Dynon Avionics EFIS-D100 Installation Guide - Manual (Page 62)

Autopilot Installation and Configuration
6-26 EFIS-D100 Installation Guide
If you have adjusted the roll servo TORQUE value to 100% and are still seeing frequent
slips, you may need to move the linkage attachment point on the roll servo 1 hole closer
to the shaft. When doing this, take all precautions to ensure that an over center condition
cannot occur, while still preserving the control surfaces’ full range of motion. If a
mechanical solution is not possible, you may wish to try a higher strength servo (e.g., if
you have an SV32 installed, try swapping for an SV42).
After verifying that the TORQUE value is set appropriately, watch closely for
AP “wandering” around the target heading or track. The AP should keep the
inverted triangle of the heading bug closely aligned with the triangle of the
numerical magnetic heading indicator (as shown at right). If flying in TRK
mode, the AP should keep the inverted triangle of the bug (colored magenta to signify GPS
mode) aligned with the magenta triangle of the current ground track.
If excessive wandering is observed, increase the SENSITIVY parameter in the EFIS >
SETUP > AP > ROLL SERVO menu. If the AP control seems “twitchy” or aggressive,
decrease the SENSITIVITY value. All adjustments of SENSITIVITY should be done in
increments of 1 or 2, allowing you to notice subtle changes in control.
Step 8f – Change the heading bug 90 degrees from the current heading
Change the HDG bug to 90 degrees to the left or right of current heading via any of these
methods:
 On the EFIS, enter the EFIS > AP > BUGS > HDG menu, and press INC + or DEC - to set
desired heading.
On the AP74, press the VALUE knob (or just begin rotating knob, if you have configured
the VALUE KNOB settings to allow for that) until the HDG bug adjustment window is
displayed. Rotate the knob until the desired target heading is set.
On the HS34, rotate the HEADING knob.
As soon as the heading bug is changed, the AP begins changing the aircraft’s direction to follow.
Step 8g – Verify roll TORQUE and SENSITIVITY settings during turn(s)
During an AP-commanded turn, observe the AP status indicator as you did in step 8e; if
excessive slipping is observed (indicated by a yellow highlight around the HDG status), then
increase the roll servo’s TORQUE parameter.
Repeat the 90 degree AP-commanded turns and torque adjustments until the HDG indicator does
not display a slip indication.
Continue performing AP-commanded turns, and observe the overall behavior of the aircraft. If
the aircraft wallows, or rolls out of turns slowly as it reaches the target heading, that is an
indication that the Roll Servo SENSITIVITY needs to be increased. If, upon reaching the target
heading and the stick “twitches” excessively, that is an indication that the Roll Servo
SENSITIVITY needs to be decreased.
You should be able to find a SENSITIVITY value that is acceptable for both heading
holds and turns in smooth air. You may, however, find that in periods of extended
turbulence, a lower SENSITIVITY value must be set.