Garmin GTX 330 and GTX 33 Transponders receive FAA certification

Jan. 15, 2009
OLATHE, Kan., 15 Jan. 2009. Officials at Garmin International announced that the company's GTX 330 and GTX 33 transponders received the FAA's Technical Standard Orders (TSO)-C166a authorization

OLATHE, Kan., 15 Jan. 2009. Officials at Garmin International announced that the company's GTX 330 and GTX 33 transponders received the Federal Aviation Administration's (FAA's) Technical Standard Orders (TSO)-C166a authorization.

The transponder, which has 1090 MHz Extended Squitter (ES) transmission capabilities, will establish aircraft on the path towards complying with the FAA's proposed requirement for ADS-B equipment.

"Pilots are starting to ask what Extended Squitter technology is and why it's important. ES is the cornerstone of the FAA's next generation airspace system and it provides precise information about the aircraft's location to air traffic control and other ADS-B equipped aircraft in the vicinity," says Gary Kelley, Garmin's vice president of marketing.

The FAA is beginning to implement a nationwide ADS-B infrastructure of ground stations to improve traffic efficiency and improve situational awareness in the cockpit. The FAA announced a dual link decision using the 1090 MHz ES and UAT mediums for ADS-B, and has proposed a mandate that all aircraft have ADS-B Out capabilities by January 1, 2020, Garmin officials say. The addition of 1090 MHz ES transmission capabilities to Garmin's Mode S transponders allows general aviation aircraft to meet the FAA's proposed requirements because the ES transmissions will automatically provide position, velocity, and heading information.

This frequent and highly accurate aircraft state information is intended to provide superior surveillance capability for air traffic control, which is presently dependent upon aircraft position information derived from ground radar interrogation that has a slower update rate. The 1090 MHz ES builds upon the existing transponder system by transmitting pertinent aircraft information independent of being interrogated.

This transponder TSO also includes an antenna diversity option, GTX 330D, that adds antenna diversity to the features of the GTX 330 for improved air-to-air surveillance of TCAS-equipped aircraft flying above the GTX 330D-equipped aircraft. Under the FAA's current Notice of Proposed Rulemaking for NextGen airspace published in 2007, (Docket No. FAA-2007-29305; Notice No. 07-15), the GTX 330D meets the FAA requirements for Automatic Dependent Surveillance-Broadcast (ADS-B) equipped aircraft, Garmin officials say.

The 1090 MHz ES upgrade preserves all of the existing GTX 330 and GTX 33 features. This includes Mode S TIS-A datalink reception and traffic, which are displayed on the GNS 430W, GNS 530W, and GMX 200 displays.

Garmin will offer the ES technology as a retrofit upgrade option for GTX 330 and GTX 33's already in the field, as well as an optional upgrade on newly purchased GTX 330 and GTX 33 transponders. Customers seeking an ES or ES diversity upgrade to their GTX 330 or GTX 33, or a new GTX 330, GTX 33, GTX 330D, and GTX 33D with the ES transmission capabilities should visit a Garmin dealer. For additional information, visit

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