AD 2004-05-24 69 FR 12057

The FAA is superseding an existing airworthiness directive (AD) for Lycoming Engines (Formerly Textron Lycoming) AEIO-540, IO-540, LTIO-540, O-540, and TIO-540 series reciprocating engines. That action requires replacing certain zinc-plated crankshaft gear retaining bolts. This action retains that requirement, but expands the population of affected engines. In addition, this AD adds five additional kits for replacing the crankshaft gear retaining bolts. This AD results from notification from the Manufacturer of 161 engines not identified in the previous AD. This AD also results from approval of the five additional kits as alternative methods of compliance with AD 2002-23-06. We are issuing this AD to prevent loss of all engine power and possible forced landing.