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

TIME OF COMPLIANCE:

For Engines with the Original EIS: Before further flight for engines with more than 100 hours, Time-In-Service on the EIS. For Engines with more than 50 hours, but less than 100 hours, Time-In-Service on the EIS: Within the next 10 hours of operation. For Engines with a replacement EIS: Not to exceed 50 hours, Time-In-Service on the EIS.

REASON FOR REVISION:

Revised MODELS AFFECTED. Added ICA statement. Remove Rev R as terminating action and update the date to the present year.