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The TT31 is a highly efficient class leading transponder. It’s easy to use and operate, with a clear bright display and simple user interface. Features include a flight timer, stop watch and altitude monitor (can alert you of a deviation from your selected altitude). The TT31 includes data link support for the U.S. TIS traffic service, uplinked from approach radars. TIS traffic can be displayed on a variety of portable and panel mount displays, coverage includes most US terminal areas.

Mode A and C transponders are now being replaced by Mode S transponders, this technology is optimised for tomorrow's airspace requirements. The introduction of ADS-B surveillance technology means the modern transponder has now become the hub of future airspace compliance requirements. Here the TT31 remains the transponder of choice, it was the world's first transponder certified to TSO C166b. This is latest FAA standard for the U.S. 2020 ADS-B mandate and demonstrates Trig's advanced levels of compliance. It’s worth remembering that to receive all ADS-B In transmissions in the U.S. the FAA requires a functioning certified ADS-B Out device, fitting a Trig TT31 ensures a full ADS-B In picture.

The TT31 uses half the electrical power of legacy transponders, whilst still transmitting at a higher signal power, its efficient design reduces waste heat in the avionics stack. This reduces the load on the aircraft electrical system improving overall reliability. The flexible power input means that both 14 and 28 volt systems can be used without special configuration or dropper resistors (we recommend that any dropper resistor fitted for a previous transponder should always be removed). The TT31 is compatible with both parallel and serial altitude encoders; it can even act as a serial altitude repeater to provide a convenient altitude source for your GPS.

  • Retrofit – ‘plug and play’ installation for KT6A/C and KT78A transponders
  • Certified Mode S and 1090ES ADS-B Out capable
  • ADS-B STC available - compatible with various navigators including Garmin 400W and 500W series
  • Lowest power consumption in class
  • 240 watts nominal output
  • Great functionality and performance
  • TIS traffic capabilities
  • Backlit LCD display
  • No cavity tube – no warm up time required
  • No need for dropper resistors
  • Certified to FAA TSO C166b as a 2020 ‘mandate ready’ solution
  • Unbeatable value and quality - designed and manufactured in the U.K.
  • Two year worldwide warranty

  • Type: Class 1 Mode S Level 2 els
  • Certification: ETSO C166A, 2C112B and TSO C112, C166b
  • Compliance: ED-73B, DO-160E, DO-178B Level B, DO181C, DO-260B Class B1S, DO-254 Level C
  • Supply Voltage (DC): 11 – 33 V
  • Typical Current Consumption (at 14V): Idle: 0.22 A, Active: 0.45 A
  • Nominal Transmitter Power: 240 W at connector
  • Operating Temperature: -20°C to + 70°C
  • Cooling Requirement: No fan required
  • Weight: 1.35 kg
  • Dimensions (in tray): 40 x 160 x 239 mm (H x W x L)

  • TT31 unit and tray
  • Install kit
  • Installation and user manuals (in English, German and French)

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Prop 65 Warning: This product may contain chemicals known to the State of California to cause cancer, and birth defects or other reproductive harm.