Advanced pitch gain and rate adjustments – Dynon Avionics FlightDEK-D180 Installation Guide User Manual

Page 103

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Autopilot

Installation and Configuration

FlightDEK-D180 Installation Guide

8-19

loads, but low enough that the pilot can override the AP should the need arise. If the servo slips
continuously, the AP cannot fly the aircraft. Torque is specified in % of maximum the servo is
capable of exerting. Minimum: 10%, maximum 100%, default: 100%.
On the EFIS, perform the following:

 If not already in the SETUP > AP menu, enter the menu and select PITCH SERVO and press

SEL►

 (TORQUE value is highlighted)
 Press DEC - and INC + to adjust TORQUE to preferred initial setting for the aircraft.

It may take some experimentation to find the right value for your aircraft, but if you are
comfortable overriding the default value of 100%, it is safe to leave that setting at the default
value. To test servo override, exit the SETUP > AP menu and return to the main EFIS menu.
Center the aircraft controls. Enter the EFIS > AP menu and press ALT

OFF

. Note that the mode

toggles to ALT

ON

, the ALT bug synchronizes to the current altitude, and the pitch servo

engages. Ensure that the controls do not deviate far from center.

If you have an AP74 installed and configured, you can accomplish this same procedure
by doing the following: Push the ALT button to ensure that it is lit; push the HDG button
until it is not lit. Push the AP button to engage the AP in Altitude Hold mode.

Now, take the controls and override the servo by moving to either pitch down or pitch up
(remember, you are only overriding the pitch servo, so you should feel no resistance in the roll
axis). Ensure that you are comfortable with the amount of force it takes to override the servo. If
you are not, decrease the roll servo TORQUE value by 10% and repeat the test.

Step 4b – Set Pitch Servo Sensitivity: The PITCH SERVO > SENSITIVITY parameter
specifies the how fast or slow the AP responds to deviations between commanded altitude and
actual altitude. If Sensitivity is set too low, the aircraft will “wallow” during changes in altitude.
If Sensitivity is set too high, the aircraft will be “twitchy,” with frequent, fast, aggressive
adjustments. Sensitivity is specified in digits. Minimum: 1 (low sensitivity), maximum: 25 (high
sensitivity), default: 10.
This parameter can be tuned in flight; leaving it at the default of 10 is sufficient for initial setup.
If the autopilot is not as “decisive” as you’d like, increase this value; if it is too aggressive,
decrease it.
On the EFIS, perform the following (continuing from TORQUE):

 DOWN▼ > (SENSITIVITY value is highlighted)

 Press DEC - and INC + to adjust SENSITIVITY to preferred initial setting for the aircraft.

Advanced Pitch Gain and Rate Adjustments

There are several additional advanced parameters that can be used to fine tune the performance
of the pitch axis. They should be considered secondary to the primary Pitch Axis Sensitivity
adjustment. When used, they should be adjusted in the following order:

 Pitch Gain: Use only after sensitivity is set as well as it can be. Increase gradually if airplane

does not settle on altitude. The default setting is 20.

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