DATE: January 28, 2026 SUBJECT: Approved Spark Plugs MODELS AFFECTED: All Lycoming piston aircraft engines TIME OF COMPLIANCE: As required for replacement REASON FOR REVISION: Added Lubricating Spark Plug Ignition Leads section. Added an “A” to some engine models for Champion REM 40E in Tables 2 and 3. Added an “A” for several engine models for Tempest spark plugs in Tables 2, 4, and 5. Added an...

DATE: February 10, 2026 MODELS AFFECTED: All Lycoming reciprocating aircraft engines TIME OF COMPLIANCE: BEFORE FURTHER FLIGHT REASON FOR REVISION Added an item to the “A propeller strike includes:” section. Added a new NOTICE in the “Recommended Corrective Action for Propeller Strikes” section. Changed 17-grit to 150-grit in both checklists. In the checklist for All Engines - Except Geared...

DATE: February 10, 2026 MODELS AFFECTED: TEO-540-C1A TIME OF COMPLIANCE: At next maintenance event

DATE February 10, 2026 MODELS AFFECTED All Lycoming opposed series aircraft engines. TIME OF COMPLIANCE When preservation oil is removed or when lubricating oil is changed or added. REASON FOR UPDATE Updated lubrication oils and temperature ranges.

DATE February 10, 2026 MODELS AFFECTED 0-235 and 0-290 Series Engines TIME OF COMPLIANCE During engine overhaul or earlier REASON FOR REVISION Updated part number

DATE February 10, 2026 SUBJECT New Connecting Rod Bushing MODELS AFFECTED All Lycoming Engine Models TIME OF COMPLIANCE As Required REASON FOR REVISION Updated Figure 1 to show the notch and split in the connecting rod bushing. Revised the first paragraph. Deleted NOTICE that referenced previous part number. Referenced bushing split in Step F.