DATE RELEASED: April 17, 2017 The FAA has approved this supplement as an Approved Alternate Method of Compliance (AMOC) to AD 2015-19-07.

DATE RELEASED: April 5, 2017 TO: All Owners and Operators of Lycoming Direct Drive Engines REASON FOR SERVICE LETTER: This Service Letter identifies extended maintenance intervals as benefits of routine exclusive use of approved unleaded fuels identified in the latest revision of Service Instruction No. SI-1070 for Lycoming engine models.

DATE: May 4, 2017 MODELS AFFECTED: Lycoming engines using a thermostatic oil cooler bypass valve TIME OF COMPLIANCE: At overhaul or when necessary to replace the thermostatic oil cooler bypass valve REASON FOR REVISION: Clarify replacement valve part numbers for specific Lycoming engine models

May 25, 2017 MODELS AFFECTED: All Lycoming engine models including electronically-controlled engines TIME OF COMPLIANCE: Anytime aircraft is struck by lightning

May 25, 2017 MODELS AFFECTED: All Lycoming direct drive and TIGO-541 piston engines TIME OF COMPLIANCE: As per the schedule in Table 1

DATE RELEASED: November 1, 2009 TITLE: YIO-390-B Parts Catalog DOCUMENT PART NUMBER: PC-409-2

DATE RELEASED: March 1, 2016 TITLE: YO-233-B2A Parts Catalog DOCUMENT PART NUMBER: PC-YO-233-B2A

DATE RELEASED: November 1, 2009 TITLE: YIO-390-B Operations & Installation Manual DOCUMENT PART NUMBER: 60297-37