May 12, 2025
TEO-540-C1A
N/A
This Service Instruction is in response to incorrectly marked alternator belts having reached the field on engines or as spare parts.
April 2, 2025
All 6-cylinder EIS used in a helicopter application operating in any category
Service Letter No. L162B
(Supersedes Service Letter No. L162A)
January 29, 1982
All Owners, Operators and Service Facilities
Service Bulletin No. 661
STD-35 Plain Washer Replacement
February 20, 2025
All Lycoming Reciprocating Aircraft Engines
At overhaul or at the next maintenance event which requires removal of STD-35 plain washers, whichever occurs first.
Service Bulletin No. 659
STD-33 Plain Washer Replacement
February 20, 2025
All Lycoming Reciprocating Aircraft Engines
At overhaul or at the next maintenance event which requires removal of STD-33 plain washers, whichever occurs first.
Service Bulletin No. 648C
Wastegate Solenoid Valve Inspection and Cleaning
February 20, 2025
TEO-540-C1A
During each scheduled oil change
Added new NOTICE and steps 6 and 7 to the procedure for Helicoil® inspection. Added sentence that S.B provides ICA.
November 2012
IO-540-AG1A5 Series Engine Installation and Operation Manual
60297-45
IO-540-AG1A5 Series
December 2013
November 2014
YO-233-B2A Series Engine Installation and Operation Manual
60297-40 & 60297-40-B
YO-233-B2A Series
February 2008
IO-540-AF1A5 Operation and Installation Manual
60297-33
IO-540-AF1A5
March 2006
October 2006
TIO-540 Series Parallel Valve Cylinder Heads Operator’s Manual
60297-23P & 60297-23P-2
TIO-540 series
