TruTrak Sorcerer RV10 AP100 - Manual (Page 12)

Sorcerer, RV 10, AP 100 Autopilot Installation Manual 10 TruTrak Flight Systems
May 2009 8300-010 Rev B
With autopilot and yaw engaged push on tail and rudder must move in
direction you have pushed.
First Flight
The first flight should be done after having completed all the setup and testing on the ground. For the first flight, it is important
that the GPS unit is properly functioning with the autopilot, so that the dynamics of flight can be set without consideration of
the calibration of the magnetic backup system. As discussed earlier, when there is proper connection to the serial input of the
autopilot, the display will show a flashing asterisk “*” in the display below the words GPS OK; once taxi speed exceeds 10
knots, the display will change from GPS OK to TRK if the GPS unit has achieved a position fix and sufficient groundspeed. If
this does not occur on fast taxi speeds, it is best to diagnose the problem prior to first flight of the autopilot.
The two activity adjustments (LAT ACTIVITY and VRT ACTIVITY) determine how briskly the autopilot responds to roll and
pitch disturbances. They can be adjusted, in flight, over a wide range; thus the autopilot can be tailored to adapt to any aircraft
installation.
Each of the two activity adjustments covers a numeric range of 0 to 24. Unless the value for a particular aircraft is provided by
TruTrak, it is advisable to start with a setting of zero and work up from there. Most installations would ultimately require
somewhat higher settings.
Prior to takeoff on the first flight, a barometer set will be required. (Not used in RV 10, AP 100 models) With the autopilot off
press and hold the SEL button for approximately three seconds, to show the BARO SET screen (take care not to accidentally
enter the ALT SELECT screen by mistake). The words BARO SET will appear immediately. Continue holding until
ALTITUDE appears below BARO SET. This will insure that the ALT SELECT screen will not be selected by mistake. Use
the encoder knob to adjust the setting of the barometer. The default value will always be 29.92. Having set the autopilot’s
barometer to agree with the current barometer setting, push and release the encoder to enter the barometer setting. If the
current altitude is incorrect, adjust the current altitude. Press and release the encoder to enter the current altitude and exit the
barometer setup screen.
On the first flight, manually fly the aircraft to a suitable area for testing. Engage the autopilot using the AP switch. Observe
that the SEL field now shows the captured present ground track (shown after TRK on the display) and the SVS (selected
vertical speed) field shows the approximate present rate of climb or descent in feet per minute. Use the vertical speed rocker to
set the selected vertical speed to zero. Press and hold the TRK button for a few seconds until LAT ACTIVITY is shown on the
display, along with an underlined value. Rotate the knob to select the value zero (0), and observe the resulting control
movement. Increase the value one setting at a time, taking time to observe an increasing level of control response. At some
point, if too high a setting is chosen, the autopilot will be jittery and over-active. Back the setting down until the autopilot is
responsive but not over-active. It is best if these adjustments are made in conditions of moderate turbulence (the Sorcerer loves
turbulence) so as to make it easy to observe the response of the autopilot to disturbances. It will be noted that a fairly limited
range of activity setting will be acceptable; too low a value will result in sluggish response, while too high a value will result in
nervous, inappropriate response. Within this acceptable range there is room for individual preference; some people prefer a
more aggressive autopilot than others. It should be noted that any builder can accomplish this adjustment procedure and no
professional is required.
Once the desired LAT ACTIVITY level is established, press and release the UP control on the vertical speed rocker.
Next, the LAT TORQUE field is adjusted. Again, it is best that this be done in light to moderate turbulence. The reason is that
more torque is required of the autopilot in turbulence than is the case in still air, because the velocity of the servo is greater as
turbulence requires more rapid servo movement. This means that when activity is set to the high end of the acceptable range, a
higher torque setting will be required.
The reason for setting LAT TORQUE to a setting less than its maximum (12) is to reduce the current draw of the servo and to
make it easier to override the autopilot should the need arise. Manual override is not normally required, as using the control-
wheel switch or the AP button will disengage the autopilot, but it is best to have a setting of torque which can be comfortably
overridden if necessary. Once the desired LAT TORQUE level is established, press and release the UP control on the vertical
speed rocker to advance to the next setup screen.
The next setup screen is the BANK ANGLE selection screen. Set the desired bank angle that is comfortable, options are LO,
MED, and HI. Once the BANK ANGLE has been selected, push and release the UP control on the vertical speed rocker to
advance to the next setup screen.