Dynon Avionics SkyView Autopilot In-Flight Tuning Guide - Manual (Page 9)

SkyView Autopilot In-Flight Tuning Guide - Revision B 3-1
3. Roll Axis – TRK and Turns Procedure
Overview
This procedure tunes the roll autopilot servo and thus, the flight characteristics of the aircraft in
heading holds and turns. This procedure should be performed with the autopilot roll axis in
track (TRK+ALT) mode, where the purpose of the autopilot is to keep the aircraft’s GPS ground
track aligned with the track bug (as well as hold altitude). Before executing this procedure:
The autopilot controls should be changed to SIMPLIFIED mode
(SETUP MENU > AUTOPILOT SETUP > AUTOPILOT CONTROLS)
The Roll Axis tuning process can be summarized as follows:
Change TRK command by approximately 90 degrees, and observe the results. The AP should
promptly roll into a turn towards the new TRK and smoothly reach the commanded TRK with
little or no overshoot.
Note: be sure to observe ground track (TRK) and not heading (HDG) during this
procedure.
If the AP is slow to respond to the TRK changes, increase the ROLL AXIS SENTIVITY and watch
for improvement. In some cases this may require a fair amount of increase, but be cautious
about changing it too quickly. Sensitivity adjustments alone may not completely eliminate
overshoot. If increasing sensitivity no longer improves performance, ROLL GAIN may be used to
fine tune the roll axis. Too much sensitivity may cause AP responses to be “twitchy”. Reduce
ROLL SENSITIVITY if this occurs. Too much ROLL GAIN will result in a rough ride.
In particular, if the autopilot cannot keep up with the flight director roll command bar, ROLL
SENSITIVITY should be increased. At some point the AP will track the command bars, but follow
behind them. ROLL GAIN will reduce the gap.
Caution: Large changes in ROLL SENSITIVITY with the autopilot engaged can result
in large servo movements.