Lycoming Piston Pin AD Revised and Expanded

The FAA has issued AD 2026-22-13, which supersedes AD 2026-17-10 and extends the piston pin requirements to more Lycoming engines. Since the original AD was issued in August, Lycoming has identified additional engine models with the same unsafe condition, and the FAA has clarified which pins are affected. The AD now covers certain O-235, O-320, IO-320, AIO-320, LIO-320, AEIO-320, VO-435, TVO-435, O-540, and IO-540 engines with piston pin P/N LW-13445 manufactured between January 7, 2021, and December 15, 2025, or with an unknown manufacture date. The AD was prompted by reports of metal particulates in engine oil and two engine failures that gave no warning beforehand. The FAA estimates 957 U.S.-registered engines are affected, at about $4,325 per engine, although Lycoming says some costs may be covered under warranty.

The compliance requirements depend on when the pin was made. For pins made between January 7, 2021, and March 22, 2023, operators must change the oil and inspect the oil filter and the oil pressure and suction screens for metal within 5 hours time-in-service (TIS). If no metal is found, the pins can be replaced at the next cylinder removal or overhaul. For pins made between March 23, 2023, and December 15, 2025, or with an unknown date, engines with 150 or more hours TIS must have the pins replaced before further flight. Engines with fewer than 150 hours must complete the oil inspection within 5 hours, then replace the pins within 25 hours TIS or before reaching 150 hours since the pins were installed, whichever comes first. If metal is found, the pins must be replaced before further flight. Special flight permits are allowed for the pin replacement if no metal is found, but not for the oil inspection. The AD is effective November 24, 2026, and comments are due December 24, 2026. You can view the AD here.