October 17, 2008 MODELS AFFECTED All Lycoming new, overhauled, rebuilt, or repaired engines with: 1. A Slick model 4200/4300/6200/6300 series magneto with a serial number beginning with 0409#### through 08080453. 2. A LASAR model 4700/6700 series magneto with a serial number beginning with 0409#### through 08080453. 3. Any magneto which has had the carbon brush or distributor block assembly...

October 5, 2015 MODELS AFFECTED IO-320, -360, -390, -540, -580; AEIO-320, -360, -390, -540; LIO-320-B1A; O-320-B2D, -D1D; (L)O-360-A1H6, -A1N6, -A1G6D; HIO-360; LIO-360; O-360-A1H, -A2G, -A4G, -A4J, -A4K, -A1G6, -C1F, -C4F; O-540-L3C5D; and TO-360-C1A6D TIME OF COMPLIANCE 50 hours from the issue date of this Service Bulletin or the next regularly scheduled maintenance event (whichever occurs first...

August 16, 2016 MODELS AFFECTED All Lycoming engines with thermostatic oil cooler bypass valves: Part number (P/N) 53E19600 (with thermostatic oil cooler bypass valve serial numbers less than 53788), P/N 75944, P/N LW-13230, and P/N 53E19980 (with thermostatic oil cooler bypass valve serial numbers less than 159) TIME OF COMPLIANCE At the next oil change, not to exceed 50 hours, then annually...

June 17, 2016 MODELS AFFECTED All Lycoming engines equipped with Fuel Pump Part Number 62D26030, 62D26032, 62D26034, 62D26035, 62D26036, or 62D26037. TIME OF COMPLIANCE At the next regularly scheduled inspection or twelve (12) months after the effective date of this Service Bulletin (whichever occurs first.) This Service Bulletin is notification of required action for mandatory compliance with...

June 2, 2016 MODELS AFFECTED All Lycoming engines equipped with Marvel-Schebler, Facet, Precision, or Volare updraft carburetor models MA-3A, MA-3PA, MA-3SPA, MA-4SPA, MA-4-5, MA-4-5AA, and MA-6AA. TIME OF COMPLIANCE Within the next 50 hours of engine operation and every 50 hours thereafter during routine engine maintenance REASON FOR REVISION Correct the CAUTION after Step 3. Instances have been...

Date: September 9, 2016 SUBJECT Inspection and Removal of TCM and Bendix S-20 and S-1200 Series Impulse Coupling Magnetos. MODELS AFFECTED All Lycoming aircraft engines with TCM and Bendix S-20 and S-1200 series impulse coupling magnetos. TIME OF COMPLIANCE Within the next 10 hours of engine operation. REASON FOR REVISION Exclusion of Bendix Model S-20 or S-1200 magnetos with a snap-ring impulse...

Date: September 12, 2016 REASON FOR SUPPLEMENT Provide an alternate method of compliance to Service Bulletin No. 475C if the crankshaft gear is replaced rather than modified. NOTICE: Incomplete review of all the information in this document can cause errors. Read the entire Supplement to make sure you have a complete understanding of the requirements. The FAA has approved this supplement as an...

What is Detonation? Detonation is the abrupt combustion or explosion of the fuel charge inside the cylinder. During normal combustion, the spark plugs ignite the fuel charge and the fuel has a consistent and even burn as the piston moves through the power stroke and chemical energy is efficiently converted to mechanical. In simplified terms, when detonation occurs, the fuel charge ignites quickly...

DATE: October 18, 2016 MODELS AFFECTED: All Lycoming reciprocating aircraft engines TIME OF COMPLIANCE: BEFORE FURTHER FLIGHT REASON FOR REVISION Applies to all Lycoming aircraft engines (not just direct drive engines); added checklist specific for Lycoming geared engines; updated checklist which applies to all other Lycoming aircraft engines, added check for connecting rod squareness to the...