It’s 1.30 a.m. as the large-cabin business jet begins its circling approach to an unfamiliar airport located in mountainous terrain. The latest weather observation tells the crew there’s light rain/snow and, yes, fog in the area. Not long ago the flight would have been forced to divert to an alternate airport hundreds of miles away. Not tonight.
Even though the Captain can’t see outside his windscreen, his aircraft’s synthetic vision system (SVS) is giving him a “daylight view” of the airport and surrounding terrain.
Synthetic Vision Is Real
Synthetic vision systems were created by NASA and the U.S. Air Force back in the late 1970s to improve cockpit situational awareness, especially when operating in reduced visibility at low altitudes. Today it’s found in practically every new commercial, business and private aircraft. If your airplane doesn’t have it, there are plenty of companies, including Aspen Avionics, Garmin, Honeywell, Rockwell Collins and Universal Avionics, that offer retrofit SVS solutions.
Using a combination of GPS accuracy, high-speed processors and high-resolution digital terrain maps, including data from the Space Shuttle Radar Topography Mission (SRTM) — another reason why we should have never scrapped the Shuttles — SVS or Syn-Viz creates a realistic, 3D illustration of what you’d see outside the aircraft. Known obstacles, buildings, mountains, etc. are all rendered on the pilot’s primary flight display (PFD). Colors are added to signify the height of surrounding obstacles and terrain. If the ground turns red, you’re dead. More sophisticated systems up the information by adding traffic and navigation symbology. But I’ll save those for another time.
Enhanced Vision: Real Views In Real Time
While Syn-Viz uses stored databases and GPS location information to create its “synthetic” views, Enhanced Vision Systems (EVS) use active infrared cameras (sensors) or even millimeter-wave radar to show a real-time view of what’s directly in front of the aircraft. This gives EVS the capability to display transient obstacles like vehicles, animals, construction cranes — things that probably weren’t there 10 minutes ago, let alone years ago when the Syn-Viz database was developed.
And because EVS is real-time, it’s extremely beneficial for improving safety and awareness during ground operations. Too many runway incursion incidents each year are caused when crews become confused in low-visibility conditions and taxi onto the wrong runway. EVS cuts though fog, smoke and light rain so pilots can easily see taxi and runway markers, signs, ground vehicles and animals, which may have found their way through an airport fence. Astronics‘ subsidiary Max-Viz produces new enhanced vision systems and aftermarket kits for large and small aircraft, including emergency use helicopters.
Best Of Both Worlds
Many aircraft owner/operators are installing both display technologies in their aircraft to give their flight crews the best situational awareness possible. The next short step forward will be a combined SVS/EVS system that will present richly detailed images not only on the instrument panel but also on the Heads Up Display, where they can be overlaid on the real-world view through the windscreen. These new enhancements are making commercial and business aviation safer, and they are allowing unhindered access to airports in conditions that pilots would otherwise consider unreasonable or impractical. That means increased aircraft utility, fewer delays, peace of mind for passengers and crew alike, plus unprecedented enhancements to safety.
In future articles, I will continue exploring these new flight deck and cabin technologies as well as the companies that produce them.