A panel-mounted Mode S digital transponder series with traffic datalink capability and dedicated pushbutton keys for squawk code selection, the GTX 330 family brings ATC aircraft surveillance to new levels of precision, reliability and performance.

Leading the way with ADS-B

With IFR-certified ES, or Extended Squitter, versions of the GTX 330, Garmin has taken the lead in providing an affordable pathway to ADS-B compliance for the FAA’s proposed Next Generation airspace system. Using precise GPS-referenced positioning information, the extended squitter technology enables transponders to automatically transmit more accurate, and more useful, traffic surveillance data – including aircraft flight ID, position, altitude, velocity, climb/descent, and heading information. (Compared to traditional Mode S and Mode C transponders, which can only broadcast altitude, and thus require ground-based radar to correlate and identify the aircraft’s position.)

Traffic in simulcast

As the first general aviation transponder to receive TSO-C166a authorization for 1090 MHz extended squitter transmission, Garmin’s GTX 330 ES improves upon the existing transponder query system – while working seamlessly with existing ATC protocols. The ADS-B reports provide ground controllers with considerably faster updates than traditional radar. And by simultaneously broadcasting this information to TAS or TCAS equipped pilots, it enables them to essentially see the same traffic picture for their location that ATC is watching on the ground. Thus, with everyone in the ADS-B loop watching and reacting to the same flight trajectories, safe separation is far easier to maintain.

The quality shows

All the features of Garmin’s standard GTX 330 transponder are retained in the ES version: Solid-state design, 250-watt transmitter, remote ident and auto standby, altitude monitor with voice alerts, TIS traffic interface, and an easy-to-read LCD display that reverses its numbers out of black for optimal viewing in all lighting conditions. A dedicated VFR squawk code button makes entering the numbers quick and easy. And a variety of useful timing and display functions include flight time, count-up and count-down timers, plus current pressure altitude. The GTX 330 can also be used to satisfy the European mandate for Mode S level 2 surveillance. And an antenna diversity option is added with the GTX 330D – for improved air-to-air surveillance of TCAS-equipped aircraft flying above you.

Note: The FAA is expected to finalize requirements for ADS-B mandated compliance in mid May 2010. Until these regulations are published, it is unknown if the GTX 330 ES will meet the mandatory requirements for compliance in 2020.