2026-17584RuleWallet

Lycoming Engines Face FAA Mandate for Piston Pins and Oil Inspections

Published Date: 8/28/2026

Rule

Summary

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.

Analyzed Economic Effects

4 provisions identified: 0 benefits, 3 costs, 1 mixed.

Immediate piston-pin replacement & inspections

If your airplane has a Lycoming engine with piston pin P/N LW-13445 (with an FAA Form 8130-3 dated between January 7, 2021 and December 15, 2025, or with no readable/available Form 8130-3), you must replace the affected piston pin with a part eligible for installation. You must also do an oil change and visually inspect the oil filter, oil pressure screen, and oil suction screen for metal particulates: within 5 hours time-in-service (TIS) after the AD takes effect unless an oil change was done within the last 10 hours TIS, or before further flight for engines listed in Table 3 with more than 150 hours TIS since installation. Replacement deadlines vary by engine model and serial number, including replacement within 25 hours TIS for some engines.

FAA estimated compliance cost per engine

The FAA estimates this AD affects 957 U.S.-registered engines and estimates cost per engine at $2,370 (2 work-hours at $85 per hour = $170 labor plus $2,200 parts), for a U.S. total of $2,268,090. The FAA notes some costs may be covered under warranty.

Ban on installing affected piston pins

After September 14, 2026, you may not install an affected piston pin as defined in the AD (P/N LW-13445 with an FAA Form 8130-3 dated January 7, 2021 to December 15, 2025, or with an unreadable/unavailable Form 8130-3) on any engine. A "part eligible for installation" must either not be P/N LW-13445 or must have a Form 8130-3 showing a production date outside the Jan 7, 2021–Dec 15, 2025 range.

Limits on special flight permits

Special flight permits under 14 CFR 21.197 and 21.199 may be issued to allow flights for the piston-pin replacement provided no metal particulates are found during the required inspection. However, special flight permits are not allowed to perform the visual inspection of the oil filter, oil pressure screen, and oil suction screen required by this AD.

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Key Dates

Published Date
Rule Effective
Comments Due
8/28/2026
9/14/2026
10/13/2026

Department and Agencies

Department
Independent Agency
Agency
Transportation Department
Federal Aviation Administration
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