EFIS-D100 Installation Guide - Dynon Avionics

Autopilot Installation and Configuration
STEP 8 – ROLL SERVO FLIGHT TUNING
This set of procedures tunes the settings in the AP > ROLL SERVO menu for the particular
flight characteristics of the aircraft in heading holds and turns.
Note: While this procedure is described assuming you are using HDG mode – where the AP’s
goal is to keep the aircraft’s magnetic heading aligned with the HDG bug – it can be performed
in TRK mode – where the AP’s goal is to keep the aircraft’s ground track aligned with the bug –
instead.
Step 8a – Verify preferred Turn Rate Limit and Bank Angle Limit
On the EFIS, perform the following:
SETUP > AP > ROLL SERVO
Verify that the TRN RT LMT and BANK LIMIT parameters are set to values you are
comfortable with.
If you wish to change either of these values prior to or during flight, push DOWN▼ to select
the value, and then DEC - or INC + to modify it.
Step 8b – Ensure that the aircraft is in trim.
Because this test procedure tunes only the Autopilot’s control of roll (so that roll performance
can be isolated), only start the procedure when the aircraft is in neutral trim. During the
following procedures, ensure that your altitude stays constant.
Step 8c – Engage the AP in HDG mode
On the EFIS, perform the following:
EFIS > AP > HDGOFF.
The EFIS synchronizes the HDG bug to the current heading, the Autopilot engages with the
heading bug as its target, and the indicator turns to HDGON.
If you have an AP74 installed and configured, the following performs the same function:
Push HDG button (activates ROLL servo); ensure that the red HDG indicator lights are on.
Ensure that the ALT indicator lights are off; push the ALT button if they are not.
Push the AP button to engage in HDG mode.
The AP status indicator at the lower left of the EFIS screen displays: AP:HDG-OFF
Step 8d – Allow a few minutes of stable flight under AP control
Note that the AP is only flying in Heading Hold Mode, so you will need to control the aircraft in
pitch. Ensure that you are not affecting the Autopilot’s control of the roll axis, so you can
determine the AP’s heading hold and change performance.
Step 8e – Adjust roll servo TORQUE and/or SENSITIVITY values as needed
On the EFIS, observe the AP status indicator (lower left corner - AP:HDG-OFF) while the AP
flies. If the HDG indicator is frequently highlighted yellow, that is an indication that the Roll
Servo is slipping and the torque needs to be increased. Occasional slips due to turbulence are
acceptable.
If necessary, adjust the TORQUE value in the EFIS > SETUP > AP > ROLL SERVO menu.
EFIS-D100 Installation Guide 6-25