| 2026-17-10 | Reciprocating Engine Cylinder Section | Sep 14, 2026 | Engine (IO-540-C4B5)Serial numbers per Table 2 or Table 3 of Lycoming Mandatory Service Bulletin No. 667A, dated March 12, 2026. Only with: Installed piston pin P/N LW-13445 with an OEM FAA Form 8130-3 production dated between January 7, 2021 and December 15, 2025, or where the production date cannot be determined or the form is unavailable. |
| 2006-10-21 | Engine Components Incorporated (ECi) Reciprocating Engine Connecting Rods | Jun 22, 2006 | Engine (IO-540-C4B5)Only with: ECi connecting rods P/N AEL11750 (forging P/N AEL11488) installed, rod serial numbers 54/6 and below, produced between January 2002 and January 2004. |
| 2005-19-11 | Lycoming Engines (Formerly Textron Lycoming) AEIO-360, IO-360, O-360, LIO-360, LO-360… | Oct 21, 2005 | Engine (IO-540-C4B5)Only with: Engines rated at 300 HP or lower, manufactured new, rebuilt, or overhauled after March 1, 1999, or that had a crankshaft installed after March 1, 1999. |
| 2004-05-24 | Lycoming Engines (Formerly Textron Lycoming) AEIO-540, IO-540, LTIO-540, O-540, and… | Mar 30, 2004 | Engine (IO-540-C4B5)Only with: Engines with crankshaft gear retaining bolts P/N STD-2209 installed; excludes O-540-F series engines subject to AD 99-03-05 with bolt not since replaced, engines with bolt installed at original assembly or replaced by Lycoming per SB 554 after November 10, 1998, engines with bolt from replacement kits 05K19987, 05K23325, 05K23326, 05K23327, 05K23335 or 05K23336, and engines with single-drive dual magnetos. |