TT31 Mode S transponder now has 1090MHz Extended Squitter ADS-B out capability

Trig Avionics Limited, of Edinburgh, Scotland, has released a new version of their popular TT31 Mode S transponder that includes support for ADS-B output. Next generation air traffic management systems in Europe, the USA and Australia will all use ADS-B as part of their surveillance strategy. “We think it is important that our customers have the confidence that their investment in our products is future proof”, said Andy Davis, Trig Chief Executive. “The migration from ground based radar to ADS-B technology has been widely publicised, and anyone buying a transponder today needs to know that it will support the future requirements as well as current Mode S mandates.”

The TT31 implements a key part of this system by providing the 1090MHz Extended Squitter datalink. The new ADS-B capability is standard on all new TT31 transponders from now, and is available as an upgrade to all existing TT31 customers.

By connecting an existing GPS to a Trig Mode S transponder, aircraft position and track information is broadcast on the transponder data link. As well as being visible to ATC these transmissions can be used by aircraft collision avoidance systems and simple ground receivers. These receivers are inexpensive and can provide awareness of traffic position at uncontrolled airports, and can even be used to monitor a student solo exercise.

EASA has proposed two new regulatory steps for 2008 – the European technical standard for ADS-B position reporting equipment, ETSO C166a, and a new airworthiness standard for ADS-B installations, AMC20-24. “The new Trig transponder software implements all the technical features of these new requirements, and Trig expect to have one of the first approvals under ETSO C166a”, said Martin Gray, Trig Engineering Manager.

The TT31 transponder is compatible with many existing Mode A/C transponder installations and represents a cost effective way of meeting current Mode S requirements whilst also preparing for the planned future ADS-B environment.