Autopilots have been around nearly as long as aircraft themselves. The fundamental concept of an autopilot remains the same: to automatically provide pitch, roll and yaw forces without the pilot touching the flight controls. What has changed over time is the system and technology behind an autopilot — how it works and the hardware it uses to generate those pitch, roll and yaw forces. Using design elements from the advanced GFC 700 autopilot that is found on many business aircraft, Garmin created the GFC 500 and GFC 600 digital autopilots that are now available for thousands of general aviation aircraft.
Improving upon a decades-old design comprised of brushed motors that had a tendency to wear over time, thus requiring costly maintenance or overhaul intervals, Garmin designed the GFC 500 and GFC 600 with brushless DC motors. These contactless motors result in a powerful servo with fewer inspection requirements, reduced maintenance costs, and aircraft downtime. This results in improved long-term performance, reliability and operating costs for aircraft owners.
Traditional autopilot servos typically contain fail-safe design elements such as a mechanical slip clutch or shear pin to ensure pilots can always overpower an autopilot. A variety of factors, including fatigue, can cause a shear pin to break, necessitating a repair. Garmin eliminated the need for mechanical slip clutches and shear pins, incorporating a feature that decouples the motor drives when the autopilot is turned off or disengaged, providing virtually no control system friction. That way, pilots can easily hand-fly or override the system without fighting the controls.
Each Garmin autopilot servo is also monitored by its own built-in microprocessor, providing the “smart” logic to significantly improve sensor performance, response and self-monitoring capabilities. A truly smart, digital solution with potentially safety-enhancing and cost-reducing benefits in the long run.
To date, dozens of legacy aircraft are approved for these retrofit autopilot solutions with many more coming soon. For additional information about the GFC 500 and GFC 600 autopilots, visit the Garmin website at garmin.com/aviation.