Service Bulletin No. 656A
REPLACEMENT OF 6-CYLINDER ELECTRONIC IGNITION SYSTEM (EIS)
DATE:
April 2, 2025
MODELS AFFECTED:
All 6-cylinder EIS used in a helicopter application operating in any category
Service Letter No. L 162 B
Service Letter No. L162B
(Supersedes Service Letter No. L162A)
DATE RELEASED:
January 29, 1982
TO:
All Owners, Operators and Service Facilities
Service Bulletin No. 661
Service Bulletin No. 661
STD-35 Plain Washer Replacement
February 20, 2025
MODELS AFFECTED
All Lycoming Reciprocating Aircraft Engines
TIME OF COMPLIANCE
At overhaul or at the next maintenance event which requires removal of STD-35 plain washers, whichever occurs first.
Service Bulletin No. 659
Service Bulletin No. 659
STD-33 Plain Washer Replacement
February 20, 2025
MODELS AFFECTED
All Lycoming Reciprocating Aircraft Engines
TIME OF COMPLIANCE
At overhaul or at the next maintenance event which requires removal of STD-33 plain washers, whichever occurs first.
Service Bulletin No. 648 C
Service Bulletin No. 648C
Wastegate Solenoid Valve Inspection and Cleaning
February 20, 2025
MODELS AFFECTED
TEO-540-C1A
TIME OF COMPLIANCE
During each scheduled oil change
REASON FOR REVISION
Added new NOTICE and steps 6 and 7 to the procedure for Helicoil® inspection. Added sentence that S.B provides ICA.
IO-540-AG1A5 Series Engine Installation and Operation Manual
DATE RELEASEED:
November 2012
TITLE:
IO-540-AG1A5 Series Engine Installation and Operation Manual
DOCUMENT PART NUMBER:
60297-45
MODELS AFFECTED:
IO-540-AG1A5 Series
YO-233-B2A Series Engine Installation and Operation Manual
DATE RELEASEED:
December 2013
CURRENT REVISION:
November 2014
TITLE:
YO-233-B2A Series Engine Installation and Operation Manual
DOCUMENT PART NUMBER:
60297-40 & 60297-40-B
MODELS AFFECTED:
YO-233-B2A Series
IO-540-AF1A5 Operation and Installation Manual
DATE RELEASEED:
February 2008
TITLE:
IO-540-AF1A5 Operation and Installation Manual
DOCUMENT PART NUMBER:
60297-33
MODELS AFFECTED:
IO-540-AF1A5
TIO-540 Series Parallel Valve Cylinder Heads Operator’s Manual
DATE RELEASEED:
March 2006
CURRENT REVISION:
October 2006
TITLE:
TIO-540 Series Parallel Valve Cylinder Heads Operator’s Manual
DOCUMENT PART NUMBER:
60297-23P & 60297-23P-2
MODELS AFFECTED:
TIO-540 series
O-320 76 Series Operator’s Manual
DATE RELEASEED:
April 2007
CURRENT REVISION:
September 2008
TITLE:
O-320 76 Series Operator’s Manual
DOCUMENT PART NUMBER:
60297-22 & 60297-22-1
MODELS AFFECTED:
O-320