Virtual Vision

AVIATION LEGEND JIMMY DOOLITTLE made the first "blind" landing in September 1929, a little more than 80 years ago. He used an experimental Sperry gyroscope to serve as his artificial horizon and then-revolutionary radio beacons to home in on the runway.

Up until the last few years, most pilots continued to fly in clouds pretty much the same way. But with advances in GPS and the coming of "synthetic vision" systems and infrared "enhanced vision," pilots can now see the equivalent of an HD television picture of the real world right in front of them. It's as though they have the ability to, virtually, lift the canvas hood that Doolittle used to restrict his vision.

Here's how synthetic vision works. Start with GPS technology. The satellites' job is telling the pilot exactly where the airplane is, which way it's headed and how fast it's moving. And they do that with remarkable precision. In the beginning, GPS delivered all that information to pilots with numbers, but they still had to consult paper maps to visualize and monitor their intended route.

As display screens increased in quality, we began to see "moving maps" in the cockpit, with a tiny airplane symbol showing where we were. I clearly remember years earlier practicing my instrument flying with the first versions of Microsoft Flight Simulator and occasionally cheating by pausing the game and switching to the overhead God's eye screen. With airborne moving maps, I now cheat on every flight. I still can't hit "pause," however.

Now add a stunningly detailed world-mapping database. If you're impressed by Google Earth, which is meant for free mass consumption, imagine what can be accomplished when military and commercial budgets are unleashed. With a dash of the progress we have all seen in computer animation, manufacturers of aircraft navigation systems have turned the God's eye view on its side, and pilots can now see on their screens what they would out the window-if the terrain and obstacles were not obscured by cloud or fog. And instead of spinning mechanical gyros, we now use far more reliable and precise solid-state motion sensors-the same kind used in cars' automatic braking systems and stability-control technology. The combined system for aircraft is called a synthetic-vision system (SVS), and it turns flying into a real-world video game-albeit with higher stakes for losing.

Earlier screens replicated the surface of traditional mechanical gyros like Doolittle's. Solid blue on top represented sky, and solid brown underneath represented the Earth. SVS, with its view of mountains, rivers and other terrain features, removes one more layer of the interpretation required when flying by instruments. That makes pilots' jobs more intuitive and safer. Not only that, but the new navigation screens can show obstacles getting artificially larger (and turning bright red) as they get closer. And with traffic-alerting systems, other airplanes in the flight path can also be shown prominently on the screen when they might have been invisible in the real-world view.

And finally, even small aircraft are now being fitted with complementary "enhanced vision" systems known as EVS. These consist of cameras, mounted on the wing or nosecone, using infrared technology to cut through darkness. If the GPS terrain database can show exactly where the touchdown point is, the EVS can alert the pilot if a deer or another airplane is lingering on the runway, even under pitch-dark conditions or in haze. EVS, however, cannot see through clouds.

Top-line business jets have had these features for some time, but what's new for general aviation is lower prices. Since there are mass-market applications for improved display screens, computer data capacity and motion-sensor technology, performance has leapt forward even as component prices have plummeted. That means that pilots and passengers in smaller business aircraft can benefit from these technologies. Flying even small single-engine airplanes is getting easier and safer and becoming a more reliable form of personal transportation. 

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