Trio Pro Pilot Manual 4.1
41
Chapter 9
GPSS and GPSV Operation
GPSS and GPVS Defined
GPSS
and
GPSV
are acronyms for “GPS Steering” and “GPS Vertical steering”. These features use the
ARINC 429 data stream provided by some GPS receivers and EFIS systems.
When ARINC signals are available and the Pro Pilot is in the Track (
TRK
) mode, the autopilot follows the
roll commands (
GPSS
) and vertical commands (
GPSV
) issued by the originating GPS receiver or EFIS.
In addition to the ARINC data, the Pro Pilot also requires the AVLINK or NMEA RS-232 data input
for other features and functions to operate properly.
The ARINC 429 data signal requires 2 wires for data, as opposed to the RS-232 where the data is
carried on one wire (the common power ground provides the return data path).
The Pro Pilot can utilize the ARINC signal from non-WAAS GPS receivers and will accurately track a
flight plan, as well as the lateral profile of certain GPS approaches.
GPPS and GPVS Considerations
Precision GPS approaches (RNAV) require the use of a certified WAAS receiver (such as the
Garmin 400W/500W series) to be able to fly the vertical profile of an approach. Garmin WAAS
receivers also provide guidance for the Pro Pilot to fly procedure turns and certain holding
patterns.
The IFR approved UPS GX series of GPS receivers have a GPSS type signal interface available
on a dedicated RS232 channel into the autopilot, however no vertical (GPSV) capability exists
with these receivers.
When connected to a compatible EFIS (and in the
TRK
mode), the Pro Pilot may also obtain
lateral and vertical guidance from the EFIS.
On some compatible EFIS systems the altitude and heading bugs can also be used to generate
the lateral and vertical guidance to the Pro Pilot.
NOTE
: The ARINC lateral and vertical guidance is only accepted from the GPS or EFIS when the
autopilot is in the
TRK
mode.
If the autopilot is placed in the
CRS
or
INT
modes:
The ARINC input is disregarded
The lateral and horizontal flight paths are selected at the autopilot front panel
Lateral navigation reference is provided via the RS-232 NMEA / AVLINK signal
Vertical guidance is selectable at the autopilot based on barometric pressure data provided by
the autopilot system by selection of the
AS/VS
Mode.