FAA Reviewing System "Issues"

During a heavy downpour the evening before the Kentucky Derby, a Northwest Airlines DC-9 mistakenly crossed an active runway where another aircraft was on final approach at Louisville International Airport.

SDH air traffic controllers said they could not see the DC-9 that had just landed and were, thus, unable to warn it not to cross that runway, according to the Associated Press.

The new radar system, an Airport Surface Detection Equipment Model X, or ASDE-X, had just malfunctioned - and not for the first time, according to controllers.

The ASDE-X system is designed to track aircraft and other vehicle movement on airport grounds and uses part of the airport's old system. It has been in the testing phase since its March 11 launch.

There is no backup system.

Federal Aviation Administration spokeswoman Laura Brown denied any collision danger, but did acknowledge the agency is looking at "issues" with the Louisville radar system.

"There were no other planes in the immediate vicinity that presented a potential conflict with the plane on the runway," she said.

Jeff Gilde, president of the Louisville chapter of the National Air Traffic Controllers Association, said the inbound traffic was only about a minute from landing. Because of both weather and the radar failure, "we would not have known anything had happened unless two airplanes hit and there had been an explosion," he said.

Roman Blahoski, a Northwest spokesman, said in a statement the NWA aircraft had "landed without incident" and was not "involved in a runway incursion at (the airport). Although the DC-9 aircraft did cross (the active runway) upon landing ... there were no conflicts with any other aircraft, and at no time was passenger safety in jeopardy."

Northwest is cooperating fully with the FAA review, he said.

Gilde wrote the FAA's air traffic manager in Louisville three days after the incident, saying "we have had a number of very serious issues with this (radar) system that cannot be ignored." "I do not need to tell you how lucky we were not to have a catastrophic event," Gilde said, referring to the Northwest incident. "This is an unacceptable safety risk, and something needs to be done to stop this system from being certified until such time it works properly."

The new technology is not ready for regular use, according to Gilde and Chuck Morrison, president of the local chapter of the Professional Airways Systems Specialists, the technicians who maintain the system.

"I knew that with any new system, we were going to have trouble with it," Morrison said. But, he said, "We've had a significant number of unscheduled outages of this system."

At least one other airport has reported frequent problems with the system, in Seattle, according to the AP. ASDE-X systems are now operating at airports in Atlanta, Houston (Hobby), Providence, Seattle/Tacoma, Orlando, St. Louis, Milwaukee and Hartford and is due to be installed in Chicago soon.

According to Morrison, there are times when the radar screen goes blank. At other times planes or vehicles just "drop off the screen" or are never detected in the first place.

"Whenever you have a storm ... the controller can't see as well," Morrison said. And "the pilot can't see as well. That's the time you need the system the most." Instead, controllers were left without any ground radar, he said. "That's when you have a recipe for an accident," Morrison said.

Since the radar was activated, the Louisville area has had four major rain storms and each time the system failed, for different reasons, he said.

Glide said the rain was coming down so hard that controllers could see nothing out the tower windows on May 4, the eve of the Derby. About 6:30 p.m., Northwest Flight 1246 landed on Louisville's eastern parallel runway, using its entire 7,800 feet.

Pilots then turned the plane around and taxied along a taxiway that runs parallel to the runway before being instructed by controllers to turn left toward the terminal onto a runway that was not in use.

The plane instead turned right for unknown reasons crossing the runway they had just landed on.

"The pilot did not tell us he crossed the active runway until he was on the other side of it," Gilde said. The ground radar at that time? It was "a blue screen - it was blank," he said.

After being notified of the error, the Northwest plane was told to wait while the second aircraft landed, Gilde said. It then re-crossed the active runway to the terminal. He said he did not know what type of plane landed while the Northwest jet waited.

According to Brown, Louisville's ground radar is "still in the testing phase."

"We are in the process of looking at issues that have come up during the testing," she said. When there is severe weather "there's potential for limited use" of the ground radar. But pilots and controllers still have procedures for talking to each other by radio and ensuring that instructions are being followed, she said.

She said that what happened in Louisville "happens very infrequently anywhere with ASDE-X" and it "generally" performs better in bad weather than the old one did. The FAA is testing a "rain mode" for this radar system that would allow it to see vehicle movement more accurately during heavy rains, she added.

Senator Patty Murray, D-Wash., told a Senate subcommittee hearing Thursday in Washington that in the last 15 months controllers in Seattle have filed 480 reports of false targets or false alarms.

"We would love this system to work," Glide said. "But when it doesn't, we have to cry foul."

FMI: www.flylouisville.com