TruTrak Yaw Damper - Manual (Page 6)

TruTrak Flight Systems Yaw Damper Installation Manual
December 2009 4 8300-063 Rev C
First Flight Yaw Damper
The Yaw Damper system requires adjustment of the Yaw Damper parameters. With the
autopilot disengaged, level the aircraft and hand-fly the aircraft in still air. With your feet off the
rudder pedals, confirm that the ball is centered. If the ball is NOT centered, correct the aircraft
out of trim condition before proceeding. Press the appropriate button to engage the Yaw Damper.
Then enter the YD setup screen. Cycle through the settings already completed, until YD
LEVELING is shown on the display. Centering is adjustable from -8 to 8 and has enough
authority to move the ball approximately one and one half times the width of the ball in either
direction. (Coarse adjustment was made using the potentiometer in the yaw damper module
during the earlier Initial Checkout Procedure.) Adjust the centering so that the ball is centered. If
unable to center the ball in flight, confirm Initial check out setting. Once the YD LEVELING has
been set, advance to the next setup screen.
The YD ACTIVITY determines how aggressively the yaw damper responds to yaw disturbances.
Yaw damper activity can range from 0 (off) to 12 (extremely aggressive). For this setting, it is
best to find light to moderate turbulence so the effects can be properly observed. Having found
suitable conditions, gradually increase the value of YD ACTIVITY in order to obtain an
appropriate level of response to yaw disturbances. Too high a value will result in rapid
oscillation, while too low a value will essentially disable the quick response of the yaw damper to
turbulence. Within the acceptable range of operation, there is still room to account for personal
preferences. So long as the yaw damper’s YD ACTIVITY value is not so high as to cause
oscillation, the response is simply set according to preference and comfort. Once the YD
ACTIVITY has been set, exit the setup mode.
With the DII Series autopilot Yaw Damper installations only. The two potentiometers that are
needed (see schematic) serve the function of the Yaw activity and the in-flight ball centering.
The normal operation of the autopilot will turn the yaw damper on any time the autopilot is
engaged, and the yaw damper will stay on after the autopilot is disengaged. During final
approach and the diminishing of the airspeed below the MIN AIRSPD setting, the yaw damper
will automatically disengage. To disengage the yaw damper prior to that point, simply use the
YD or TRK button to toggle the yaw damper off. When the autopilot is in the Off mode, the YD
or TRK button acts as a yaw damper on/off toggle function and the display will indicate
YD ON
or YD OFF.
This concludes the in-flight setup of the TruTrak Yaw Damper.