[Docket No. FAA-2005-21331; Directorate Identifier 2005-NE-07-AD; Amendment 39-14605; AD 2006-10-21]

ANN is looking over yet another Lycoming AD that was just published to the Federal Register, affecting a number of Lycoming 360 and 540 series engines, using ECi connecting rods.

According to the FAA, it is "adopting a new airworthiness directive (AD) for certain Lycoming Engines (formerly Textron Lycoming) 360 and 540 series reciprocating engines with ECi connecting rods, part number (P/N) AEL11750, installed. The Airmotive Engineering Corp, Division of Engine Components Incorporated (ECi), holds the Parts Manufacturer Approval (PMA) for the affected parts, and markets the parts as ECi parts."

"This AD requires replacing certain lot and serial numbered connecting rods, P/N AEL11750, having forging part number AEL11488. This AD would also prohibit installing certain ECi connecting rods, P/N AEL11750, into any Lycoming 360 or 540 series reciprocating engines. This AD results from reports of connecting rods with excessive variation in circularity of the journal bores. We are issuing this AD to prevent fatigue failure of the connecting rod and a possible uncommanded shutdown of the engine."

The AD becomes effective June 22, 2006.

In its final ruling, the FAA also addresses the comments made by many pilots that such an airworthiness directive is not needed, based on the relatively few incidents reported.

"Several commenters question the need for the connecting rod AD," the FAA stated. "We disagree. We confirmed that a manufacturing defect existed in the ECi connecting rods. The FAA has determined that this defect was the most probable cause of an engine shutdown and forced landing incident."

"ECi identified the manufacturing process deficiencies that were responsible for the defective condition and took specific actions to correct these deficiencies. We also determined that the subject ECi connecting rods in service could possess these manufacturing defects and could, therefore, fail during operation."

FMI: http://dms.dot.gov, AD 2006-10-21