Heading Data Source Failure; Elevator Mistrim (Autotrim) - Piper CHEROKEE ARCHER II Pilot Operating Handbook

HEADING DATA SOURCE FAILURE

Without a heading source to the navigator, GPSS will not be provided to the autopilot for heading legs. Navigator
map cannot be oriented heading up.
Track information will be displayed on the G5.
1. Autopilot ............................................................................................ SELECT different lateral mode

ELEVATOR MISTRIM (AUTOTRIM)

(Amber TRIM UP or TRIM DOWN displayed on the G5.)
Indicates a mistrim of the elevator while the autopilot is engaged. If a pitch trim servo is not installed, refer to the
normal procedures section of this AFMS, MANUAL PITCH TRIM WITH AUTOPILOT ENGAGED. If a pitch trim
servo is installed, the autopilot will normally trim the airplane as required. However, during rapid acceleration,
deceleration, configuration changes, or near either end of the elevator trim limits, momentary illumination of this
message may occur. If the autopilot is disconnected while this message is displayed, high elevator control
forces are possible.
Do not attempt to overpower the autopilot in the event of a pitch mistrim. The autopilot servo
will oppose pilot input and will cause pitch trim to run opposite the direction of pilot input. This
will lead to a significant out-of-trim condition, resulting in large control wheel force when
disengaging the autopilot.
If a pitch trim servo is not installed:
1. Refer to the normal procedures section of this AFMS, MANUAL PITCH TRIM WITH AUTOPILOT
ENGAGED.
If a pitch trim servo is installed:
Momentary display of the TRIM UP or TRIM DOWN message during configuration changes or
large airspeed changes is normal.
1. Control Wheel ............................................................................................................. GRIP FIRMLY
Be prepared for significant sustained control forces in the direction of the mistrim annunciation.
For example, TRIM DOWN indicates nose down control wheel force will be required upon
autopilot disconnect.
2. AP DISC / TRIM INT Button .........................................................................PRESS AND RELEASE
3. Manual Elevator Trim ....................................................................................... RE-TRIM as required
Electric pitch trim should be considered inoperative until the cause of the mistrim has been investigated and
corrected.
190-02291-07 Rev. 4
WARNING
NOTE
WARNING
AFMS – GFC 500 Autopilot in Piper PA-28 Series
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