Trio Avionics Pro Pilot - Manual (Page 65)

Trio Pro Pilot Manual 3.8
65
Chapter 14
Horizontal and Vertical Gain
Horizontal Navigation Gain
The response of the aircraft to horizontal navigation system commands can vary considerably depending
upon a number of factors. The mass of the airplane, the sensitivity to control movement, and the way
the control surfaces are rigged can affect aircraft response to control movement.
In most cases, the factory default settings will be satisfactory, however, fine adjustments to tune the
response to a particular installation are provided to ensure optimum tracking performance.
The Pro Pilot allows the pilot to adjust three system parameters to achieve optimum horizontal navigation
performance. Adjustment may be needed if the aircraft wanders more that +/- 1 or 2 degrees in the CRS
mode, or in the TRK mode, if the XTK value displayed on the autopilot tends to exceed .03nm for long
periods, or there is excessive hunting around the desired track.
For instance, assume that you are flying in the CRS mode (in smooth air) and you find that the aircraft
“wanders” a few degrees to the left and right. You may wish to enter the calibration screens to adjust the
CRS gain to lessen the deviations.
Additional gain may improve the performance, but be aware that too much or too little gain may also
cause oscillations. You should adjust it to find the “sweet spot” for your aircraft where it holds the course
best. These settings are saved in non volatile memory and need not be adjusted again.
The three adjustable parameters that are available to the pilot for horizontal response are:
1. CRS Gain: Fine course quality. This adjustment controls sensitivity to course commands when
in the Course (CRS) and Track (TRK) modes, and within 5 degrees of the desired course and
.07 nm of the desired track (DTK). It has no effect outside of 5 degrees of the selected course
heading or greater than .07 nm of the DTK.
2. TRK Gain: Fine track quality. This adjustment controls how sensitive the system is to
commands when in the Track (TRK) mode, and within .07 miles of the track centerline. It has no
effect outside of .07 miles.
3. PULL IN: Pull In controls system response when the aircraft is outside of the .07 miles cross
track error or showing greater than 5 degrees of error to the selected course. This is essentially
a coarse gain used to bring the system within range of the fine tracking gain settings.
These settings should normally have to be set up only once, during your first test flight.
Changing Horizontal Navigation Gains
To enter the SET HNAV GAINS selection, perform the following steps:
1. Enter the PREFERENCES SETTINGS menus as
detailed previously and select the SET HNAV GAINS
menu.
2. Press and release the H MODE button. The arrow
will be placed at the CRS setting value. Adjust this
setting only while in the CRS mode. To change
this value, rotate the encoder to the desired setting.