EASA AD US-2026-17-10
Reciprocating Engine - Piston Pin - Replacement
Summary
The Federal Register document titled "Reciprocating Engine - Piston Pin - Replacement" is a final rule airworthiness directive issued by the FAA affecting certain Lycoming Engines Model O-235, O-540, and IO-540. It addresses piston pin failures that have caused metal contamination in engine oil and engine failures. The directive mandates replacement of affected piston pins and inspections to prevent unsafe conditions.
What Changed
This new airworthiness directive introduces mandatory replacement of specific piston pins identified as defective due to microcracks and inclusions. It requires oil changes and visual inspections of engine oil filters and screens for metal particulates within 5 hours time-in-service for certain engines. It also prohibits installation of the affected piston pins on any engine.
Why It Matters
This directive is critical for aviation professionals because piston pin failure can lead to engine damage, oil starvation, in-flight shutdown, and loss of aircraft control. Operators and maintenance teams must comply promptly to ensure continued airworthiness and safety. The directive helps prevent costly engine failures and potential accidents by addressing a known manufacturing defect.
What To Do
Affected operators must replace the defective piston pins with eligible parts and perform oil changes and inspections of oil filters and screens for metal debris within 5 hours time-in-service unless recently done. Installation of affected piston pins is prohibited. Compliance must be completed by September 14, 2026, the effective date of the directive.
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