Synthetic vision systems provide pilots with unprecedented awareness

July 2, 2009
Nothing is more dangerous for a pilot than when he is blind as to where his runway is – whether this is due to poor weather conditions or unfamiliar terrain. Therefore pilots need technology that can be their eyes in hazardous conditions.

By John McHale

Nothing is more dangerous for a pilot than when he is blind as to where his runway is – whether this is due to poor weather conditions or unfamiliar terrain. Therefore pilots need technology that can be their eyes in hazardous conditions.

In other words they need synthetic vision, technology that combines sensors and state-of-the art heads-up avionics display graphics. Two companies leading the way with this technology are Honeywell Aerospace in Phoenix and Rockwell Collins in Cedar Rapids, Iowa.

The technology has come quite a long way, says Sergio Cecutta, product and marketing manager at Honeywell Aerospace. Honeywell's synthetic systems – called Integrated Primary Flight Displays (IPFDs) – are used in Gulfstream and Dassault jets providing them with VFR data no matter the conditions outside the aircraft, he adds. The IPFD uses Honeywell's Enhanced Ground Proximity Warning System (EGPWS) database and HUD symbology.

In fact the graphics are so easy to use that the FAA has said the system on the Gulfstream equipped with the PlaneView advanced cockpit does not require pilot training, Cecutta says. It is so intuitive they can use it as soon as it is turned on, he adds.

Pilots say they most need this technology when flying between mountains or approaching a destination they've never been before," Cecutta says. Even if the destination is Houston, if the pilot has never been there it will have unfamiliar structures and terrain, he adds.

For synthetic vision systems Rockwell Collins' "Pro Line Fusion is equipped with Synthetic vision technology," says Adam Evanschwartz, senior marketing manager, Business and Regional Systems at Rockwell Collins. "We are exploring the possibilities of offering this technology on Pro Line 21."

According to a Rockwell Collins release Pro Line Fusion uses "high resolution 15-inch diagonal LCD displays working in concert with head-up guidance systems (HGS), graphical flight planning, synthetic and enhanced vision and the company's MultiScan hazard detection system."

"Today, users evaluate the perceived effects of SVS on the pilots awareness of aircraft position relative to terrain, obstacles, airports, and runways, and the attendant effects on the crew's mental workload," Evanschwartz says. Users often look at these types of things together, and then form a notion regarding the strength of a system's ability to reduce the risk of controlled flight into terrain.

"Aesthetics are a frequent topic of conversation," Evanschwartz says. I often hear pilots discussing graphics quality, realism, the smoothness of movement in the display, etc. Richness in elevation coloring, shading and texture effects, display size, resolution, sharpness, etc. are the key variables here."

According to the company website Honeywell's IPFD features "include: - flight path marker based PFD – HUD symbology that helps with the aircraft energy management and eases navigation; - conformal terrain – displays exactly where you are going by looking at the Flight Path Marker; - color coded terrain – Similar to how it is conventionally displayed on a map; - water texturing and color saturation – clearly distinguishes the water from the sky; - EGPWS warnings and cautions overlaid on the terrain; - range rings – show distance; - obstacles;
- runways markings – centerline, runway numbering, and distance remaining markers; and
- unusual attitude declutter with fade-in – when the aircraft is in an usual attitude the terrain is gradually faded away to allow the pilot to concentrate on the task of returning to steady and level flight."

It is also very important when designing these systems to work with the pilots and get a handle on the human factor, Cecutta says. The displays are "not just pretty wallpaper," they provide three dimensional terrain and accuracy of 600 feet by 600 feet ground resolution, he adds. Honeywell is developing technology that is as accurate to 300 by 300 feet, Cecutta notes.

"It's all about improving the situational awareness for the pilot," Cecutta says.

"Naturally, usability and human-machine interface are also important," Evanschwartz says. "Are the symbols included in the synthetic scene, and the basic aircraft information that overlays the SVS display easy to interpret? Does all of the information on the display work together to enhance awareness of the airplane's position relative to terrain, obstacles, airports, and runways? Or could some part of the display become distracting?

Designers of military aircraft are also looking at synthetic vision soluitions in various programs.

Honeywell engineers worked with Sikorsky in Stratford, Conn., on a Defense Advanced Research Project Agency (DARPA) contract called Sandlblaster, Cecutta says.

The goal of the research contract was to demonstrate technology that would reduce helicopter landing accidents caused by brownouts – when a pilot is blind just before landing in desert conditions, Cecutta says.

Honeywell provided the synthetic vision part of the contract, he adds. "We were able to bring the pilot vision of the ground for when he couldn't see out the window," Cecutta notes.

Honeywell successfully demonstrated the technology from the air with a U.S. Army Blackhawk helicopter, he continues.

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