DATE RELEASED: March 2020 TITLE: IO-390-D Engine Installation and Operation Manual DOCUMENT PART NUMBER: Part No. IOM-IO-390-D Series

SUBJECT Propeller Flange Bushing Locations DATE April 9, 2020 MODELS AFFECTED All Certified Lycoming direct drive engines TIME OF COMPLIANCE At owner's discretion REASON FOR REVISION Added IO-390-D1A6, -D1B6, -D3A6, -D3B6 engine models to Table 1

COUNTERWEIGHTS AND ROLLERS ON ENGINE MODELS DATE: April 9, 2020 SUBJECT: Counterweights and Rollers on Engine Models MODELS AFFECTED: All Lycoming engines with counterweights TIME OF COMPLIANCE: As required REASON FOR REVISION: Added new engine models, IO-390-D Series to Table 5.

SERVICE TABLE OF LIMITS AND TORQUE VALUE RECOMMENDATIONS DATE RELEASED: April 13, 2020 TITLE: Service Table of Limits and Torque Value Recommendations DOCUMENT PART NUMBER: SSP-1776-5

SI-1060U – PUSH ROD IDENTIFICATION DATE: April 22, 2020 SUBJECT: Push Rod Identification MODELS AFFECTED: All Lycoming aircraft engines. TIME OF COMPLIANCE: Anytime push rod replacement is necessary. REASON FOR REVISION: Added IO-390-D to Tables 2 and 4. Revised CAUTION and NOTICE on page 1.

SERVICE INSTRUCTION NO. 1009 BE Time Between Overhaul (TBO) Schedules DATE: April 24, 2020 SUBJECT: Time Between Overhaul (TBO) Schedules MODELS AFFECTED: Lycoming Engine Models Defined Herein REASON FOR REVISION: Added a new paragraph at the end of the Operating Hour Time Period TBO section. Added new engine model IO-390-D to Table 1. Revised Table 2 to include separate listings for engine model...

SUBJECT: Repair of Oil Cooler By-Pass Valve Seat DATE: April 26, 1986 MODELS AFFECTED: PART I: All Avco Lycoming piston engines equipped with a P/N 75944 oil cooler bypass valve. PART II: All Avco Lycoming direct drive engines that incorporate either a dual magneto drive accessory housing or a P/N 69510 oil pressure screen and temperature valve housing on an individual magneto drive accessory...

Service Instruction No. 1579 Exhaust System Replacement Components DATE: November 20, 2020 SUBJECT: Exhaust System Replacement Components MODELS AFFECTED: TIO-540-AJ1A TIME OF COMPLIANCE: As required.

SERVICE LETTER NO. L282 Australian Fuel Testing DATE: December 11, 2020 TO: Australian Robinson R22 and R44 Owners and Operators REASON FOR PUBLICATION: This Service Letter transmits information pertaining to recent engine testing performed on Avgas grades used in Australia and the United States.