Garmin Mainstreams G3X Touch in Part 23 Airplanes

 - June 28, 2019, 10:07 AM

The benefits of the FAA’s new policy on approving lower-cost modern avionics for Part 23-certified airplanes become even more clear when flying an airplane with Garmin’s G3X Touch displays. 

The new policy sets some limits, including a 6,000-pound maximum takeoff weight and six seats or fewer, but it allows avionics that haven’t been certified to FAA technical standard order (TSO) standards to be installed in nearly 600 Class I airplane models, under an approved model list supplemental type certificate (AML-STC). This isn’t to say that the products can’t meet TSOs, just that they aren’t required to be certified to meet the TSOs. They still must undergo system-level testing, but, in fact, they are tested to basically the same hardware, environmental, and software standards as certified avionics—just without obtaining a TSO sticker.

“The net result is enhanced safety for the fleet [of older airplanes],” said Joe Gepner, manager of Garmin’s Team X, which designed the G3X avionics. These modern low-cost avionics give pilots far more situational awareness at an affordable price. “That was our pitch to the FAA, and they got behind it,” he said. 

Garmin director of aircraft certification Robert Murray further explained that the FAA understood the fundamental issue; few owners of older aircraft with low hull values are going to spend tens of thousands of dollars on TSO’d avionics, but the vacuum-driven instruments in these aircraft are a major weak point, safety-wise. For example, the failure sequence of vacuum-driven attitude indicators is that they slowly roll away from the proper attitude without displaying a failure flag. Detecting a failed vacuum pump is difficult, and vacuum pumps themselves have limited lifespans but give pilots no indication that failure is imminent. A modern, even non-TSO’d glass display is far more reliable than the vacuum system and mechanical instruments it replaces, and there is no safety downside to removing the vacuum system in favor of low-cost FAA-approved modern avionics from Garmin and other manufacturers such as Aspen Avionics, Dynon, and others. 

“That’s where the argument came from,” added Gepner. “The stuff [the FAA] won’t let [be installed] today is leaps and bounds better than the avionics from the 1970s. [Avionics] in experimental aircraft are so much better. The certified stuff doesn’t compare. Old analog components, when the spinning mass gyro fails and winds down, it can’t tell it’s failing. Now, there are so many fault warnings.

“Garmin has a unique advantage,” he continued. “We have all of this tech in-house, it goes all the way to Part 25 aircraft. If it’s software, there’s no reason we can’t reuse it. We can bring high-quality safety-enhancing features and support down into the GA market for less cost.”

Garmin manufactures attitude and heading reference systems (AHRS) for sophisticated Part 25 business jets, and for products like G3X Touch, it can run the exact same testing regimen without the burdensome documentation required by certification rules. “Products get tested and designed in the same way,” Gepner said, “and this helped make our argument to the FAA easier. We’re just missing a huge pile of paper. But it doesn’t matter what you’re flying, we want them to be safe.” 

Gepner pointed out another advantage of G3X Touch, and that is as a display for ADS-B In traffic and weather, which eliminates the need for a portable ADS-B In receiver with its extra wires for charging and a tablet to view the information. “This lets you have the option to see ADS-B In on avionics permanently installed on the aircraft,” he said. With ADS-B In, Garmin's TargetTrend and TerminalTraffic can be displayed on the G3X Touch. SiriusXM weather and audio is available, too, when using the Garmin GDL 51R/52R receivers. The Touch displays also can show VFR sectional and IFR en route charts as well as geo-referenced instrument approach charts. 

G3X Touch received FAA approval for installation under the AML-STC in March 2019. Plans call for adding more aircraft to the AML, basically most models in which at least a 7-inch G3X Touch display can fit in the panel. Composite airplanes will require additional testing to meet HIRF and lightning standards. Garmin is also working with EASA on European certification. The 10.6-inch display retails for $9,995 and the 7-inch display for $7,995. These prices include GPS antenna, installation kit, AHRS sensor, and magnetometer.

Flying with the G3X Touch

To demonstrate the improvements available with G3X Touch, Garmin installed a full panel of G3X Touch and other avionics in a Grumman Tiger. I traveled to Garmin’s Olathe, Kansas headquarters in late April to see what it was like to fly with G3X Touch, which was formerly available only for experimental-amateur-built aircraft. 

The Tiger’s panel is stuffed with Garmin products, and clearly this is going to be one happy owner. The focal point starts with two G3X Touch units, a 10.6-inch GDU 460 in landscape orientation and 7-inch GDU 470 in portrait mode. For navigation and com, there is a GTN 650 GPS/com/navigator and a GNC 225 navcom. A GFC 500 autopilot is installed, along with a G5 instrument providing backup attitude, a remote-mount transponder, and a GMA 345 audio panel. The G5 is what allows removal of the vacuum system. 

A difference between G3X Touch and more expensive TSO’d avionics is that it doesn’t offer interoperability with third-party radios and autopilots. “It doesn’t have analog input/output,” and this helps keep costs down, explained Gepner. G3X Touch also can’t display flight director bars from third-party autopilots. To get that third-party functionality and not have to replace existing non-Garmin radios and autopilot, a buyer would have to step up to the G500 TXi display. G3X Touch also doesn’t offer angle-of-attack display, but these features will likely be added in later software updates. 

Garmin’s engine indicating instruments (EIS) are optional for G3X Touch and were installed on the Tiger. The GTN provides the necessary navigation information, but Garmin’s new GPS 175 or GNX 375 navigators can also serve the same function. “It’s kind of neat how you can piece together what you want,” Murray said. 

During the demo flight (I was in the left seat so I could interact with the G3X Touch units, and Garmin media relations specialist Jessica Koss flew from the right side), I got a good feel for the utility and ease of use of the G3X and the GFC 500 autopilot. 

Compared to the typical analog instruments and basic navcoms that are usual in this type of airplane, the new panel is a remarkable improvement. The primary flight display (PFD) on the 10-inch TXi can be set to cover all of the screen, or split with the optional EIS in a strip on one side. The EIS can also be displayed on the 7-inch GDU 470 multifunction display (MFD). Synthetic vision enhances the PFD, as does the flight path marker symbol. Helpfully, traffic is shown on the PFD in the right perspective to help make spotting other aircraft easier. 

Changing the split screens on the displays is easy, just touch the mode button on the top left or right to select between “Split” or “Full” screen, or press and hold the back key on the display’s bevel. The larger GDU 460 includes an inset view, and touching the inset pulls up options to display various information, such as map zoom, traffic, flight plan, nearest airports, and g-meter reset. 

Old-school pilots might want to look at traditional instruments, so the GDU 460 can be set up with a “six-pack” display of round gages instead of linear tapes. There is a surprising amount of customization available in the G3X Touch displays, from selection of data fields to changing knob actions and where the EIS shows up. Below the HSI is a blue pointer that indicates the best diversion airport, and this can also be customized for criteria such as runway length, type, and whether it’s within gliding distance. 

The G3X Touch displays' customization features also include virtual keyboards in Qwerty or ABCDE format to audio alerts, airspace alarms, fuel timers and reminders, etc. 

In the setup in the Tiger, there are three AHRS sources (G5, and both G3Xs), and the GFC 500 autopilot automatically selects the best source. Even better, if either or both G3X units fail, the autopilot can be re-engaged using the G5 as the AHRS source, and it’s still possible to fly a fully coupled approach with the G5. The G5 and G3X Touches synchronize altimeter baro settings, so there’s no need to set each one separately.

We tried some maneuvers that engaged the GFC 500 autopilot’s Electronic Stability & Protection (ESP) system, something that is a real help for pilots flying single-pilot IFR in airplanes like the Tiger. When I banked above the roll limit for more than 10 seconds, which engages ESP, the system automatically returned the airplane to level flight. I tried that with the pitch limit and again after 10 seconds of ESP engagement, the airplane returned to straight-and-level. Next, I slowed down but maintained altitude, and as the Tiger neared stall speed, the autopilot lowered the nose to maintain at least five knots above stall. 

Returning to New Century Aircenter, I set up the visual approach to Runway 22 and Koss brought us in for a smooth landing in the gusty Kansas winds while I shot photos of the G3X displays. 

None of the many G3X Touch features are new for builders and flyers of experimental aircraft that have been flying with G3X Touch avionics for many years, but now the safety and operational benefits of these products are available for tens of thousands of certified airplanes.