Warranty Repair of AVStar Fuel Systems, Inc. Fuel Control Products Date: April 16, 2018 TO: All Owners and Operators of Lycoming Piston Aircraft Engines SUBJECT: Warranty Repair of AVStar Fuel Systems, Inc. Fuel Control Products REASON FOR REVISION: Update AVStar warranty information sheet, and contact information.

DATE RELEASED: October 2017 TITLE: HIO-390-A1A Maintenance Manual DOCUMENT PART NUMBER: MM-HIO-390-A1A

DATE RELEASED: May 2018 TITLE: HIO-390-A1A Illustrated Parts Catalog DOCUMENT PART NUMBER: PC-HIO-390-A1A

DATE RELEASED: October 2017 TITLE: HIO-390-A1A Installation & Operations Manual DOCUMENT PART NUMBER: IOM-HIO-A1A

EXHAUST SYSTEM INSPECTION DATE: May 17, 2018 SUBJECT: Exhaust System Inspection MODELS AFFECTED: Lycoming Engine Model TIO-540-AJ1A TIME OF COMPLIANCE: If the Exhaust System is not replaced per this revision, after the initial Exhaust System Inspection, continue with subsequent repetitive Exhaust System Inspections per Table 2 in this Service Bulletin REASON FOR REVISION: Refined language on Page...

Warranty Procedure for Exhaust System Replacement Referenced in the most current revision of SB 627 DATE: May 17, 2018 TO: All Owners and Operators of Lycoming Engines Model TIO-540-AJ1A SUBJECT: Warranty Procedure for Exhaust System Replacement Referenced in the most current revision of SB627 REASON FOR REVISION: Updated language to refer to the most current revision of SB627

Plug Replacement of Vapor Return Fitting on Piper installation of IO-360- B4A DATE: August 3, 2018 SUBJECT: Plug Replacement of Vapor Return Fitting on Piper installation of IO-360- B4A MODELS AFFECTED: IO-360-B4A

Alternate Oil Sump Fitting Configuration for Aerobatic Inverted Oil System DATE: August 3, 2018 SUBJECT: Alternate Oil Sump Fitting Configuration for Aerobatic Inverted Oil System MODELS AFFECTED: IO-540-K1K5 Engines Installed in ENAER T-35 Pillan Aircraft TIME OF COMPLIANCE: As required by the aircraft manufacturer, based on parts availability* REASON FOR REVISION: Added additional section...

MAINTENANCE PROCEDURES AND SERVICE LIMITATIONS FOR VALVES DATE: February 18, 1977 MODELS AFFECTED: All Avco Lycoming opposed series aircraft engines. TIME OF COMPLIANCE: During periodic maintenance and when intake and exhaust valves are removed from cylinders.