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Sunday, May 1, 2011

Synthetic Vision

Suppliers of synthetic vision systems, valued by pilots for both safety and situational awareness, strive for operational credits for the technology

By Ed McKenna

The key argument for synthetic vision systems (SVS) has always been safety. The technology, which delivers real-time, color 3-D imagery of the terrain outside the aircraft to the pilot, is broadly praised for boosting pilot situational awareness, driving SVS sales for corporate and general aviation aircraft and helicopters.

Some vendors now are eyeing even bigger returns, seeing a place for SVS in the cockpits of at least some air-transport category aircraft.

There is little argument about whether SVS can boost pilot performance, especially during IFR approaches. Regardless of the weather or time of day, pilots can use SVS to see surrounding terrain and airports up to 40 miles away.

A big part of the pilot’s job is gathering data “from the airspeed indicator, altimeter, course deviation indicator, maps, charts, ground speed … and building a mental picture of what is happening,” said Ben Kowalski, director of aviation OEM Sales with Garmin International. “Synthetic vision builds that mental picture,” and saves the pilot “an enormous amount of mental legwork,” he said.

Gordon Pratt, vice president of business development with Cobham Avionics, agreed. SVS technology reduces the pilot’s workload and headaches by “making every flight like VFR,” he said.

This capability alone is boosting sales, especially to corporate and general aviation aircraft manufacturers for new or soon-to-be introduced platforms, and catalyzing competition among providers including Cobham, Honeywell, Rockwell Collins, Universal Avionics, Avidyne Corp., and Garmin.

For example, Rockwell Collins SVS systems will be part of Bombardier’s Global Vision cockpit for the Global 5000 and Global Express XRS aircraft as part of the company’s Pro Line Fusion avionics suite. Those aircraft will be certified this year with “synthetic capability on the head-down displays and synthetic and enhanced vision on the head-up displays,” said Bob Ellis, Rockwell Collins director of product and systems marketing for commercial systems.

Honeywell’s SmartView SVS already is available as an upgrade for Primus Epic-equipped Gulfstream jets and is installed on more than 170 aircraft. “We are certifying on four or five other types of aircraft, and developing (a version) for helicopter and transport and regional aircraft,” said Chad Cundiff, Honeywell vice president of Crew Interface Products.

Garmin is providing its Synthetic Vision Technology capability with the G1000 avionics suite for Embraer Phenom 100s and 300s and Cessna Citation Mustangs, said Kowalski.

However, “there is interest, but less pull right now from the retrofit corporate jet market,” said Matt Carrico, senior engineering manager of advanced concepts for commercial systems with Rockwell Collins. The resistance is partly due to the fact that operators can “get situation awareness, but not operation awareness credit for synthetic vision.”

The question of operational credit is not only holding up retrofit sales but also the potential for using SVS technology on air transport aircraft.

A lot of airlines are “interested in the technology, but in the airline world today, it has got to buy its way on” (the aircraft), said Cundiff.

Gaining the go-ahead to reduce decision height for some ILS approaches can translate into tangible returns for operators by eliminating weather delays or flight cancellations. “We have some data that shows, for instance, that at most airports in the U.S. there are about 150 to 200 hours a year when weather is too low for landing. If we could lower the decision height by even 50 feet, (those airports) would be able to stay open,” Cundiff said. “This doesn’t apply to airports that are CAT III autoland, but it does apply at Chicago Midway and San Diego (International Airport) and a lot of the regional airports.”

For now, the question of operational credit is being considered by RTCA Special Committee 213, jointly with Eurocae WG-79, which has been tasked by FAA with developing minimum aviation system performance standards (MASPS) for synthetic vision and the range of Enhanced Flight Vision Systems (EFVS), Enhanced Vision Systems (EVS) and Combined Vision Systems (CVS).

The issues specifically related to the SVS case are being addressed in a draft document, RTCA DO-315B. At this point “the system referred to in (that document) is proposed to be used on an SA (straight-in approach) CAT I ILS approach,” said FAA. Beyond that, the specific features and architecture remain “hypothetical” since “actual SVS designs being developed to achieve instrument approach credit are unique in many proprietary ways.”

Despite these differences, FAA stressed that it is still “useful to describe one concept and system architecture as a basis for minimum standards, from which the actual systems being developed may vary and show equivalence.” The agency also said it “has not established a schedule for implementing operational credit for SVS.”

In its initial work, “FAA at least hinted that they would be receptive to looking at providing credit down to (a decision height of) 150 feet for a suitable system,” said Carrico. The current minimum is 200 feet for a CAT I ILS approach.

In the meantime, SVS vendors are developing systems to bolster their current positions and prepare themselves for a future market.

Rockwell Collins believes its decision to put SVS on the head-up display might give it a leg up in the battle for approval for operational credit. “We believe with HUD, we can get credit to go below 150 feet,” said Carrico.

“There is significant advantage in having a natural transition from IMC (instrument meteorological conditions), where you see a synthetic representation of world, to the conformal visual representation as you come through the obscuration layer,” said Ellis. Studies done years ago with NASA showed “that the transition phase, if it is mechanized in a wholly heads-up environment, is a much more natural way to fly.”

The Rockwell Collins SVS system includes other features “that the pilots really like,” said Ellis. For example, “we draw a dome feature over the intended landing airport that is visible when you are 20 to 30 miles away,” he said. “As you get closer to it, the dome starts to fade out, and you see the runway outline.”

Like the other vendors, Honeywell deploys its SmartView SVS head-down on the primary flight display. “With HD displays, we’ve got a deep color palette (with) texturing and shading,” said Cundiff. “We can display a lot of information including HUD symbology. But when the pilots go out the window, we want them to be flying the aircraft with reference to what they are seeing out the window, so on a HUD you give them (just) the flight path marker, acceleration chevron, and speed and altitude tapes.”

At the heart of SmartView is Honeywell’s Enhanced Ground Proximity Warning System (EGPWS), which has chalked up more 800 million flight hours since it was introduced 15 years ago to combat controlled flight into terrain and approach accidents. “We know of 50 accidents that have been ‘saved’” by the EGPWS system, Cundiff said.

In the quest for operational credit or competitive advantage, vendors are exploring the use of SVS and EVS in tandem, incorporating infrared images of the external situation. Honeywell and Gulfstream have been awarded a $1.2 million contract from NASA to test Synthetic and Enhanced Vision Systems for the NextGen flight environment. The tests will investigate using Honeywell’s SVS as low as 100 feet above threshold and then transitioning to Gulfstream’s EVS, developed by Kollsman Inc., of Merrimack, N.H., and using it to land.

“With our initial systems, we are allowing the pilot to choose a synthetic or enhanced vision scene or nothing,” said Rockwell Collins’ Carrico. “They may choose to stick with the EVS scene; if not they can switch to SVS (and use it) as low as the certification approvals will allow.”

FAA contends that “each of these components are potential sources of error and failure modes.” However, “the use of enhanced vision to augment the SVS presentation offers the benefit of an independent ‘picture’ of the forward view of the runway that can serve to validate the correctness of the SVS picture.”

On a more practical level, the key to Garmin’s approach to the market is scalability, said Kowalski. The company offers systems that can be used on a variety of platforms from light sport and turbine aircraft through the Phenom 300 business jet. Depending on the platform, the systems could have different sized screens, fewer features and different price points, he said.

Garmin sells its G1000, G3000 and G5000 avionics suites to OEMs who pursue their own approaches when it comes to synthetic vision. “A lot of them, like Embraer and Cessna, sell it as an option on their aircraft,” said Kowalski. For other manufacturers, like Cirrus Aircraft, it is a standard safety feature.

The SVT capability comes pre-installed on Garmin’s G600 avionics retrofit package, and is available as an add-on for the G500. And Garmin is now offering a helicopter version of its retrofit suite.

Garmin will not be alone in the helicopter market, however. Honeywell is developing a helicopter SVS system, and Cobham has already carved out a healthy niche in the market — tallying late last year, for example, a contract to provide the Los Angeles County Sheriff’s Department its Synthetic Vision Electronic Flight Instrument System (EFIS) for the department’s fleet of 14 Eurocopter AS 350 B2 helicopters.

The Cobham Synthetic Vision EFIS has been approved for about 740 fixed-wing and rotorcraft models, including many Bell helicopter models, the Eurocopter AS 350 and King Air, Citation 501, Cessna single and twin, Piper single and twin, Piaggio Avanti and Pilatus PC-12 fixed-wing aircraft models.

Helicopters offer somewhat different challenges from fixed-wing aircraft.

“The lower you fly as a rule, the terrain is an issue,” said Pratt. However, the EFIS product is essentially “the same for helicopter and fixed-wing aircraft,” he said.

The Cobham system includes Highway in the Sky (HITS) navigation “which is a tunnel in space that traces your intended route from your flight management system,” and a hover vector that allows the pilot to determine his hover performance,” Pratt said.

Now on software version 8, Cobham has added new features to the system, some of them derived from pilot feedback.

“They come up with very clever and creative ways to use the system,” said Pratt. For example, “customers asked us to do a mark-to-target for our hover vector.” They “wanted to be able to essentially drop a biscuit on the Earth, and then hover relative to that biscuit.”

The company accommodated pilots by introducing a waypoint in the system to designate or mark on a target. “The pilot can just push a button on one of his control sticks, put a symbol on the map and then hover relative to that symbol,” Pratt said. This feature would allow a law enforcement operator over a suspected crime scene to maintain a very precise location at 1,000 feet and keep the cameras pointed in a certain direction while supporting assets on the ground. It is also used for search and rescue missions.

Other SVS vendors report equally productive relationships with pilots who use or test their systems. At Honeywell, “they are very much part of the design team,” said Cundiff. Pilot suggestions “drove us to integrate a lot of the heads-up display information on to” the SmartView system.

“We have more pilot eyeballs on the synthetic vision HMI (human-machine interface) than almost anything else we have done over the past decade,” said Rockwell Collins’ Carrico.

“They have been key members of our development team throughout, going all the way back to the original studies with NASA pilots. And, more recently, customer technical pilots and FAA and Transport Canada pilots have been partners with us throughout the development program for Global Express.”

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 segments. Avionics Product Focus Editor Ed McKenna can be contacted at emckenna@accessintel.com

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