Technique: Experimental avionics show the way

The news came with little fanfare on the third day of the Sun ’n Fun International Fly-In and Expo in Lakeland, Florida, and it was stunning. Dynon’s D-10A, a non-TSO electronic flight instrument system popular in Experimental and Light Sport aircraft, has been approved as a replacement to the primary attitude indicator in the Experimental Aircraft Association’s flying club Cessna 172 via a supplemental type certificate (STC). The STC, a joint project between EAA and Dynon, will be available through EAA, although the association has not yet released details or pricing information.

By granting that single STC, however, the FAA has created a precedent that will allow other avionics firms to bring their own extremely capable, proven, relatively inexpensive, safety-enhancing avionics to Standard-category aircraft for the first time. Until now, non-TSO avionics had been strictly limited to Experimental and Light Sport aircraft.

“This is one of the biggest breakthroughs we’ve had in a long time,” EAA President Jack Pelton said with characteristic understatement. “This is the bridge that will allow other innovative, safety-enhancing products into the existing aircraft fleet.”

The move brings the benefits of Experimental avionics—perhaps aviation’s most competitive, dynamic, and technically innovative niche—to the relative backwater of Standard-category aircraft where the staggering cost and slow pace of developing new products has meant little progress.

The significance of the EAA/Dynon STC extends far beyond attitude indicators. It has the potential to bring newer, more reliable autopilots, engine monitors, fuel gauges, and even ADS-B traffic and weather systems to Standard category aircraft thereby reducing prices. Dynon officials said their company is pursuing similar STCs across its entire product line, up to and including its integrated SkyView electronics suite, a single- or multi-screen system that can include redundant air data computers, a digital autopilot, GPS-derived synthetic vision, and weather, traffic, and terrain warnings. The SkyView system typically sells for about $10,000—less than half the cost of similar TSO equipment.

Dynon avionics are installed in 15,000 Experimental and Light Sport aircraft, of which there are roughly 35,000 in the United States. The new STC gives the Washington-based firm access to a far larger market of about 140,000 active piston aircraft in the United States.

The move also is sure to spur other Experimental avionics manufacturers to pursue their own STCs and broaden them far beyond the Cessna 150/152, 172, Piper PA–28, and PA–38 that the FAA has approved so far.

Advanced, GRT Avionics, and MGL are a few of the firms that are dedicated to the Experimental market, and industry leader Garmin makes both FAA-certified and Experimental products. For a small firm like GRT, the decision to seek a broader market for its existing engine monitors and primary flight displays is automatic.

“This is obviously great news for us and we’ll be on it right away,” said Todd Stehouwer, a principal at the Michigan-based company. “We’ve got products that GA pilots want but they can’t have unless they fly Experimental or Light Sport airplanes.”

For Garmin, the move puts new emphasis on its Experimental product line, which includes the integrated G3X avionics suite and the new G5, an all-in-one attitude instrument that can be used as a primary or backup display. Garmin’s “Team X” developers use the company’s extensive product line to produce new products ranging from audio panels to autopilots for the Experimental market.

Freed from the restrictive and time-consuming process of obtaining technical standard order approval, manufacturers of Experimental avionics can innovate and improve their products; because the cost of certifying isn’t passed on to the consumer, aircraft owners can afford to equip with newer, more capable systems. For pilots, flying with the new generation of Experimental avionics is typically far simpler than TSO products.

For example, Garmin’s FAA-approved G1000 avionics suite is a tremendously capable system that has multiple menus, sub-menus, buttons, knobs, and soft keys that can be used in a dizzying variety of combinations to accomplish many tasks. By contrast, the company’s Experimental G3X has familiar icons, a far shallower menu structure, and a touchscreen display that is much more intuitive to use.

The G3X owner’s manual is 328 pages. That’s a lot, but it’s nearly 300 pages fewer than Garmin’s G1000 manual.

I flew a G3X-equipped Carbon Cub on an extended trip through the Idaho backcountry and regarded the colorful box with the integrated autopilot as technological overkill. But it vastly enhanced the experience of flying in that rugged and remote part of the country by providing the seeming super power of always knowing what’s around the next bend, wind strength and direction, and whether a particular climb rate is sufficient to clear the next ridge.

Similarly, Dynon has gone to a great deal of effort to make its SkyView system simple to operate. It has a touch-screen option and two knobs and a single row of clearly marked buttons that control everything from the aircraft checklist to the transponder, autopilot, and moving map. Whether you’re flying VFR or IFR, you can’t help but be impressed with the thoughtful, orderly way it presents pilots with critical navigation, weather, and performance information and updates it in flight.

My introduction to the SkyView came on a transcontinental winter journey with powerful winds aloft, and the integrated autopilot kept the Van’s Aircraft RV–7A on an arrow-straight course, managed climbs and descents beautifully, and never clicked off in turbulence.

These and other Experimental avionics manufacturers design and build mature systems that are proven and refined. While no instrument is infallible, all of these modern devices provide better information and greater reliability than the vacuum systems they replace.

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Dynon avionics are in 15,000 Experimental and Light Sport aircraft.

Certification versus safety

Like many others, my airplane, a Van’s Aircraft RV–3, is equipped with both certified and noncertified avionics. Far from being an overlooked backup, the noncertified equipment makes flying in the clouds easy and safe.

While being vectored for a localizer approach to Runway 23 at Frederick, Maryland, I had the choice of following the monochromatic black dots on an FAA-certified KX-125 screen, or the magenta line on a GRT EFIS screen.

The GRT counted down the turn to final, and since it knows groundspeed and ground track, compensating for winds during rollout was automatic. Once the airplane symbol on the GPS screen was tracking the final approach course, a glance at the nav radio screen confirmed the localizer was centered. Nothing to it.

One could make a strong case that there’s nothing wrong with this situation since both the certified nav radio and non-TSO EFIS were being used for their intended purposes. The moving map on the EFIS enhances situational awareness, and the nav radio provides IFR course guidance. Everybody’s happy.

But what happens when information from the certified equipment and unapproved gear is at odds? What should you believe then? I tend to favor the unapproved gear.

While practicing GPS approaches using my IFR-approved but fairly ancient Garmin G300XL on a sunny day, I was dismayed by its inaccuracy. I had put the 15-year-old box in a demanding situation: a nearly 90-degree intercept of the final approach course six miles from the runway threshold. The old box did its best, but upon intercepting the final approach course, the map screen was achingly slow at redrawing the course line to follow to the runway. Once it did, the G300XL guidance was about 20 degrees off. The box recalibrated and provided an accurate course to steer at about three miles. But strictly following its indications would have resulted in a serpentine ground track and unstable approach. In actual IMC, the situation would have called for a missed approach.

Throughout all these machinations, however, a portable aera 660 was rock steady. It tracked the airplane’s movements with absolute fidelity and wasn’t thrown off by the steep intercept.

There’s nothing magical about FAA certification or IFR-approved avionics. The FAA’s new “performance-based” metrics for evaluating new equipment such as non-TSO avionics will make these proven technologies welcome additions to the panels of Standard aircraft.

Pilots, particularly IFR pilots, are taught to trust their instruments. But some are inherently more trustworthy than others—reliability and ease of use have little correlation to FAA certification.

My GRT EFIS and portable aera 660 are WAAS-enabled, GPS units that update their positions five times a second. In a pinch, I’ll rely on them over any IFR-approved but older non-WAAS navigator. In truth, I already do. —DMH