As an example, while Garmin's GFC 500 retrofit autopilot has become perhaps the most common in the piston world with a wide-reaching AML-STC, there isn't a similar retrofit autopilot for turbines.

Owners of nearly 6,000 small aircraft in the USA may soon need to update their Garmin autopilot software due to a defect that could cause the autopilots to make uncommanded flight-control inputs. That ...