TT31 Transponder Installation Manual
8 May 2017
00455-00
Issue AQ
______________________
Trig Avionics Limited
Page 31
12. ADS-B Compliance
TT31 transponders with software version 3.1 and above include support for Extended Squitter ADS-B
out which is compliant with DO-260B. The TT31 is a B1S ADS-B transmitter.
12.1 ADS-B Parameters Supported
The following table lists the ADS-B parameters that are transmitted by the TT31 transponder when
connected to an appropriate GPS receiver.
Parameter
BDS Register
SPI
0,5
Emergency Indicator
0,5
Barometric Altitude
0,5
Quality Indicator (NIC)
0,5
Airborne Position
Latitude
0,5
Longitude
0,5
Quality Indicator (NIC)
0,6
Surface Position
Latitude
0,6
Longitude
0,6
Surface Ground Speed
0,6
Surface Ground Track
0,6
Aircraft Identification
0,8
Airborne Ground Velocity
0,9
Geometric to Barometric Altitude Difference
0.9
Geometric Vertical Speed
0.9
Squawk Code
6,1
Emergency Status
6,1
Quality Indicator (NACp, NACv and GVA)
6,5
Quality Indicator (SIL and SDA)
6,5
Version Indicator
6,5
Surface Length/Width
6,5
Surface Antenna Offset
6,5
In all cases, uncompensated latency due to the transponder is less than 10 milliseconds. Analysis of the
system latency should add this to the latency of the GPS system and the transmission time of the
position data from the GPS to the transponder to determine the overall latency.
12.2 FAA 91.227 Compliance
The TT31 transponder is certified to TSO-C166b and meets the requirements of AC 20-165B when
directly connected to the GPS units listed below, and will form the basis of a 14 CFR 91.227 compliant
ADS-B installation.
The following combinations are available under Trig STC program for certified aircraft.
