The TT31 is a power-efficient, inexpensive, Mode S transponder that meets the European elementary surveillance requirements. The TT31 fits in the same mounting tray as the KT76A transponder, making it a great choice for either upgrades or new installations.

The TT31 is TSO approved for fitting to European and FAA registered aircraft. With a new software upgrade and a connection to an appropriate GPS, this will make the TT31 compliant with the FAA final rule on ADS-B Out for 2020.

All Mode S transponder upgrades for EASA certified aircraft must be carried out by a licensed engineer using a Minor Change approved by EASA. The TT31 plug and play design minimises the cost and downtime for the upgrade, and our library of pre-approved Minor Changes for popular aircraft types means that for many customers there are no EASA fees to pay either! Contact your avionics dealer for more information.