TruTrak Sorcerer RV10 AP100 - Manual (Page 13)

Sorcerer, RV 10, AP 100 Autopilot Installation Manual 11 TruTrak Flight Systems
May 2009 8300-010 Rev B
The next setup screen is MICROACTIVITY. The MICROACTIVITY setting in most aircraft will be left at zero (0). Micro
activity is used only in aircraft in which a slow wing rock has been observed in very still air. Sometimes there will be a small
amount of lost motion in an aircrafts control system, and the micro activity setting is a way to compensate for the lost motion.
Once the desired MICROACTIVITY has been selected, push and release the encoder knob to exit the lateral setup mode.
Having set the autopilot for its proper roll response, it is time to move to the pitch axis adjustments. Press and hold the ALT
button until VRT ACTIVITY is shown on the display, along with an underlined value. In the same manner as was done for the
roll axis, use the knob to find a setting which results in the appropriate response. Again, too high a value will be jittery or
oscillatory and too low a setting will be sluggish and unresponsive. Having found the desired VRT ACTIVITY setting, press
and release the UP control on the vertical speed rocker to advance to the next setup screen.
In a manner similar to the lateral axis, rotate the knob to choose a torque setting sufficient to fly the aircraft in light to moderate
turbulence without slipping the servo, yet not so high as to be difficult to override manually. Having selected this value, press
and release the UP control on the vertical speed rocker to advance to the next setup screen.
The next screen shows selections for MIN AIRSPD. The minimum airspeed value is the slowest indicated airspeed the
autopilot will fly, independent of what it is commanded to do. This airspeed value should be safely above stall speed (knots
IAS) yet slower than normal approach or climb out speeds. Select the value, and press the UP control on the vertical speed
rocker to advance to the next setup screen.
The next setup screen is the MAX AIRSPD screen. The maximum airspeed value is the fastest indicated airspeed the autopilot
will fly, independent of what it is commanded to do. This airspeed value should be safely below the red line speed (knots
IAS) yet above normal cruising speeds. Select the value, and press the UP control on the vertical speed rocker to advance to
the next setup screen.
The next setup screen is the NORM CLIMB field is the airspeed (knots IAS) which would be normally used in a climb,
typically the cruise climb airspeed for the aircraft. This value shows up as the default airspeed (which can be changed as
desired while climbing) in the altitude selector function. Select the normal climb airspeed, and press the UP control on the
vertical speed rocker to advance to the next setup screen.
The next screen is the STATIC LAG field. It is set to 0 at the factory but can vary between 0 and 2 to suit a particular static
system. The value 0 assumes a static system with very little “lag”; the value 2 assumes a fairly large amount of lag. To
diagnose the lag of a particular system, it is necessary to be in the altitude hold mode of the autopilot, so prior to setting this
field, push and release the encoder knob to exit the pitch setup screen. Click the ALT button to enter altitude hold. This puts
the autopilot into altitude hold mode at the current altitude.
Once the autopilot is in altitude hold mode, re-enter the vertical setup mode by holding the ALT key. Use the UP control on
the vertical speed rocker to cycle over the choices already made until the STATIC LAG display is again on the screen. In still
air, straight and level flight, in altitude hold mode, observe whether the altitude appears to oscillate, or “hunt” up and down. If
this is the case, it may be caused by several factors, one of which is the amount of lag in the static system. Increasing the
STATIC LAG value to a 1 or a 2 may cure the problem; however this should be set to the smallest value that satisfactorily flies
the aircraft in the pitch axis, as the larger the value the less responsive the autopilot will be to vertical commands or altitude
error. Other possible causes of hunting in altitude hold are “lost motion” in the aircraft controls or too low a level of vertical
activity setting. Excessive lag in the static system itself can be caused by undersized static ports, improperly placed ports, long
static lines, or especially by attached equipment with large static reservoirs. The autopilot can be adapted to cover a wide range
of static systems, but in truly extreme cases it may be necessary to provide a separate static line for the autopilot so that other
equipment attached to the port does not degrade the autopilot’s performance. Press and release the UP control on the vertical
speed rocker to advance to the next setup screen.
The next setup screen is MICROACTIVITY. The MICRO ACTIVITY setting in most aircraft will be left at zero (0). Micro
activity is used only in aircraft in which there is a slow pitch oscillation that is very small in magnitude. Sometimes there will
be a small amount of lost motion in an aircrafts control system, and the micro activity setting is a way to compensate for the
lost motion. Press and release the UP control on the vertical speed rocker to advance to the final pitch setup screen.
The HALF-STEP setting in most cases will not need to be changed. If the half step setting is set to Y (yes), then the pitch
servo will now have higher resolution, and take smaller steps. While this setting will make the servo take smaller steps, it will
decrease the amount of available torque. This setting should be left at N (No), unless it is observe that the nose moves up and
down very slightly while in altitude hold in very still air. Once this setting has been done, push and release the encoder knob to
exit the pitch setup.