TT21/TT22 Settings
These can be found in the Set Menu, General Setup, TT22 menu when controlled by the EFIS.
Setting
Required Selection
GPS Input
GRT Safe-Fly NN33
(select NexNav on non-GRT controllers)
GPS/TIS Rate
38400
GPS Certification Level
C
GPS NACv (m/s)
< 10
Wiring
Safe-Fly GPS Pin
Trig TT21/22 Pin
Notes:
19 – Serial Out 1
5 – GPS Input
If the GRT Trig adapter is installed on the
TT21/TT22, the connection is made to pin 5 of
this adapter. The data will pass through the
adapter into the transponder. The adapter
software must be version 5 or higher, as reported
on the Set menu, General Setup,
TrigTT22/EchoUAT menu (near the top of the
General Setup settings).
Post-Installation Checkout - Verifying Trig TT-22 is Receiving GPS Data
When a GPS data stream with a valid position is being received by the TT22, the TT22 reports the
received GPS position to the controller. When a GRT EFIS is the controller, this is reported in the Set
Menu, General Setup, TT22 page on the GPS Position line. If this line shows a latitude and longitude,
the position data is being received from the GPS and will be used for ADS-B out. If this line indicates
anything else, the TT22 is not receiving valid position data and will not transmit ADS-B out. An FAA
performance report should also be requested after flying the airplane.
Trig TT31
Note: All steps in the “Safe-Fly/SPC Configuration” section above must be completed before the
following settings are made.
Use of the Safe-Fly GPS for the TT31 is approved by GRT Avionics when installed and configured as
described in this section for experimental category airplanes. This installation meets the requirements
of FAR 91.227(c), when wired as shown below, and configured as indicated.
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Safe-Fly 2020 GPS – Rev P GRT Avionics, Inc
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