Suspected Autopilot Malfunction; Overpowering Autopilot Servos - Garmin G1000 NXI Cockpit Reference Manual

abnormal operation
prominently displayed in amber on the HSI slightly below and to the left of the aircraft symbol
on the CDI as shown in the following figure. Lastly, but at the same time, a 'GPS NAV LOST'
alert message appears on the PFD. Normal navigation using GPS/SBAS source data resumes
automatically once a valid GPS solution is restored.
As a result of operating in DR Mode, all GPS-derived data is computed based upon an es-
timated position and is displayed as amber text on the display to denote degraded navigation
source information as shown in the following figure. If the VSD Inset is selected on the MFD,
'VSD Not Available' will be displayed.
Also, while the system is in DR Mode, some terrain functions are not available. Additionally,
the accuracy of all nearest information (airports, airspaces, and waypoints) is questionable.
Finally, airspace alerts continue to function, but with degraded accuracy.

SUSPECTEd aUToPILoT MaLFUNCTIoN

NoTE: Consult the aircraft documentation for the location of circuit breakers as well
as specifics that may supplement or amplify this procedure.
Mitigating suspected autopilot failure or trim failure:
1) Firmly grasp the control stick.
2) Press and hold the aP dISC Switch. The autopilot will disconnect and power is removed
from the trim motor. Power is also removed from all primary servo motors and engaged
solenoids. Note the visual and aural alerting indicating autopilot disconnect.
3) Retrim the aircraft as needed. Substantial trim adjustment may be needed.
4) Pull the appropriate circuit breaker(s) to electrically isolate the servo and solenoid
components.
5) Release the aP dISC Switch.

oVERPoWERING aUToPILoT SERVoS

In the context of this discussion, "overpowering" refers to any pressure or force applied
to the pitch controls when the autopilot is engaged. A small amount of pressure or force on
the pitch controls can cause the autopilot automatic trim to run to an out-of-trim condition.
Therefore, any application of pressure or force to the controls should be avoided when the
autopilot is engaged.
Overpowering the autopilot during flight will cause the autopilot' s automatic trim to run,
resulting in an out-of-trim condition or cause the trim to hit the stop if the action is prolonged.
In this case, larger than anticipated control forces are required after the autopilot is disengaged.
The following procedure should be added to the preflight checks.
Garmin G1000 NXi Cockpit Reference Guide for the da62
142 190-02622-00 Rev. A