Aviation safety issues and actions

Autopilot advice, limitations cautions and warnings (written and audible)

Issue number: AO-2015-105-SI-02
Who it affects: Aircraft owners and operators of aircraft fitted with the Garmin G1000 avionics system and GFC700 autopilot.
Issue owner: Garmin
Operation affected: Aviation: General aviation
Background: Investigation Report AO-2015-105
Date: 17 April 2018

Safety issue description

The lack of manufacturer written advice, limitations, cautions, or warnings (written or aural) about autopilot response to manual pilot control inputs meant that pilots may be unaware that their actions can lead to significant out of trim situations, and associated aircraft control issues.

Response to safety issue by Garmin

The avionics manufacturer indicated that since all autopilots work the same way, it was common knowledge for pilots not to manually manipulate the flight controls with the autopilot on. Therefore, any advice, limitations, or warnings about the issue would not be required. They also indicated that the presence of a limitation, warning, or caution is generally left up to the certifier of the equipment in the airplane [in this case Cessna].

ATSB comment/action in response

Advanced avionics systems and autopilots are now fitted to many aircraft used by relatively inexperienced pilots. Therefore it is important that every opportunity is taken to inform them of the potential danger posed by manual manipulation of the flight controls with the autopilot on.


Action organisation: Garmin
Action number: AO-2015-105-SR-006
Date: 17 April 2018
Action status: Released

ATSB safety recommendation Garmin

The ATSB recommends that Garmin, in conjunction with aircraft manufacturers, takes action to ensure that all aircraft types fitted with their autopilots have the limitations, cautions and warnings documented in the aircraft’s operating manuals. Further, the ATSB recommends that Garmin consider the use of audible warnings to enhance pilots’ awareness of mistrim situations brought on by the autopilot system.

Current issue status: Safety action pending
Last update 17 April 2018