Service Letter No. 296
June 13, 2025
Service Letter No. L296
Announces obsoleted EIS parts kits
Service Bulletin No. 630B
Service Bulletin No. 630B
(Supersedes Service Bulletin No. 630A)
June 11, 2025
MODELS AFFECTED:
All Lycoming engines
TIME OF COMPLIANCE:
At every maintenance event that requires removal of each cylinder
Service Instruction No. 1593
Service Instruction No. 1593
Incorrectly marked alternator belts.
DATE:
May 12, 2025
MODELS AFFECTED:
TEO-540-C1A
TIME OF COMPLIANCE:
N/A
This Service Instruction is in response to incorrectly marked alternator belts having reached the field on engines or as spare parts.
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