'Seeing' Through Fog

February 24, 1993|By Ted Shelsby | Ted Shelsby,Staff Writer

Engineers at the Maryland Advanced Development Laboratory in Greenbelt believe they are getting close to perfecting a relatively low-cost electronic system that will allow airline pilots to "see" through fog and land their planes.

Norris J. Krone Jr., president of the nonprofit research center established by the University of Maryland to convert technology into products, said the system could go a long way toward easing traffic congestion and the long delays at airports caused by inclement weather.

Under current Federal Aviation Administration regulations, he said, pilots have to break out of their landing approaches at 200 feet if they can not see the runway below. They are required either to circle the airport in a holding pattern until the fog clears or are detoured to other airports.

While the FAA does not keep figures on flights delayed by fog, Henry Price, a spokesman for the federal agency, said 65 percent of the more than 280,000 flight delays last year were caused by weather problems. It is a safe assumption, he said, that fog was a factor in many of those delays.

Dr. Krone has been testing the system in a specially outfitted twin-engine Cessna. At the heart of the fog system is the infrared camera and high frequency radar tucked into the nose of the plane. Both the camera and the radar can penetrate the fog and project an image of what they see on a heads-up display borrowed from the F-16 fighter jet and mounted at eye-level just in front of the plane's windshield.

In addition to providing an electronic view of the airport, the display gives pilots other vital information they need to control the plane, like air speed and altitude.

"It was real foggy over Harrisburg," Dr. Krone said last week after a test flight. "The equipment worked. We could have landed."

The infrared "works fine in light fog," said Dr. Krone, who has a Ph.D. in aeronautical engineering from the University of Maryland In heavy fog, he explained, the high frequency radar is called upon to serve the same role.

Dr. Krone said the system also would work well "in normal snowstorms but not in the kind of blinding blizzards you have in the Yukon."

With financial support from the FAA, several airlines and a number of major manufacturers, Dr. Krone said, the center was trying too produce a system that would be affordable for use on planes as small as corporate jets and commuter craft.

Dr. Krone says there is already an autoland system on the market that will do what he's trying to accomplish, but "it's very, very expensive" and limited to just a few of the bigger planes like the 747, DC-10 and some British Airbus models.

This system, which he estimated would cost $1 million or $1.5 million, is designed to automatically land a plane in adverse weather without the pilot touching the controls.

The Greenbelt laboratory's system is not being designed to do all the things the autoland does, but would be limited to increasing a pilot's visibility in adverse weather. The aim is to produce a system that would sell for about $200,000, said Dr. Krone.

In addition to the high cost of autoland, Dr. Krone said, planes using it are limited to airports that have what he called "type-two" radar beams on runways to guide planes in for landings. He estimated that only about one of every 10 airports in this country has the type-two system.

The laboratory's goal is to have its system approved by the FAA and ready for production within two years.

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