Business & GA, Commercial, Embedded Avionics

Synthetic Vision Systems

By By Ed McKenna | May 1, 2012
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Rockwell Collins SVS, as pictured on the Heads-Up Guidance System of its test aircraft flying over Washington state.

As synthetic vision systems become more mainstream, technology providers are refining their offerings to appeal to a wider range of customers. Along with general and business aviation operators, key targets include the rotorcraft and commercial transport markets. For the latter, however, the technology’s main asset situational awareness will need to be bolstered by the potential for economic returns gained mainly through operational credit for using SVS.

“Synthetic vision is no longer a ‘fringe’ technology; every major avionics manufacturer has some form of synthetic vision, and it is certified in every class of aircraft,” said Gordon Pratt, director of business development, Cobham Commercial Systems.

For business jets, SVS is now not being seen as an option but “is expected to come with new aircraft,” said John Peterson, director of avionics and flight controls marketing at Rockwell Collins. The same is true for the retrofit market, added Dan Reida, vice president of marketing with Universal Avionics Systems, of Tucson, Ariz. “As a matter of fact, it is a negative if it is not available with whatever (avionics) system they are contemplating retrofitting.”

The chief selling point for SVS, which delivers real-time, color 3-D imagery of the terrain outside the aircraft to the pilot, is situational awareness. When “visibility is less than ideal,” people appreciate “the enhanced situational awareness … that it can provide not only for IFR but for VFR flying as well,” said Jim Alpiser, director of aviation aftermarket sales for Garmin. The system can identify key threats, such as towers and mountains, and can show pilots traffic that is in front of them using data from Mode S data link or an active onboard traffic system. Pilots can use features common to many of the systems, such as the flight path marker and airport runway diagrams, to ensure a “safe approach and arrival,” Alpiser said. 

Garmin’s G3000 integrated flight deck includes the SVT Synthetic Vision Technology, which features simulated 3-D perspective topography on the 14.1-inch diagonal primary flight display.

Along with helping to prevent Controlled Flight in Terrain, the system provides pilots with a “wonderful sense of confidence” which is particularly helpful to “lower time owner operator pilots who may not like flying in lower minimums and weather,” said Peterson.

On safety merits alone, SVS has drawn interest from OEMs and operators across markets from general aviation to the airlines. “I believe (Boeing is) leaning very favorably towards putting synthetic vision… on their next clean sheet airplane, and I know Airbus has done some presentations putting a simplified version of SVS on their head-up display,” said Sarah Barber, principle systems engineer for advanced concepts at Rockwell Collins. 

Universal Avionics Systems PFD with Vision-1 SVS shows the Egocentric, or pilot’s, view.

SVS in Air Transport

When it comes to actual sales for existing aircraft, however, the air transport market is “not as bullish on it,” said Peterson. There are a couple of key interrelated stumbling blocks: “The displays are not set up to take the synthetic vision yet … and the cost to get the technology on the aircraft is still quite a bit of a barrier.”

In the air transport business, operators “won’t do it until they can get measurable credit (for using the technology) which provides a measurable return on that investment,” Reida said. “There are exceptions … small exceptions we’ve got a cargo airline in Europe that is installing it (but) in general the CRJs and ERJs flying in the U.S. are not adopting.”

To change this situation, avionics companies are crafting new policies with regulatory agencies in the RTCA Special Committee 213 (SC-213). Set up in 2006, this committee, which operates jointly with Eurocae WG-79, has been tasked by FAA to develop minimum aviation system performance standards (MASPS) for synthetic vision and the range of Enhanced Flight Vision Systems (EFVS), Enhanced Vision Systems (EVS) and Combined Visions Systems (CVS). At least from the avionics companies’ point of view, a key goal is to devise rule changes that would allow operators using synthetic vision to lower their decision height on IFR approaches from the current 200 feet down to 150 and ultimately to 100 feet.

This is “something we are working on now with a lot of focus,” said Larisa Parks, vice president of marketing and product management at Honeywell. The change could save “operators a significant amount of money related to those diversions or go-arounds” associated with missed approaches due to weather. On average, a simple go-around can cost the airline about a $1,000. “If an airline has to divert (the aircraft) to another airport, the average cost to the operator would be $3,000,” she said. Those estimates don’t take into account the costs to airports and passengers and the delays in delivering cargo.

To date, the committee has published several documents including last June the “DO-315B MASPS, which lays out the system requirements for doing the first step for extra credit, which is essentially getting additional 50 feet on SA CAT 1 (approach),” said Barber, who participates in the committee. The next document is expected to be published later this year or early next year, she said.

Cobham said its Synthetic Vision Electronic Flight Instrument System (EFIS) combines HUD symbology with real-time, forward-looking terrain on the primary flight display for enhanced situational awareness and automated flight management capabilities.

Key Challenges

The key challenges companies face in boosting the use of the SVS is “insuring in the integrity of the database,” said Reida. One solution for that would be “a fusing of or at least a comparison of EVS (which projects data from aircraft infrared sensors) and SVS,” he said. For example, “an IR camera might pick out a mountain … against a dark sky, and then you can take that (image) and match it with the same feature on SVS … to help ensure the integrity of your SVS image.”

Addressing that issue, Honeywell is developing a Combined Vision System, “which combines our (certified) synthetic vision … with certified IR imagery from of (Merrimack, N.H.-based) Kollsman,” said Parks. The combined system will enable “us to create an improved experience for lower landing minima by taking these two relatively mature technologies … and delivering them in a single solution,” she said. “We are in the process of the final development and starting to talk to the FAA and customers related to the certification plan.”

At the same time, Honeywell is continuing “to invest in the baseline SmartView SVS” and, after chalking up a healthy share of the early adopters, it “is just starting to work with the next wave of operators,” Parks said. To date, Honeywell’s SVS is available on Gulfstream and Dassault aircraft. 

Honeywell said it is in final development of a combined synthetic and enhanced vision system, which will offer “improved experience for lower landing minima by taking these two relatively mature technologies and delivering them in a single solution.”

Unlike Honeywell, which provides its SVS on a heads-down display, Rockwell Collins has deployed its SVS on the head-up display (HUD), which it believes gives it practical and operational advantages especially when it comes to retrofitting systems on transport or business aircraft. To begin with, it is “a lot simpler” to deploy the technology to the HUD, said Peterson. In addition, “one of the major benefits of doing (SVS) on head-up, particularly when you are going for these lower minima (approaches), is that it really turns the transition from the instrument segment to the visual segment into a seamless exercise,” said Barber.

Along with transport or business aircraft, Rockwell is also targeting lighter aircraft with its new compact HGS-350 HUD with synthetic vision. The HUD “doesn’t have a projector all of visual imaging is in the combiner portion of it so it is smaller … and it fits in smaller aircraft like King Air turbo props,” Peterson said. The company is also upgrading its Pro Line 4 aircraft, including the Falcon 2000 and 2000EX, from cathode ray tube to liquid crystal displays and bringing in graphical charts, maps and weather and “later this year they will be putting synthetic vision on,” he said.

Universal Avionics rolled out Vision-1+ SVS last year at the National Business Aviation Association (NBAA) annual conference. “It is still the plus and the enhancements are still in development,” said Reida. The company is taking advantage of the availability of higher resolution terrain data in that effort. The company is focusing in on “depicting the runways that can be a challenge with this (technology) and the extended runway environment.

“We looked at the centerline and then realized if you just extend … the sides of the runway out … (you can provide) a better understanding of your position relative to that approach course,” he said. The company is also looking at integrating traffic and even weather data, which he said pose a number challenges.

At Cobham, “we constantly improve our product based on customer feedback and our own developments, typically resulting in a software release every nine to 12 months,” said Pratt. The company added “video input capability to support infrared camera and mission computer input” to its system. “We are also now shipping our new 6-by-8-inch displays for military and special-mission applications; a civil version will be available later this year,” said Pratt. Cobham has seen “tremendous growth” in sales to special-mission aircraft both fixed-wing and helicopter (that) are being modernized rather than replaced,” he said. “Integrating our all-digital avionics into older special-mission aircraft with their host of legacy analog sub-systems is always challenging, but we have completed so many now that it is not as difficult or time-consuming as it was a few years ago,” he said. “Once a new electrical interface is defined and accommodated, and the software symbology is created, it is simply a case of application engineering to adapt it from one platform to another.”

In general terms, the rotorcraft market has provided an attractive new marketplace for SVS. Rockwell this year installed its Pro Line 21 Integrated Display System with SVS on the Sikorsksy S-61 and it is “looking at” (Eurocopter) AS332 Super Puma, said Peterson. “There are some environmental conditions that are a little different, such as (increased) vibration … but our product migrates across platforms, (and) we don’t have to have a different part number,” he said. Since the company’s products are rated Level A software, they lend themselves to the IFR rated Part 29 heavy helicopters, such as the S-61.

Universal Avionics is also rolling out helicopter versions of its SVS-related products. The EFI-890H flat panel display for helicopters comes with software based on Universal’s fixed-wing display and hardware proven and approved to withstand high-vibration environments, the company said. The unit will be approved for Sikorsky S-76A, S-76C, S-61L, S-61N, UH-60L; Bell 212, 412, 412EP, 412CF; Eurocopter EC-155, Dauphin N1, N3 and AS-332 helicopters.

Aside from accounting for the vibration, the most significant challenge in deploying SVS in helicopters is dealing with the required terrain warning systems. The alerting criteria are considerably different for rotorcraft than for fixed wing platforms since helicopters operate closer to the ground and obstacles, and regulations allow companies, like Garmin, “to develop a reduced protection mode” that conforms more closely to helicopter operations, said Alpiser. Garmin’s G500H a helicopter version of its fixed wing retrofit product includes a Synthetic Vision Technology option, and will be on the Bell Relentless 525, and the company is providing its G1000H avionics suite with SVT for the new Bell 407GX.

The company has also introduced what it calls 3-D vision, the AERA 796, a portable GPS receiver with synthetic vision features, minus attitude information, for use on both fixed wing and rotorcraft. On its 7-inch touchscreen, it shows “you a kind of behind the aircraft look out the window, so the horizon line doesn’t turn left and right as the aircraft turns left and right, but it stills shows you that 3-D picture of what is front of you,” including towers, obstacles and traffic, Alpiser said. It is less capable than an SVS but costs $2,500 compared to $5,000 for a G500 with synthetic vision, plus installation and certification costs, he said.

Avionics Magazine’s Product Focus is a monthly feature that examines some of the latest trends in different market segments of the avionics industry. It does not represent a comprehensive survey of all companies and products in these markets. Avionics Product Focus Editor Ed McKenna can be contacted at [email protected].

Next month: Real-Time Operating Systems

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