Avionics: What’s the difference?

The glass panel revolution that’s transforming the general aviation fleet can trace its lineage to airlines and military jets—as well as a kitchen table in a rural home on the Tennessee/Georgia border.

Unlike previous avionics advancements that were driven by research and development laboratories at large corporations, many of the products that are having such a profound effect on GA were created or inspired by start-up firms that first placed their products in experimental aircraft.

But their innovations and refinements—such as GPS-based synthetic vision, terrain avoidance, and pictorial “highway in the sky” navigation—are being adopted by GA so quickly and thoroughly that it’s nearly impossible to find any new production aircraft, light sport and primary trainers included, with old-fashioned, electro-mechanical steam gauges.

Two years ago, the notion of glass cockpits for certified, single-engine piston aircraft was still a novelty. Now, a potent combination of start-up and long-established avionics firms are producing a dazzling series of glass panels for new aircraft and retrofits that slash demand for panel space, electrical current, and—in a few cases—dollars. In 2008, Aspen, Avidyne, Bendix/King, and Garmin introduced competing, all-in-one, glass-panel avionics for the piston GA market.

If the same trends that have played out in airline, military, corporate, and experimental cockpits hold true for GA, an instrument pilot’s hard-won ability to interpret a vacuum-driven six pack—or fly partial panel on needle, ball, and airspeed—may soon be reduced to an anachronistic parlor trick.

Moving technology forward

The technology that holds so much promise for GA goes back at least to 1997 when Greg Richter, founder of Blue Mountain Avionics, flew an experimental, one-off electronic flight information system (EFIS) that he had built on his kitchen table, and Chelton Flight Sytems (then Sierra Flight Systems) went to work on a three-dimensional, synthetic vision flight display.

Dynon Avionics began selling a low-cost EFIS in 2003 that combined 10 aircraft instruments into a single, easy-to-read display that cost about as much as an attitude indicator alone. But all of those instruments lacked technical standard order (TSO) approval and were meant for Experimental aircraft—not FAA-certified airplanes.

“GA pilots would come up to us and say, ‘Hey, that’s an awesome piece of technology. Can I get one for my Bonanza?’” Richter said. “Our only reply was, ‘Sorry. You’ve got a certified airplane. You can’t have one.’”

Today, however, the variety of new avionics, and avionics manufacturers, has blossomed. Start-up firms including Advanced Flight Systems, Blue Mountain, Dynon, Grand Rapids Technologies, and TruTrak Flight Systems are making IFR-capable experimental flight displays. Aspen has sold and delivered more than 1,000 of its certified glass-panel primary flight displays (PFDs) for the GA fleet. And larger firms including Avidyne, Bendix/King, Chelton, Garmin, and L-3 are producing new certified glass-panel avionics for GA aircraft.

Dynon said the first EFIS displays it sold five years ago were meant for VFR only. But as the Washington-based company expanded its offerings and collected data from more than 6,000 units sold, it has begun encouraging pilots to use them as primary IFR instruments—with appropriate backups.

The federal aviation regulations give avionics manufacturers wide latitude under the Experimental category. The regulations spell out the minimum instrumentation required for IFR flight (FAR 91.205) but the FAA doesn’t require certified or TSOed avionics for Experimental aircraft. Some aircraft owners also obtain FAA field approvals on an individual basis to install non-TSO back-up instruments in certified aircraft, although that can be a cumbersome, time-consuming, and sometimes fruitless paper chase.

TSOs state minimum performance measures, and some experimental avionics makers claim their products are built to TSO specifications. Those claims can’t be verified without independent testing, documentation, and quality control for the entire manufacturing process.

TruTrak founder Jim Younkin, an avionics designer with a history of innovations dating back to the 1950s, said freedom from TSOs allowed him to design, test, and patent an attitude direction indicator (ADI), a single electronic instrument that replaces vacuum-powered attitude indicators and directional gyros. TruTrak sells ADIs for $1,025, and the company uses the same technology in an experimental EFIS with a retail price of about $4,000.Younkin said TruTrak has delivered about 5,000 autopilots and 3,000 ADIs for experimental aircraft. Non-TSO TruTrak autopilots will be offered in Cessna 162 SkyCatcher light sport aircraft.

“The problem with TSOs is that, in my experience, they close the door to new concepts,” said Younkin, 79, who has designed both certified and experimental equipment. “Our ADI embodies principles for which TSOs haven’t been written. I’m interested in moving technology forward and providing a service that will do people some good. I’m not at all interested in bureaucracy.”

“A very sizeable market”

Larger avionics manufacturers Garmin and Chelton build glass panels for both certified and experimental aircraft. And both companies have concentrated on building integrated avionics systems for factory-new aircraft and high-end experimental airplanes. Garmin developed its fully integrated G1000 avionics system in 2003, and those robust, highly automated suites have been broadly adopted in new certified airplanes ranging from Cessna 172s to Citation Mustangs, Diamond DA-40s to Socata TBM 850s, and a growing number of very light jets.

But Garmin also offers the nearly identical G900 for some experimental aircraft, and both units use common parts and software. At a retail price of $66,745, however, the G900 is meant for a small niche in an already limited experimental market. (Garmin doesn’t release a retail price for its G1000 and sells them only to manufacturers of new certified aircraft.)

However, Garmin also targeted the existing GA fleet with its G600, a two-screen system that replaces gyro-mechanical six packs with a PFD and shows terrain, traffic, weather, and approach plates on a colorful MFD. The G600 was announced in 2006 and deliveries were supposed to start the following year, but certification delays altered that timeline. Garmin got FAA approval for the G600 in mid-2008 and began selling the units for $29,772 excluding installation. The units require a GNS 430, 480, or 530 GPS to drive them.

Aspen also is targeting the existing GA fleet with its EFD 1000, a PFD that it touts as a drop-in replacement for vacuum-powered attitude indicators and directional gyros. Aspen’s PFD also has a horizontal situation indicator powered by GPS or navigation radios. Aspen got the FAA’s green light to start selling and installing its PFDs in early 2008, and retail prices range from about $6,000 to $10,000 depending on features. Aspen products are designed with future upgrades in mind, so buyers can increase their avionics capability without replacing the hardware.

Stein Bruch, president and CEO of Stein Air, a Minnesota avionics shop whose clients include both experimental and certified aircraft owners, says the GA market has enthusiastically embraced glass-panel technology, in new airplanes and retrofits. “The days of steam gauges and vacuum systems are over—and everybody knows it,” Bruch said. “There’s increasing competition among avionics manufacturers targeting the GA market. The good news, for them, is that it’s a very sizeable market.”

The existing GA fleet in the United States includes about 170,000 piston-engine aircraft, and the experimental fleet counts roughly 30,000 registered planes. The GA fleet added 2,755 new piston aircraft in 2006; 2,675 in 2007, and was on track for about 2,500 deliveries in 2008. The experimental fleet is adding about 1,000 new airframes a year.

Bruch says the quality and reliability of experimental avionics vary widely in both components and design. “Just because you’re looking at a computerized display doesn’t mean the information it’s showing is totally trustworthy,” he said. “You’ve got to consider what’s driving the display. Can a single-point failure cause the entire screen to do dark? Will the information still be accurate if the pitot system ices up, or the GPS fails?”

Grand Rapids Technologies founder Greg Toman said some experimental units come off the same assembly lines as certified products and are equally reliable—but not all. “The FAA’s testing is overkill and the benefits come at an extremely high cost—but there are benefits for consumers,” he said. “When it comes to experimental avionics, it’s buyer beware.”

Information at their fingertips

Experimental avionics firms Blue Mountain, Dynon, Grand Rapids, and TruTrak say they will keep focusing on the experimental and LSA markets and won’t
seek FAA certification for their products.

Richter, the Blue Mountain founder, said FAA certification would slow development and dramatically raise the cost of his company’s experimental EFIS units that currently range from about $3,500 to $15,000. He said that technical advances proven in experimental avionics are steadily making their way to certified instruments—and that’s the way the system is supposed to work.

“We’re like the guys at the racetrack who are always pushing the limits,” Richter said. “The stuff that wins on the racetracks generally shows up on the street a few years later. That’s the way it works in the world of experimental avionics, too. We’ve got a semi-symbiotic relationship with the certified avionics manufacturers.”

Garmin also plans to avoid the TSO process on its G300 avionics package designed for the Cessna SkyCatcher. The G300 is also the foundation of Garmin’s portable GPSMAP 696, a weighty GPS that went on the market in late 2008.

PS Engineering, manufacturer of a variety of TSO-approved audio panels and intercoms, recently entered the experimental avionics market with its PMA9000EX audio panel which adds features such as a wireless telephone connection and a built-in MP3 player.

The LSA category is the single biggest wild card for avionics manufacturers, and both large and small avionics firms are moving aggressively into this new area.

Aircraft manufacturers hoping to build customer loyalty are betting that student pilots who learn to fly in airplanes equipped with a particular avionics brand will want to stay with the same flight displays, computer logic, and switchology as they progress to more complex and capable aircraft.

Pilots who fly airplanes with technologically advanced avionics devote significant amounts of time, effort, and expense in learning new avionics systems and staying proficient. Jessica Myers, a Garmin spokeswoman, said those investments are making avionics preferences a key driver in airframe purchases.

“A student pilot who learns to fly in a Cessna 172 today can move up Cessna’s entire product line and stay with a G1000 panel the entire time,” Myers said. “Pilots who become accustomed to having all that information at their fingertips don’t want to give it up.”

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