As our refreshed ADS-B buyer’s guide on page 7 proves, there is no shortage of ADS-B In and Out solutions. But, what has been missing is a certified WAAS-equipped ADS-B system packaged in a rack-mounted transponder that works with OEM glass panels, retrofit displays, portable GPS and tablet computers. That’s a void Garmin plans to fill with its next-generation wireless ADS-B transponders—the GTX335 and GTX345.
Several years ago when it was looking like FAA-mandated ADS-B equipage was a sure thing, buyers logically envisioned an easy path to compliance with a transponder. That came early on with Garmin’s upgradable GTX330. But it was only a partial solution. It outputted ADS-B, but couldn’t receive the free FIS-B weather everyone wants. It also required a pricey WAAS GPS input (which meant a $10,000-plus GNS navigator upgrade) to complete the ADS-B output data. That didn’t help owners of lesser, non-WAAS-equipped aircraft. Let’s have a look at Garmin’s latest GTX.
The new transponders are based on a design Garmin has been using for years, beginning with the Mode A/C digital GTX327 transponder. If you have the GTX327 or the later GTX330, you’ll be hard-pressed to tell any difference between them and the new GTX335/GTX345 models. The new ones retain a flight timer and pressure altitude readout.
Garmin offers the new ADS-B transponder in several versions; the most basic is the entry-level GTX335 ES without GPS. At $2995, it has 1090ES extended squitter ADS-B Out, but no ADS-B In. If you think this entry-level model sounds a lot like Garmin’s previous GTX330ES, you are correct. Garmin says there is little if any significant difference between the two, other than the GTX335 having a lower price—nearly $1000 less.
While the GTX330ES will be replaced by the GTX335, Garmin made it clear that it can support the GTX330ES series for years to come. That makes sense, since the new models are based on the existing GTX330-series platform.
The GTX335 is available with internal WAAS GPS as an option, which meets the ADS-B mandate standard for a position source and increases the price to $3795. This means you won’t have to install a panel-mounted GPS to drive the transponder. The shop will have to install a GPS antenna, of course, and the transponder will need a traditional L-band antenna system like any transponder.
The $4995 GTX345 series kicks the interface potential up to a higher level with a dual-band ADS-B In receiver. Dual bands mean the transponder can receive ADS-B data on both 978 and 1090 MHz frequencies. Like the GTX335, the GTX345 is a 1090ES unit, making it a player for higher altitudes where 1090ES is required. The flagship GTX345 with internal WAAS GPS is $5795.
A major difference between the GTX345 and lower-end GTX335 is the internal wireless Bluetooth transceiver, which follows the footsteps of Garmin’s remote-mounted Flight Stream wireless hub. Using Garmin’s Connext Bluetooth link, the GTX345 streams ADS-B traffic and FIS-B weather data to the aera795/796 portable GPS, iOS and Android tablets running the Garmin Pilot navigation app, in addition to the ForeFlight Mobile app for iPad.
The data interface trickles down from the Flight Stream two-way data transfer protocol (it’s only a one-way communication stream between the transponder and tablet app) and it enables the transfer of pressure altitude data, ADS-B messaging, plus FIS-B weather and ADS-B traffic overlay. You’ll need to have ForeFlight Mobile version 7.20 or higher for the interface to work, while the ADS-B In data interface isn’t limited to portable equipment.
Through a wired interface, the GTX345 sends both ADS-B weather and traffic to the GTN750 and GTN650 navigators, and to the GNS530W and GNS430W WAAS navigators.
As with the older GTX33-series remote transponder, the GTX345 is available in a remote LRU version, the GTX345-R. This enables the GTN750 to display and provide tuning of transponder squawk codes and mode functions, eliminating the need for a panel control head.
But don’t expect the same functionality with all displays. For example, the GTN750 and GTN650 can display up to 60 ADS-B airborne and ground traffic targets in true ADS-B symbology. As for FIS-B weather, the GTN750 will display regional and CONUS NEXRAD, METARs, TAFs, PIREPs, winds and temperature aloft, AIRMETs, SIGMETs, TFRs and NOTAMs. That’s pretty much a full-boat ADS-B interface. There is also Garmin’s TargetTrend function—advanced traffic awareness that portrays the traffic on-screen in real and future time.
The GNS530W and GNS430W interface is somewhat limited. For example, these displays will only support eight airborne traffic targets displayed in TIS-A symbology. As for FIS-B weather, you’ll see regional and CONUS NEXRAD, METARs and TAFs. Additionally, you won’t be able to control the remote GTX345-R.
The GTX345 will also work with Garmin’s stand-alone GMX200 MFD, displaying up to 60 traffic targets, plus regional NEXRAD, TAFs and METARs. It will also work with the long- discontinued MX20, but out experience is the unit just doesn’t have the processing horsepower to deal with weather graphics—potentially shutting down or freezing up when you need it the most.
Garmin says an interface with the G600/G500 PFD is planned for a future release, displaying all of the traffic and weather products that the GTN navigators are capable of.
ADS-B In capability has been a nagging shortcoming of Garmin’s G1000 integrated avionics suite, and the GTX345 finally enables the capability. The GTX345-R can take the place of the existing remote GTX transponder in select G1000 systems.
For most G1000s, the $5795 GTX345-R with internal GPS is used—requiring another antenna. It would be easier to use the existing G1000 WAAS LRU to drive the transponder, but it requires OEM approval. The GTX345-R can display FIS-B weather and ADS-B traffic on some G1000 systems, including non-WAAS suites in Cessna 172, 182, 206, 208 Caravan and 350/400 Corvalis singles. It’s also fully compatible with G1000-equipped Piper models, including the Meridian turboprop.
Display of GTX345-R ADS-B traffic on any G1000 requires GDU software version 7.10 and GIA63 version 5.31 or later. For FIS-B weather display, any G1000 suite requires GDU software version 12.00 and GIA63 version 6.20 or later. Check with your G1000 service center on upgrade costs and OEM approval status of the software. Some aren’t approved yet, including the Diamond DA40NG and DA42. The Hawker Beechcraft G58, G36 and some G1000 Mooney models aren’t approved, either.
Competition, New Altitude Encoder
Garmin isn’t alone with a transponder-based total ADS-B solution. Appareo is working on its Stratux ESG GPS-equipped model, but the new GTX series is certified and available now. Another model that’s in the works is the $3500 Sandia Aerospace STX360 Sentinel. Sandia says it will be available in a remote LRU for interfacing with EFIS displays.
Unlike the Garmin and Appareo 1090ES solutions, it won’t be a player in high-flying aircraft since it outputs ADS-B on 978 MHz. While it also receives ADS-B In on 978 MHz, it won’t display NEXRAD graphics on its LCD display (only METARs) and it doesn’t have an internal WAAS GPS receiver. It does have a wireless transceiver for outputting FIS-B and ADS-B traffic to a tablet, but Sandia hasn’t announced app compatibility. Sandia says it’s on track for certification later this year.
In our estimation, that leaves L-3 Aviation, with its Lynx NGT9000 multi-function transponder, the closest certified competitor to the GTX345. We covered the NGT9000—which starts at $6800—in the April 2015 issue of Aviation Consumer and liked its scalability, bright RGB touch display and intuitive feature set. It doesn’t have an internal wireless transceiver, so you’ll have to purchase an optional module to stream the data to tablets running the WingX Pro navigation app. The flagship NGT9000D+, which has diversity, internal WAAS GPS, plus an internal TAS traffic processor, has an eye-popping price tag of nearly $12,000.
Garmin has also introduced its next-generation Mode C altitude encoder, simply called the Garmin Altitude Encoder. At $279, it’s the smallest digitizer we’ve seen to date and cuts down on installation effort because it mounts directly to the GTX345/335 mounting tray. Garmin says the encoder has a proprietary data code that works directly with the GTX335/345 transponders. You still need Mode C altitude encoding in a full-up ADS-B interface.
While manufacturers like Sandia Aerospace (which previously supplied Garmin with its SAE-series digitizer) have conveniently integrated the encoder into the transponder, there is a downside: The static system has to be recertified if the transponder is removed and reinstalled.
No doubt, buyers who recently invested in Garmin’s GDL88 remote ADS-B solution are shaking heads at Garmin’s new transponder technology, which promises an easier, cheaper and cleaner installation. But, that’s the cost of early adoption in a rapidly changing ADS-B market.
Mandate-Compliant Panel ADS-B Products
|Appareo Stratus ESG||1090ES ADS-B Transponder||N/A||$3490||Has internal WAAS GPS, interfaces with Stratus portable|
|Aspen Avionics ATX100||978 UAT out, 978 UAT in||Evolution MFD||$2645||Requires external GPS|
|Aspen Avionics ATX100G||978 UAT out, 978 UAT in||Evolution MFD||$3495||Has internal WAAS GPS, ADS-B In and Out|
|Avidyne AXP340||1090ES ADS-B Transponder||N/A||$3995||Partial plug-and-play with some existing BendixKing KT76A/C, KT78A transponders, requires WAAS GPS input|
|Avidyne MLB100||978 UAT in||IFD540/IFD440||$2495||Compatible with Avidyne’s IFD540 navigator|
|BendixKing KT74||1090ES ADS-B Transponder||N/A||$2999||Partial plug-and-play with KT76A/C, KT78A transponders, requires WAAS GPS input|
|BendixKing KGX130||978 UAT in||iOS TABLET|
MFD traffic only
|$1489||ADS-B In only, for use with 1090ES transponder|
|BendixKing KGX150||978 UAT out, 978 UAT in||iOS TABLET|
MFD traffic only
|$4069||Has internal WAAS GPS|
|BendixKing KGX150||978 UAT out, 978 UAT in||iOS TABLET|
MFD traffic only
|$3489||Version without internal WAAS GPS|
|Freeflight Systems FDL-978-TX||978 UAT out||N/A||$2995||Has Diversity, includes control head|
|Freeflight Systems FDL-978-XVR||978 UAT out, 978 UAT in||iOS, Android|
|$3695||Has Diversity, includes control head and WiFi module|
|Freeflight Systems FDL-978-XVR||978 UAT out, 978 UAT in||iOS tablet |
|$4495||Internal WAAS GPS, includes WiFi module for tablet use|
|Freeflight Systems FDL-978-TX/L||978 UAT out||N/A||$1995||Lite version, no ARINC card, upgradeable to ADS-B In|
|Freeflight Systems FDL-1090-TX||1090ES ADS-B Transponder||N/A||$4495||Remote control head/processor design, requires |
WAAS GPS input
|Garmin GTX335||1090ES ADS-B Transponder||N/A||$3295||Internal WAAS $3795|
|Garmin GTX345||1090ES ADS-B Transponder||GTN/GNS/G1000/TAB||$4995||Internal WAAS $5795, GTX345-R LRU priced the same|
|Garmin GDL84||978 UAT out, dual-band in||iOS, Android |
|$3995||Standalone ADS-B Out and In, wireless Bluetooth connectivity with Flight Stream 110/210. Requires Garmin Pilot, ForeFlight tablet app. *$4495 with Flight Stream 210 (built-in AHRS)|
|Garmin GDL88||978 UAT out, dual-band in||GNS530W/430W|
|$3995||Requires WAAS GPS input, tablet interface requires Flight Stream wireless Bluetooth module, Garmin Pilot or ForeFlight app|
|Garmin GDL88-W||978 UAT, dual-band in||GNS530W/430W|
|$5143||Has built-in WAAS GPS receiver, tablet tablet interface requires Flight Stream wireless Bluetooth, Garmin Pilot or ForeFlight app|
|Garmin GDL88-D||978 UAT, dual-band in||GNS530W/430W|
|$4495||Diversity model (requires top and bottom antenna installation), requires WAAS GPS input, tablet interface requires Flight Stream wireless Bluetooth module, ForeFlight or Garmin Pilot app|
|Garmin GDL88-WD||978 UAT, dual-band in||GNS530W/430W|
|$5643||Has built-in WAAS GPS receiver, Diversity (requires top and bottom antenna installation), tablet tablet interface requires Flight Stream wireless Bluetooth module, ForeFlight or Garmin Pilot app|
|L-3 Aviation Lynx NGT-9000D+||1090ES ADS-B transponder|
duAL-band ads-B in
|Self-contained, Garmin MX20||$11,933||Rack-mounted, internal WAAS, TAS, Diversity, displays traffic on any display that accepts Skywatch data|
|L-3 Aviation Lynx NGT-9000D||1090ES ADS-B transponder|
duAL-band ads-B in
|Self-contained, Garmin MX20||$8133||Has Diversity, but no internal TAS|
|L-3 Aviation Lynx NGT-9000+||1090ES ADS-B transponder|
duAL-band ads-B in
|Self-contained, Garmin MX20||$9200||Has internal TAS, but no Diversity|
|L-3 Aviation Lynx NGT-9000||1090ES ADS-B transponder|
duAL-band ads-B in
|Self-contained, Garmin MX20||$6800||No Diversity, no internal TAS|
|L-3 Aviation Lynx NGT-2500||978 UAT out, 978 UAT in||MX20, tablet||$3467||iOS, Android tablet interface requires $270 optional WiFi module, $1223 control panel may be required|
|L-3 Aviation Lynx NGT-2000||978 UAT out, 978 UAT in||Tablet||$3200||Requires $270 WiFi module, built-in WAAS GPS, could require $1223 optional control panel|
|L-3 Aviation Lynx NGT-1000||978 UAT out||N/A||$2132||Basic mandate-compliance, built-in WAAS GPS, could |
require control panel installation
|NavWorx ADS600||978 UAT in||Garmin MX20, GMX200 *GNS430/530/G500/600||$1199||*Garmin display interface will overlay traffic only. $2399 version with internal GPS can interface to 1090ES transponders|
|NavWorx ADS600-B||978 UAT in, 978 UAT out||Garmin MX20, GMX200 *GNS430/530/G500/600||$2399||Has non-certified built-in WAAS GPS for aircraft that don’t need to comply with ADS-B mandate|
|NavWorx ADS600-BG||978 UAT in, 978 UAT out||Garmin MX20, GMX200 *GNS430/530/G500/600||$3499||Built-in mandate-compliant WAAS GPS, complete with antennas and installation hardware|
|Sandia Aerospace STX360||978 UAT in, 978 UAT out||Internal||TBD||Mode A/C transponder with integral ADS-B In/Out|
|Trig Avionics TT31||1090ES Transponder||N/A||$2568||Requires external WAAS GPS input, KT76A/C replacement|
|Trig Avionics TT22||1090ES Transponder||N/A||$2595||Remote control head and processor|
Non-Certified Portable ADS-B Products
|PRODUCT||PRICE||SIZE||SPECS||BATTERY LIFE||MAJOR APPS SUPPORTED||COMMENTS|
|Dual XGPS170||$549||4.3 x 2.7 x 0.8||978 mHz||5 hours||WingX Pro, fltplan.com, Seattle Avionics FLYQ, Adventure Pilot IFLY||Convenient chassis design with nonskid base|
|$1150||2.5 x 2.5 x 1.5||978 mHz|
|6-8 hours||WingX, Adventure Pilot IFLY, Global Nav Source, iPad EFB, SkyVision Extreme||ADS-B only; no AHRS, dual band|
|$1400||2.5 x 2.5 x 1.5||978 mHz|
|6-8 hours||WingX, Adventure Pilot IFLY, Global Nav Source, iPad EFB, SkyVision Extreme||Top overall performer for GPS, ADS-B and EFIS; smallest physical size; runs HOT|
|iLevil AW||$1395||4 x 2.5 x 1||978 mHz||5 hours||WingX, FLYQ, Adventure Pilot, AHRS Utility, Xavion, AvNav EFB, Avare||Can be be hardwired, pressure transducer interface for airspeed/altitude|
|iLevil 2SW||$1195||4 x 2.5 x 1||978 mHz||5 hours||WingX, FLYQ, Adventure Pilot IFLY, AHRS Utility, Xavion, AvNav EFB, Avare||good performer, solar charging, now has dual frequency ADS-B|
|Stratus II||$899||6 x 2.6 x 1.25||978 mHz|
|8 hours||Foreflight only||Good overall value; runs coolest; requires toggling to separate app to use EFIS|
|Stratus I||$499||5.75 x 4.25 x 1||978 mHz||8 hours||Foreflight only||First-generation model, no AHRS, single-band receiver|
|$599, $699 w/ battery||3.5 x 1.9 x 6||978 mHz|
|4 hours||Garmin Pilot for iOS and Android, Garmin GPS396/496/696/AERA500 via cable, Garmin 796||Bulky footprint, especially with optional battery installed|
|Garmin GDL39 3D||$849,|
$899 w/ battery
|3.5 x 1.9 x 6||978 mHz|
|4 hours||Garmin Pilot for iOS and Android, Garmin GPS396/496/696/AERA500 via cable, Garmin 796||Has AHRS output for driving Garmin Pilot attitude and synthetic vision display|
|SkyVision SALUS-3 978UAT/1090ES||$1099||8 x 3 x 2||978 mHz|
|external voltage||Xtreme Vision, WingX Pro, SkyRadar, Adventure |
|First portable solution attempting to meet ADS-B mandate certification|
|Stratux||$100+||varies with case option||978 mHz|
|external voltage||Foreflight, WingX, FLYQ||Assemble your own receiver and play the ADS-B data on a variety of apps|