• Skip to primary navigation
  • Skip to main content
General Aviation News

General Aviation News

Because flying is cool

  • Pictures of the Day
    • Submit Picture of the Day
  • Stories
    • News
    • Features
    • Opinion
    • Products
    • NTSB Accidents
    • ASRS Reports
  • Comments
  • Classifieds
    • Place Classified Ad
  • Events
  • Digital Archives
  • Subscribe
  • Show Search
Hide Search

Garmin introduces ADS-B transponders that feature two antennas

By General Aviation News Staff · March 25, 2019 ·

On opening day of the Aircraft Electronic Association convention, Garmin introduced the GTX 335D and GTX 345D, two diversity transponders that provide Automatic Dependent Surveillance-Broadcast (ADS-B) Out coverage.

The GTX 335D offers ADS-B Out, while the GTX 345D provides ADS-B Out, as well as ADS-B In traffic and weather for display on compatible avionics and mobile devices. Remote-mount versions are also available.

The GTX 335D/GTX 345D are intended for qualifying aircraft that may prefer or require a “diversity solution,” while also meeting or exceeding global ADS-B airspace requirements, according to Garmin officials.

The GTX 335D/GTX 345D utilize two antennas mounted on the top and bottom of the aircraft, providing “superior operational coverage,” Garmin officials said in a prepared release.

The Garmin GTX 345

As opposed to having a single antenna that is mounted on the bottom of the aircraft, diversity antennas help reduce antenna “shading” caused when the aircraft turns or maneuvers. Diversity antennas also improve line-of-sight visibility and allow the transponder to send and receive ADS-B transmissions from other participating aircraft, further improving visibility while operating throughout the global airspace system, company officials explain.

Select G1000, G1000 NXi and G3000-equipped aircraft have a simple path to incorporate a diversity transponder-based ADS-B solution using the GTX 335D/GTX 345D, Garmin officials note. A remote-mounted version of the GTX 335D or GTX 345D takes the place of the aircraft’s transponder and interfaces with the aircraft’s existing WAAS position source to meet ADS-B Out requirements. The GTX 345D is capable of displaying various ADS-B In benefits, including subscription free Flight Information Service-Broadcast (FIS-B) weather and ADS-B traffic on the primary flight display (PFD) and multi-function display (MFD).

In addition to integrated flight deck compatibility, the GTX 335D/GTX 345D interface with a variety of other Garmin avionics, flight displays, and mobile devices, including the GTN 650/750 and GNS 430W/530W navigators, the G500 TXi/G600 TXi/G700 TXi and G500/G600 flight displays, as well as the aera 796/795 and aera 660 portables.

These transponders are also compatible with the Garmin Pilot, FltPlan Go, and ForeFlight Mobile applications, as well as other third-party avionics.

The GTX 345D unlocks many capabilities for pilots by displaying ADS-B traffic and FIS-B weather on compatible products in the cockpit. Exclusive features such as TargetTrend and TerminalTraffic enhance the display of traffic in Garmin products.

The GTX 345D also includes a dual-link ADS-B receiver that provides pilots with a complete picture of ADS-B equipped traffic. The GTX 345D may be integrated into the aircraft’s audio panel to provide ATC-like audible alerts, such as “Traffic: 10 O’Clock, same altitude, two miles” to help pilots keep their eyes outside the cockpit when looking for traffic.

FIS-B weather products include NEXRAD, METARs, TAFs, PIREPs, winds and temperatures aloft, NOTAMs, AIRMETs and SIGMETs. New FIS-B weather products, including lightning, turbulence, icing (current and forecast) and cloud tops are currently capable of displaying on Garmin Pilot and the aera 660. Additional Garmin display compatibility with these new FIS-B weather products is expected later this year, company officials report.

The GTX 335D and GTX 345D ADS-B transponders have received Technical Standard Order (TSO) authorization from the FAA and deliveries for select installations will begin in April 2019.

Garmin will have an updated Aircraft Model List (AML) Supplemental Type Certificate (STC) in the late second quarter of 2019 comprising of hundreds of aircraft makes and models.

The GTX 335D is priced at $6,495, while the GTX 345D is $7,995.

Reader Interactions

Share this story

  • Share on Twitter Share on Twitter
  • Share on Facebook Share on Facebook
  • Share on LinkedIn Share on LinkedIn
  • Share on Reddit Share on Reddit
  • Share via Email Share via Email

Join 110,000 readers each month and get the latest news and entertainment from the world of general aviation direct to your inbox, daily. Sign up here.

Curious to know what fellow pilots think on random stories on the General Aviation News website? Click on our Recent Comments page to find out. Read our Comment Policy here.

Comments

  1. charles tanner says

    March 28, 2019 at 3:13 pm

    keep me posted on the gtx 335D & 345D’s, please for my Colt airplane. charles

  2. Larry says

    March 26, 2019 at 6:59 am

    Mark my words, folks. Once Jan 1, 2020 comes and goes the FAA beancounters will begin eyeing the cost of maintaining the ~650 ADS-B ground stations. At some point, they’ll figure out they can do the same task with just a few satellites. At that point, they’ll pile still another “mandate” upon aircraft owners … that of diversity transponders. Satellites won’t be able to reliably see non-diversity systems so they’ll then require diversity systems. Put it on your calendar for about 10 years from now. Kinda like mandating 406 ELT’s because satellites do the job better and cheaper … for everyone but the aircraft owner.

© 2025 Flyer Media, Inc. All rights reserved. Privacy Policy.

  • About
  • Advertise
  • Comment Policy
  • Contact Us
  • Privacy Policy
  • Writer’s Guidelines
  • Photographer’s Guidelines