduct the inspections. FAA sources indicate it will be at least two months before Lycoming is prepared to begin production of replacement crankshafts. Affected owners are advised to contact Lycoming at 570/323-6181. A copy of the new AD and details regarding AD applicability and compliance will be posted on AOPA Online as soon as it's published.