Airworthiness Directives; Lycoming Engines
Key claim: The FAA is requiring owners of certain Lycoming O-235, O-540, and IO-540 engines to replace a defective piston pin that has been breaking and causing engine failures, and to inspect the oil system for metal debris.
Abstract
(Rule · Transportation Department, Federal Aviation Administration) The FAA is adopting a new airworthiness directive (AD) for certain Lycoming Engines (Lycoming) Model O-235, O-540, and IO-540 engines with a certain piston pin installed. This AD was prompted by several reports of piston pin failure that resulted in metal particulate contamination in the engine oil and engine failure. This AD requires replacement of the affected piston pin with a part eligible for installation and, for certain engines, oil change and visual inspection of the engine oil filter, oil pressure screen, and oil suction screen for metal particulates. This AD also prohibits the installation of an affected piston pin on any engine. The FAA is issuing this AD to address the unsafe condition on these products.
Why this matters
Piston pin failures in Lycoming engines have caused in-flight engine failures on general aviation aircraft, making this a direct flight-safety issue for owners of affected O-235, O-540, and IO-540 powered airplanes. The AD is a routine but consequential compliance action requiring both parts replacement and oil-system contamination inspection before further flight.