The Smart Marty Sky Dispatch
FAA Expands Lycoming Piston Pin AD
Lycoming piston pin defect prompts an expanded AD and could cost over $4000 per affected engine.
As we previously reported, the FAA issued an Airworthiness Directive (AD 2026-17-10) that applied to Lycoming Model O-235, O-540, and IO-540 engines with certain piston pins installed. The fix is replacing the pins with eligible replacements and for certain engines, metal inspection through oil and filter changes. But since the issuance of the AD back in October 2026, the FAA has identified more engines that are affected and also saw the need to make some clarifications above and beyond what is stated in Lycoming’s MSB 667A.
The current AD was prompted by reports from Lycoming of metal particulates found in the engine oil during oil change and two non-detectable engine failures.
To clarify, the AD requires oil change and visual inspection of the engine oil filter, oil pressure screen, and oil suction screen for metal particulates within five hours time-in-service. Additionally, affected engines will need to be inspected and have affected piston pins replaced within 25 hours time-in-service or earlier depending on the Lycoming engine model.
At first blush, it’s a bit muddy. The AD applies to engines with an installed piston pin with part number LW-13445 and that was manufactured between Jan. 7, 2021 to Dec. 15, 2025. If the date of manufacture for the piston pin cannot be determined, this AD is applicable. If the current LW-12445 piston pins were installed prior to Jan. 7, 2021, this AD doesn’t apply. The chart to the right is current list of affected engines.
For engines that are affected (the FAA estimates that 957 engines in the U.S. registry are), the AD says that ferry flights may be accomplished provided no metal particulates are found during the inspection required by the AD.
Labor costs for oil change and piston pin replacement is estimated at 25 shop hours, and at $85 per hour, that’s $2,125. Add the parts at $2,200 and the cost per product is $4,325. Lycoming said some of the costs to apply with AD might be covered under warranty.
The post FAA Expands Lycoming Piston Pin AD appeared first on AvBrief.com.