King Air: Garmin G600 with Sperry SPZ-200 Autopilot

The Duncan Aviation Sacramento Avionics shop performed a Garmin avionics upgrade on a King Air. We removed the analog equipment on the pilot’s instrument panel and installed a Garmin G600 Integrated 2-Display System in accordance with the Garmin AML STC.

During the process of the installation we learned:

• Annunciators would need to be added.
• Existing vertical and directional gyros would control the autopilot without visual indication.
• The existing altitude preselector would remain in the aircraft.

The SPZ-200 autopilot is an analog autopilot, the altitude preselector will not display on the G600 Display. In order for the Flight Director modes to be displayed, annunciators were added. The GRS-77 AHRS that is included in the G600 installation can be incorporated with SPZ-200 autopilot.

Garmin will not be supporting any AHRS interface with the SPZ-200 autopilot. This portion of the installation will have to be signed off via field approval FAA Form 337. 

AHRS: Attitude and Heading Reference System        

AML: Approved Model List

FAA: Federal Aviation Administration

STC: Supplemental Type Certificate