Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, September 23, 1993 TAG: 9309230028
SECTION: NATIONAL/INTERNATIONAL PAGE: A-6 EDITION: METRO
SOURCE: Associated Press
DATELINE: WASHINGTON LENGTH: Medium
Many controllers have written to NASA, which monitors aviation safety, complaining of planes vanishing from screens and phantom images appearing. In Cleveland, a squirrel chewed through a power line and disrupted the system for more than a week.
The Federal Aviation Administration said there are some problems but insisted that the state-of-the-art system generally works very well and is improving air safety.
The system is called ASR-9, short for airport surveillance radar. It began operating in 1989 and is being used in 62 airports, including eight military bases. That total is expected to more than double by 1995.
The National Aeronautics and Space Administration said it has received many complaints at its Ames Research Center at Moffett Field, Calif., home of NASA's aviation safety reporting system.
And the National Air Traffic Controllers Association said the system could pose dangers in many places.
"The controllers and the pilots make it work," said Will Faville, head of safety and technology for the controllers' union. "It's stretching the rubber band. Pretty soon it could snap."
So far, Faville said, there have been no accidents caused by the system, but there have been close calls.
A midair collision almost occurred in Walla Walla, Wash., in October 1990, the controllers' group said, when the radar did not pick up an aircraft flying at 6,500 feet that came within 200 feet of another plane.
NASA withholds the identities of those who complain. Here are some examples from NASA files:
In Cleveland, a controller said the radar failed at least a dozen times in 18 months.
A jet at Baltimore-Washington International Airport relied on a visual landing over Labor Day weekend in 1990 when the radar failed. Controllers said the system was down for several hours.
Controllers at St. Louis International Airport said there are instances when two planes take off at the same time on parallel runways and one of them disappears from the screen. "It seems to me St. Louis is an accident waiting to happen," one controller wrote NASA in August 1991.
In Pasco, Wash., controllers said they were picking up ground traffic on their scopes, including what they believed to be a car backing out of a driveway.
by CNB