Service Bulletin No. 637 Reprint of Slick/Champion Aerospace Service Bulletin SB1-19 March 14, 2019 MODELS AFFECTED All 4 and 6-cylinder Lycoming engines equipped with Slick 4300 or 6300 Series Impulse Coupled Magnetos. TIME OF COMPLIANCE Next maintenance event, or 400 hours total time in service of the magneto (whichever occurs first), then every 500 hours after the initial inspection. This...

NEW TURBOCHARGER MOUNTING HARDWARE DATE March 21, 2019 MODELS AFFECTED TO-360-C and -F series engines TIME OF COMPLIANCE At owner’s discretion or when part replacement is necessary. REASON FOR REVISION Revision A is being released to update the P/N of the strut assembly and various hardware P/N’s along with reformatting of the service instruction.

Oil Sump Baffle Replacement Supersedes Service Instruction No. 1279C May 15, 2019 MODELS AFFECTED: IO-540-AA1A5, -AA1B5, -AE1A5, -E1A5, -E1B5, -K1A5, -K1B5, -K1D5, -K1E5, -K1F5, -K1G5, -K1H5, -K1J5, -K1K5, -K1A5D, -K1G5D, -K1J5D, -L1C5, -M1A5, -M1C5, -M1B5D, -S1A5 TIO-540-A2B, -A2C, -AE2A, -AH1A, -F2BD, -J2B, -J2BD, -S1AD, -U2A LTIO-540-F2BD, -J2B, -J2BD, -U2A IO-580-B1A TIME OF COMPLIANCE...

SUBJECT: LYCOMING ENGINES' PRODUCT SUPPORT HOURS DATE RELEASED: JULY 12, 2019 TO: Owners and Operators of Lycoming Aircraft Engines

SERVICE LETTER NO. 277 HARTZELL ENGINE TECHNOLOGIES AND LYCOMING ENGINES ALTERNATOR DISTRIBUTION AGREEMENT DATE RELEASED: December 17, 2019 TO: Owners and Operators of Lycoming Aircraft Engines

Service Bulletin No. 639 Inspection of Rocker Arm, Part Number LW-15014 January 17, 2020 MODELS AFFECTED O-320-H2AD, O, LO, TO, LTO-360-E1A6D new, rebuilt, or overhauled engines shipped from Lycoming since June 2017 with less than 500 hours of operation or engines with less than 500 hours of operation since rocker arm replacement. TIME OF COMPLIANCE At next scheduled oil change, then every 50...

SPECIFIED FUELS FOR SPARK-IGNITED GASOLINE AIRCRAFT ENGINE MODELS DATE: April 8, 2020 SUBJECT: Specified Fuels for Spark-Ignited Gasoline Aircraft Engine Models MODELS AFFECTED: Lycoming engine models as detailed in Table 3 TIME OF COMPLIANCE: When refueling aircraft REASON FOR REVISION: Added listings for IO-390-D to Table 3

ENGINE INSPECTION AFTER OVERSPEED DATE: April 9, 2020 SUBJECT: Engine Inspection after Overspeed MODELS AFFECTED: All Lycoming piston engines. TIME OF COMPLIANCE: As required by the subject bulletin. REASON FOR REVISION: Added new engine model IO-390-D to Table 1. Added new steps in Table 4 to include EIS Overspeed. Added a new NOTICE before the Magneto Overspeed Inspection section. Added a new...

DATE RELEASED: June 2024 TITLE: IO-390-D Series Maintenance Manual (Principal Manual) (Rev 1) DOCUMENT PART NUMBER: Part No. MM-IO-390-D Series MM-IO-390-D Series IO-390-D Series Maintenance Manual – Revision 1 Update changes requested since original release. Changes made in following chapters: Airworthiness Limitations Sections 05-00 12-30 72-30 74-30