The FAA is asking for comments on an airworthiness directive (AD) for certain Lycoming engines. The AD, 2017-NE-27-AD, which requires an inspection of connecting rods and replacement of affected connecting rod small end bushings, was prompted by reports of connecting rod failures resulting in uncontained engine failure and in-flight shutdowns.
While the emergency AD became effective August 15, the FAA still wants to hear from the general aviation community.
According to the FAA, it has received five reports of uncontained engine failures due to failed connecting rods on various models of Lycoming engines. The agency warns that “this condition, if not corrected, could result in uncontained engine failure, total engine power loss, IFSD, and possible loss of the airplane. We are issuing this AD to prevent connecting rod failure.”
The FAA says 778 airplanes on the U.S. registry will be impacted by the AD, which carries an estimated total cost to U.S. engine owners of $1.1 million, or about $1,425 per engine, if no replacements are required.
If connecting rod or bushing replacement is required, the expected costs range from $2,170 for four-cylinder Lycoming engines to $6,680 for six-cylinder engines. The FAA notes that some of these costs may be covered under warranty.
The FAA said five uncontained engine failures in Lycoming engines have been reported, creating an unsafe condition that warrants the quick adoption of the AD. The agency anticipates making the AD final within 30 days. Lycoming has adopted a 10-hour in-service time of compliance for the service bulletin inspections.
Comments must be received by September 25.
