SIMULATED SKIES
AMES TO MAKE AIRPORT TESTING 'AS REAL AS IT GETS'

WHEN air traffic controllers develop new ways to speed the flow of aircraft in and out of the world's busiest airports, they now have no choice but to use real planes with real people -- and run real risks.

Next year, using Silicon Valley-based technology, they'll be able to run virtual-reality tests instead at the world's first airport operations simulator dedicated to research and development. It is now under construction at NASA/Ames Research Center in Mountain View.

Researchers will be able to simulate realistically any airport in their database, testing technologies and procedures to move airliner traffic more efficiently, in the air and on the ground.

After all, said Stan Harke, the National Aeronautics and Space Administration simulator project manager, air traffic problems rarely occur en route. ''Airports,'' he said, ''are the bottlenecks of the whole damn system.''

The simulator has a name -- the Surface Development and Test Facility -- that, like many government labels, doesn't give much of a clue as to the significant work it will do.

The $9.3 million simulator, which will be housed in a two-story structure inside a larger building at Ames, will have the look and feel of an air traffic control tower cab.

The aircraft moving through the skies or taxiing on the ground will be computer-generated, as will airport buildings, the weather and just about everything else.

''This will be the only one of its kind in the world,'' Harke said. ''This will be as real as it gets.''

The image-generation system will provide a realistic view of weather and environmental conditions, the seasons, and the movement of more than 200 aircraft on the ground or in the air.

''I can make you whatever you want,'' Harke said, explaining not only the view out the window but also the control functions inside the cab. ''Los Angeles is on the screen; just push a button, boom, there's Chicago, or Atlanta.''

You want fog in the simulation? You got it. You want rain, or dusk, or snow, or high wind? You got it with a few computer keystrokes.

The 360-degree view from the tower cab will consist of images from a pair of million-dollar graphics computers from Silicon Graphics Inc. projected on 12 screens just outside the windows. But the controllers, ''pseudo-pilots'' and other airport personnel involved in the simulation will be real, communicating with one another by simulated radio transmissions. That way, human factors will be researched as well as how best to move airplanes and their passengers.

'A human in the loop'

''This is simulation with a human in the loop,'' Harke said. ''It's more difficult than just with a computer.''

So what kind of problems could the simulator tackle? Just about anything, Harke said.

Here are a few hypothetical examples:

• To ease the flow of traffic into San Francisco International Airport and reduce aircraft noise under certain weather conditions, planners want to know whether changing the traffic pattern and arrival and departure corridors would help.

  The designers think the new procedures will work. But if they don't, the Bay Area's biggest airport can expect a massive snarl.

  Instead of changing things right off the drawing board, the FederalAviation Administration could send a team of San Francisco's controllers to Ames to simulate the new procedures to find out whether they are flawed.

• San Jose International Airport plans to build a third passenger terminal and to lengthen one of its secondary runways to handle jetliner traffic. But what effect will construction have on aircraft movement on the ground? And how will the availability of two major runways affect aircraft traffic? The simulator could provide the answers before the first shovelful of dirt is turned over.
• An accident shuts Oakland's main airliner runway, dumping traffic onto its shorter landing strips or diverting aircraft elsewhere. Is the Oakland emergency plan workable, and what effects would the situation have on other Bay Area airports? The simulator could disclose how to ease the operational pain.