By TARA BURGHART
Associated Press Writer
CHICAGO (AP) -- A new ground radar system designed to prevent runway collisions at the nation's busiest airports loses accuracy during snowstorms at O'Hare Airport and can fail to see snowplows, baggage carts and other vehicles, the president of the local air traffic controllers union warned on Thursday.
Joseph Bellino, president of the O'Hare affiliate of the National Air Traffic Controllers Association, said the system is putting the public in danger.
"When we say `cleared to land,' we're saying that runway is clear of all obstructions on the runway. If it's snowing, we say it, but we're keeping our fingers crossed," he said.
The Federal Aviation Administration denied the situation is as bad as Bellino portrayed it, and said it usually takes a year to fine-tune the software to account for differences in airport layout and weather. The system has been in operation at O'Hare - the nation's second-busiest airport and one of its snowiest - since July.
"The controllers union leadership shouldn't be trying to scare the public," said FAA spokesman Tony Molinaro. He said ground radar is a "secondary tool" used by controllers trained to use their eyes and conversations with pilots to avoid problems.
Molinaro also said the system is better than its predecessor at helping controllers keep track of objects other than planes. The old system sometimes produced false or duplicate images during heavy rain.
No collisions have been blamed on the new system, called Airport Surface Detection Equipment, Model X, or ASDE-X.
Jeff Gilde, president of Louisville International Airport's controllers local, said that on the eve of the Kentucky Derby in early May, a heavy rain "made the system go completely blank, and it did not come back up."
"Basically, the tower visibility was zero. So we could not see out the window and we could not see anybody on radar," he said. "And we actually had an aircraft cross in front of another aircraft that was landing."
Gilde said most of the airport's initial problems with the system have worked out, but estimated false system alarms result in a plane not being allowed to immediately land at Louisville once every couple weeks.
"For a safety system to be 100 percent effective, it should work 100 percent of the time, and this does not," Gilde said.
The technology was first installed at the Milwaukee airport in 2003 after years of testing. It is now in operation at 11 airports, with plans for 24 more by 2011, according to the FAA.
The FAA acknowledged that during a heavy snowstorm earlier this month, ASDE-X had trouble correctly identifying long lines of snowplows and other movements on the ground at O'Hare.
In a statement, the agency said it is looking into whether the problem could be solved by equipping ground vehicles with transponders - electronic devices used by airplanes to send out an identifying signal.
The Milwaukee and St. Louis airports had similar trouble during the first year ASDE-X was in operation there, Molinaro said.
On average, it snows 32 days a year at O'Hare, according to the National Weather Service. So far this winter, it has snowed 37 days at O'Hare. The Government Accountability Office, the investigative arm of Congress, reported last month that O'Hare had the nation's second-highest number of near-collisions on runways between 2001 and 2006.
Bellino said he is particularly concerned about construction trucks at O'Hare as part of a $15 billion expansion.
Air traffic controllers in the Chicago region have also complained recently that they are weary and more error-prone because of repeated six-day work weeks. The FAA has said staffing is adequate. But the Transportation Department has opened an investigation of work conditions at O'Hare and FAA installations in the suburbs.
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