Wednesday, October 1, 2008
Cover Story: SVS Virtual Sight Lines
From their beginnings in general aviation, Synthetic Vision Systems are becoming increasingly popular in new piston planes and higher-end business jets
Humans are visual creatures — if forced to give up one of our five senses, not many of us would choose to be blind. Living in a dark or blurry world is a scary thought, so we tend to pursue anything that enhances vision, from eyeglasses and binoculars to lights and Lasik.
Add synthetic vision to the list, probably somewhere below electric light, but definitely above corrective surgery. Currently available from several manufacturers who cover just about the entire aviation spectrum, Synthetic Vision Systems (SVS) present aviators with real-time, color 3-D imagery of the terrain outside the aircraft, even when the real thing is invisible due to weather, darkness or whatever. The pretty pictures are splashed across a multifunction display, behind the normal flight and navigation information found on a typical glass panel.
In addition to terrain, synthetic vision displays towers and other obstructions, airports, runways and the paths leading to them.
Developed within the last 10 years, synthetic vision is becoming increasingly popular, especially at the upper end of the business jet market and in new piston-powered GA planes.
On a flight earlier this year between Washington Dulles International (IAD) and Roanoke, Va., Regional Airport, (ROA), Honeywell gave reporters a look at its Integrated Primary Flight Display (IPFD) installed in a company-operated Gulfstream G450. Honeywell test pilots said the only complaint they get from guest pilots during demonstrations is when they turn off the magic, restoring the 2-D, blue-over-brown world that just minutes before was all the average aviator thought he would ever need.
"As soon as we turn it off, they say, ‘Hey, I want that back!’" related Honeywell Test Pilot Jary Engels.
Gordon Pratt, president and co-founder of Chelton Flight Systems, Mineral Wells, Texas, expects synthetic vision to become commonplace on owner-flown airplanes and business jets. Adding the capability to an Electronic Flight Instrument System (EFIS), once you get through the certification hurdles, really doesn’t add any cost, he said. All the cost is driven by the environmental requirements that are imposed on the equipment — hardening it against vibration, electromagnetic interference, high-intensity radiated fields, salt spray and other hazards.
Significant growth, Pratt believes, will come when synthetic vision can be marketed for operational benefits. Currently, the capability is marketed as a safety enhancement. However, the industry’s Holy Grail is a fusion of synthetic vision with enhanced vision to reduce approach minimums or shorten trips; in short, things that save operators money.
"I think that’s where synthetic vision is going to have to go, especially as you move up the food chain," Pratt said.
Among companies offering SVS systems are Honeywell, Rockwell Collins, Universal Avionics, Chelton Flight Systems, Blue Mountain Avionics, Avidyne Corp., L-3 Avionics Systems and Garmin.
The synthetic vision can be complimented with Enhanced Vision Systems (EVS), which project images from an infrared sensor onto a head-up display (HUD). Honeywell’s Gulfstream uses an EVS from Kollsman, Merrimack, N.H., a system certified to pick out the visual cues required by Federal Aviation Regulations for legal landings in instrument conditions.
Simply stated, synthetic vision makes every day virtually VFR. While moving-map GPS displays did wonders for situational awareness, synthetic vision takes it to new levels while also reducing pilot workload.
On the Honeywell demonstration flight, the 10-by-13-inch LCD displays of Gulfstream’s Primus Epic-based PlaneView flight deck revealed a copy of the Appalachian Mountains scrolling along thousands of feet below the aircraft, displayed in the same colors that depict elevation variation on a VFR sectional chart. As the aircraft descended, relevant obstructions, such as tall transmission towers, came into view on the screen.
Within 15 miles of Roanoke, a line of "bread crumbs" appeared, showing the way to the runway selected in the FMS. The imagery blends with flight data presented with the same symbology as on the HUD, making transition to synthetic vision easy enough that no training is required for pilots with HUD experience. Energy management and aircraft control are facilitated through a flight-path marker, another carryover from the HUD. The system is designed to provide relevant information as necessary, so you don’t see 300-foot-high towers while cruising in the flight levels.
In contrast to systems targeted at light aircraft, Honeywell chose not to include "highway in the sky" (HITS) markers. With input from pilot testers, the company decided the HITS boxes, which outline the aircraft’s projected route like a series of soccer goals, cluttered the display without adding any value. While weekend pilots might enjoy flying through the hoops, the annoyance factor is likely to increase in direct proportion to a pilot’s experience level.
Recognizing this, Garmin said users of its Synthetic Vision Technology (SVT), designed for use with the company’s G1000 avionics suite, can make the boxes vanish by pressing a single button.
When installed on Primus Epic-equipped Gulfstream G350, G450, G500 and G550 business jets, the Honeywell system is known as the Synthetic Vision-Primary Flight Display (SV-PFD). Honeywell was working to certify the system on other Epic-equipped aircraft, including the Dassault Falcon 900EX, 2000EX and F7X, the Embraer EMB-170 and -190 family of regional airliners, and the Hawker Beechcraft Hawker 4000 and Hawker Horizon, as well as the Agusta AB-139 helicopter.
In April, Honeywell announced it had signed an exclusive licensing agreement with Mercury Computer Systems, Chelmsford, Mass., for the latter’s VistaNav synthetic vision intellectual property and product line. Honeywell assumed sales and support of the VistaNav Cockpit Information System, now part of Honeywell’s Bendix/King product line. The company in July introduced the AV80R Vision 3D and AV80R Horizon 3D, both synthetic vision-capable EFBs.
The Rockwell Collins Pro Line Fusion system, which can include synthetic vision, was chosen for Bombardier’s Global Express XRS, Global Express 5000, Learjet 85 and the recently launched C Series regional airliner, the Cessna Citation Columbus, Embraer’s Legacy 450 and Legacy 500 and the Mitsubishi Regional Jet. Rockwell Collins also is looking at technology insertion programs to put certain elements of Pro Line Fusion, including synthetic vision, in the cockpits of aircraft equipped with the older Pro Line 21 system.
Chelton Flight Systems and Blue Mountain Avionics, Copperhill, Tenn., a supplier of homebuilt and light sport aircraft, pioneered SVS systems in the late 1990s. Chelton’s FlightLogic EFIS with computer-generated terrain and HITS flight guidance was approved by FAA in 2003 for retrofit on GA aircraft participating in the Alaska Capstone demonstration program.
Universal Avionics, Tucson, Ariz., said its Vision-1 SVS system with "Exocentric View" was certified by FAA in 2002, initially for use on the company’s MFD-640 multifunction display. Universal was awarded a STC for Vision-1 with "Egocentric View" on Part 23 general aviation aircraft in 2005. In May 2006, the company announced STC approval for Dual Vision-1 systems with both views on Part 25 air-transport aircraft.
The Egocentric View allows the pilot to see a computer-generated image of the terrain ahead of the aircraft and is designed for Universal Avionics’ primary flight display and Electronic Attitude Display Indicator applications.
The Exocentric View, which is shown on the navigation display, provides a "wingman’s" view of the aircraft and terrain from a position situated behind, above and to the right of the aircraft, based on the FMS flight plan.
In another example of the blending of SVS and EVS technologies, Universal Avionics markets the SureSight M-Series EVS from CMC Electronics, a subsidiary of Esterline Corp. The infrared sensor, when interfaced with Universal’s EFI-890R large format display, MFD-640 display or Universal Cockpit Display EFB, improves a pilot’s situational awareness at night and during periods of reduced visibility, minimizing the risk of Controlled Flight Into Terrain (CFIT) accidents. SureSight also can be used in conjunction with CMC’s PilotView EFB.
More recently, Avidyne Corp. and L-3 Avionics Systems unveiled SVS offerings in separate announcements at EAA AirVenture in Oshkosh, Wis., in July. Avidyne, Lincoln, Mass., added SVS and EVS capabilities to its Entegra flight deck. L-3 Avionics Systems, Grand Rapids, Mich., added synthetic vision to its SmartDeck avionics suite.
Synthetic vision systems from Avidyne, Chelton, Garmin and L-3 can be added to just about every new GA aircraft, from Cessna 172s to King Air turboprops. Garmin’s SVT is available from OEMs Cessna, Cirrus, Diamond, Mooney and Socata.
It is hard to believe that a pilot armed with synthetic vision, if awake and paying the slightest attention, could fly a plane into the ground in instrument conditions. Of course, similar things were said about TAWS and GPWS.
Since then, some flight crews have proved their ability to defy technological safeguards. But synthetic vision will force that subset of aviators bound on self-destruction to work especially hard to become CFIT casualties.
Some might say that a pilot who follows the rules of IFR flight has nothing to worry about anyway. But even skeptics would breathe easier with synthetic vision in the panel while performing the most challenging, potentially risky procedures commonly faced by modern commercial pilots — night visual approaches, especially to strange aerodromes and doubly so in the mountains. Throw in an engine problem and power loss that brings an aircraft closer to the granite and a pilot would happily give up important body parts for a computer-generated view of what lurks beyond the windshield.
"The primary benefit of EVS/SVS that you can’t put a dollar value on, is situational awareness," said Michel Merluzeau, an analyst with G2 Solutions, Kirkland, Wash. Even without enhanced vision, the presence of synthetic vision on GA and business aircraft would have saved "a heck of a lot of lives," he added.
Five to 10 years from now, FAA may allow the use of SVS to reduce landing minima, Merluzeau said, but there are many issues to tackle before then. On the technical side, there are such things as GPS and database integrity. Operationally, regulators will have to decide what pilots would be required to see during an instrument approach before transitioning from the computer-generated imagery to visual flight in order to land the aircraft.
Any new technology demands users educate themselves and even exercise a little self-discipline to prevent slavish dependence on gadgetry from replacing basic piloting skills or common sense. Otherwise, we could see a situation where CFIT decreases but midair collisions increase. Although synthetic vision systems also show traffic, there’s no excuse for not looking outside, weather permitting. Like TCAS, synthetic vision is supposed to help pilots find the "unsynthetic" threat faster, not add to the distractions that keep heads buried deep in cockpits.
While not exactly cheap, the price of synthetic vision systems won’t shock general aviation customers, especially considering what they’re already shelling out for new airplanes, even single-engine pistons. For $9,995, Diamond Aircraft says it will add Garmin’s SVT to its DA-40 G1000 avionics package, a veritable bargain for anyone planning to use the airplane for serious instrument flying.
Synthetic vision is being driven by business jets and private aircraft, but industry sources believe it will eventually make its way into the Part 121 world of scheduled airlines. The improved situational awareness certainly sells well in corporate aviation, where aircraft can go to any of thousands of airports around the world and crews frequently fly into unfamiliar fields.
"There’s a level of situational awareness that simply sells in the business aviation market," said Tim Rayl, senior director of marketing for Business and Regional Systems at Rockwell Collins. "It seems to me that in the 121 market it either requires a mandate or a strong economic value proposition that means there’s some kind of benefit and the CFO will vote for putting it on."
Airlines, which concentrate on a much smaller number of airports that they know intimately, are more interested in technologies such as Required Navigation Performance and 4-D trajectories, which pay immediate dividends by reducing fuel costs or opening up better routes to difficult airports, Merluzeau said.
Ultimately, synthetic vision will become as commonplace on business jet flight decks as FMS is now, Rayl said. That is easy to believe considering where manufacturers such as Rockwell Collins want to take the technology in the future.
For one thing, Rockwell Collins has already demonstrated the fusion of synthetic and enhanced vision in a heads-up display. Commercial availability of that technology is about three years out, said Dave Wu, the company’s director of flight deck systems marketing for Business and Regional Systems.
"We think for all the value you get from synthetic vision head down, that’s multiplied by some factor when you put it head up," said Rayl.
There are some technical challenges, he said, because one display you look at and the other you look through, but they share the same database and symbology. The goal is to make the transition between head up and head down "much more seamless and smooth."
Future plans include new ways to use the synthetic vision screens to show FMS flight plans and nav data along with terrain imagery. The challenge, Rayl noted, is to add value without clutter.
Rockwell Collins also sees the technology playing a role in FAA’s NextGen program and the Single European Sky initiatives for future air-traffic management.
The situational awareness offered by synthetic and enhanced vision, as well as the data processing and display capabilities of SVS, could facilitate efforts to move more planes through the air and at busy airports.
Air-to-ground communications are still conducted over open party lines allowing a controller to speak with only one air crew at a time — a strange situation in the early 21st century that leads to some exciting moments at big airports during rush hour.
Wu said Rockwell Collins has demonstrated surface guidance concepts in which instructions are sent via datalink from the tower to an aircraft, so that pilots get their post-landing taxi instructions automatically on both the HUD and MFD without chatter between tower and cockpit.
"These technologies depend on databases very similar to synthetic vision," said Wu. Pilots would see the speed they should taxi at (or directions to stop to avoid a conflict) as well as the boundaries of taxiways and runways in a fused SVS/EVS picture in their HUD. At the same time, the MFD would display the situation on a moving map.
The idea is to take advantage of the wealth of data that can be collected and transmitted from the ground for exploitation by pilots, for example, new ground-traffic systems that gather data from their own primary radars and retransmit it for display on a synthetic view.
Synthetic Vision Valued In Helicopter Industry
As with fixed-wing aircraft, synthetic vision is becoming rooted in the helicopter industry.
Chelton Flight Systems’ Synthetic Vision Electronic Flight Instrument System (EFIS) uses 3-D graphics to translate terrain ahead of and around the helicopter into a real-time visual image. The system has supplemental type certifications for Bell 204, 205, 206, 210, 407 and 427 models, the Eurocopter AS 350/355 and EC-120B, and the MD Helicopters MD520N.
In July, Chelton announced European Aviation Safety Agency (EASA) approval of the EFIS for the Bell 206A, B, L-series and 407 single-engine helicopters. This was the first European certification for synthetic vision installation, the company said.
About half of Chelton’s business comes from the rotorcraft market, said Gordon Pratt, president and co-founder. The company, based in Mineral Wells, Texas, has seen tremendous growth in synthetic vision from helicopter operators, especially those involved in emergency medical services, special missions and electronic newsgathering, for whom Controlled Flight Into Terrain accidents are a constant danger.
"There’s just a huge groundswell of helicopter movement right now, because synthetic vision really does solve a lot of the helicopter problems," said Pratt.
Honeywell plans to offer synthetic vision as part of the Primus Epic integrated avionics suite for the Agusta AB-139. France’s Thales planned to offer SVS as part of its TopDeck avionics suite for the new Sikorsky S-76D. The latter, twin-engine helicopter, featuring all-composite main rotor blades and other enhancements, is slated for deliveries in 2010.
Synthetic vision is one of several technologies, including enhanced vision, radar and fiber-optic lasers, being studied by the U.S. military to protect helicopters against accidents due to "brownouts" caused by rotor-blown debris.
In May 2007, Sikorsky Aircraft was awarded a contract under the Defense Advanced Research Projects Agency "Sandblaster" program to demonstrate solutions for landing a helicopter in degraded visual conditions.
Sikorsky is teamed on the 18-month project with Honeywell and Sierra Nevada Corp., of Sparks, Nev., to develop a synthetic vision system that fuses real-time imagery from a 94 GHz radar developed by Sierra Nevada with onboard terrain and obstacle databases. The system is targeted initially for U.S. Army UH-60M Black Hawks.