Trio Avionics Pro Pilot - Manual (Page 29)

Trio Pro Pilot Manual 3.8
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In such case, after approximately 7 seconds without signal
the Pro Pilot displays the NO GPS message.
Since the Pro Pilot is no longer able to provide the navigation function, the ROTARY ENCODER can be
used to control the aircraft turn rate, or to correct for gyro drift to effect a straight ahead flight path
The Pro Pilot servo is still engaged so the aircraft is being controlled in the “wing leveler” mode (aircraft
roll stabilization). Without the GPS signal, the Pro Pilot solid-state gyro lacks a precise external
reference and after several minutes may begin a slow change in heading due to gyro drift. In order to
change the heading slightly to stop the drift, the pilot needs to monitor the compass heading and rotate
the ENCODER either left or right to maintain the desired heading.
Course Mode Example
As the flight progresses the destination, Class B
airspace is entered after getting the appropriate
clearances.
Flying along on the pre-selected
010 degree TRK,
Approach Control requests “Turn right 30 degrees for
clearance from other traffic.”
This turn can be accomplished in one of two ways:
1. The CRS mode is selected by pressing the MODE pushbutton momentarily. The following
changes in the display are noted:
 The
TRK LED extinguishes, the CRS LED
is illuminated
 The
BTW field changes to CRS
 The
TRK field changes to <010
 The
CRS and TRK fields are, for the
moment, identical (010)
Since the controller wants 040 degrees (formerly 010
degrees), a 30 degree turn to the right is needed. The
desired CRS is 040 degrees
so the ROTARY
ENCODER is turned clockwise until 040 is displayed
as the CRS value. The Pro Pilot turns the airplane
until both the track (TRK) and the course (CRS) are
the same (040).