(2023) Service Bulletin 23015 Rev A: GSM 86 Cable Retention Pins in GFC 600 Installations

PRODUCTS AFFECTED:

Garmin GFC 600 Automatic Flight Control System (STC SA01844WI, Master Drawing List, Revisions 1 through 56) installed in the aircraft listed below that use 011-01904-XX and 011-02490-XX Garmin GSM 86 Servo Gearboxes with capstan output devices that use 233-00075-01 and 233-00075-02 Cable Retention Pins are affected.

• Textron Aviation Inc. (Cessna) Model 525
  
• Textron Aviation (Beechcraft) 90 Series
  
• Pilatus PC-12, PC-12/45, and PC-12/47
  
• Textron Aviation Inc. (Cessna) 441

CERTIFICATION AUTHORIZATION:

AML STC SA01844WI MDL Revision 57

COMPLIANCE:

Compliance with Service Bulletin 23015 is recommended at a maintenance interval not to exceed 1 year.

PURPOSE:

In the event of the loss of the clutch retaining bolt, the output shaft drive pin may become partially disengaged causing the capstan to bind.