Avionics: Reality Show

Three years after rival Garmin introduced Synthetic Vision Technology for its G1000, Avidyne is finalizing its own version of a GPS-derived view of the outside world that promises many new innovations.

Avidyne’s Synthetic Vision System (SVS) for Entegra Release Nine (R9) presents a colorful, nearly photo-realistic picture of the surrounding terrain as well as three-dimensional traffic and terrain warnings with visual and aural alerts. It also allows pilots to broaden or narrow the SVS field of view, zoom in to focus on distant objects, and split a single PFD screen between SVS and a top-down, two-dimensional, moving map view—or an “enhanced vision system” (EVS) from an infrared camera.

“The reason I joined Avidyne a decade ago was that I was fascinated by the idea of synthetic vision,” said Steve Jacobson, vice president for product management at Avidyne and a former U.S. Air Force test pilot. “The concept of a true fusion of data to improve pilot situational awareness was very exciting—and now that concept is a reality.”

Avidyne expects to provide the final engineering and test data to the FAA this summer for certification. Once approved (and Avidyne says it has no idea how long FAA approval will take), the company plans to provide SVS to existing R9 customers through a software upgrade without additional charge. The retail price for SVS to new buyers, however, will be about $10,000.

As is its custom, Avidyne is using its new product to provide the technical foundation for future upgrades. SVS, for example, will be capable of fusing with EVS at some later date to create a combined GPS/video view of external reality in all weather conditions. SVS and its visual and aural terrain warnings may also provide the basis for an FAA-certified TAWS-B system.

Some features that differentiate Avidyne SVS from other FAA-certified and non-TSO, GPS-based systems are subtle but significant.

As with Garmin SVT, flags resembling those you’d find on a golf course help identify distant airports, but Avidyne takes the additional step of color-coding each flag (red, yellow, green, and blue for low IFR, IFR, marginal VFR, or VFR) based on current METARs. Also, the pilot can alter the SVS field of view from its default 45-degree position with a single, dedicated knob. The 45-degree view closely matches the picture a pilot would normally see out the windshield. But that view can expand to a fish-eye view of 120 degrees—or narrow to a spotlight of just 20 degrees. Pressing the zoom knob restores the normal 45-degree field, and turning it zooms in and out.

Jacobson says he uses the wide-angle view to get the big picture of terrain ahead, and then he zooms in once established on the final approach course to confirm line-up, obstacle clearance, and the numbers on the threshold that identify the landing runway.

“I was skeptical about the pilot-selectable field of view at first, but it’s really quite useful,” he said. “It correlates to what you see outside, it makes sense, and it’s a nice, nice cross-check.”

The SVS traffic display uses standard symbols that avionics manufacturers developed for TCAS more than a decade ago. It’s designed to show traffic according to relative position, movement, and threat level. A distant airplane, for example, appears as a small, hollow diamond. As it gets progressively closer, it grows into a solid diamond, then a yellow ball, and finally a big yellow ball. Arrows next to the symbols show whether they are climbing or descending, and aural callouts tell their distance and clock position. (For example: “Traffic, 12 o’clock, two miles, same altitude.”)

“The traffic symbols are a bit cartoonish, but we made them that way because it makes them almost impossible to ignore,” Jacobson said. “We want our pilots to be trained like Pavlov’s dogs. When they see a threat, they should recognize it and respond immediately.”

Approaching the destination airport for landing, runways appear bordered in magenta on the SVS screen. During an instrument approach to a particular runway, however, only the landing runway has magenta edges. Runway numbers also appear on the SVS as well as white-striped centerlines. “It’s going to be very hard to land on the wrong runway with this system,” Jacobson said.

Terrain in the Avidyne SVS appears yellow when it’s within 1,000 feet below an aircraft’s altitude and red when it’s within 100 feet. Obstacles within five miles and 2,000 feet of aircraft altitude are encircled in blue “threat bubbles.” As the obstacles get nearer, threat bubbles turn yellow at 1,000 feet below, and red within 100 feet. The altitude of each obstacle (in feet msl) also appears next to each one.Airports also have a rectangular “suppression area” around them to prevent pilots from getting nuisance warnings of false hazards.

Avidyne equipment has earned a well-deserved reputation for being easy for pilots to learn and use, and SVS continues that legacy. There’s an SVS tab and a Nav Display tab on the R9, and either one can control how SVS is displayed (or whether it’s displayed at all).

Rocker switches on the R9 flight displays also simplify operation because there are relatively few buttons, or button combinations. Avidyne also offers pilots the flexibility to customize the ways they display SVS information on each screen, but not too much.

“The goal is to provide the right compromise between flexibility and simplicity,” Jacobson said. “Maximum flexibility can also create maximum confusion. We think we’ve found the right balance.”

Avidyne has been test flying SVS in two airplanes, a Cirrus SR22 and a Piper Saratoga. Both airplanes have made multiple test flights throughout the southern Appalachian Mountains in North Carolina, Georgia, and Tennessee and Jacobson said the fidelity between the in-flight images on the SVS screens and the rocky mountain ridges passing by is remarkable. “It’s almost like watching a video of what’s going on outside,” Jacobson said. “You see hills, valleys, lakes, and ridges on the screen that seem to correspond almost exactly to what you see outside the airplane. SVS is going to provide a lot of operational utility—and it’s going to be an integral part of some very intriguing concepts we’ll be working on in the future.”

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