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Airworthiness Directive

AD 2026-17-10 91 FR 55451

Federal Aviation Administration · 14 CFR part 39

FR document
2026-17584
Amendment
39-23454
Published
2026-08-28
Models covered
2
Last live check
2026-09-01

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AD

2026-17-10

FR doc 2026-17584 · 91 FR 55451

AD 2026-17-10Published 2026-08-28Effective 2026-09-14

Federally required — FAA rule. Every Airworthiness Directive is a legally enforceable FAA rule (14 CFR 39.3); operating a product that does not meet it is a violation (14 CFR 39.7).

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.

Full official abstract

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.

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Applies to 2 models in our index

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