Ghost planes plague O'Hare

May 21, 2000

BY ROBERT C. HERGUTH TRANSPORTATION REPORTER

Air traffic controllers who handle flights around O'Hare Airport are seeing a frightening increase in "ghosts," bogus radar images of airplanes that don't really exist or are actually hundreds of miles away.

Over the last few weeks, at least a dozen such images have mysteriously appeared on radar scopes at the Terminal Radar Approach Control facility in Elgin, according to interviews with air traffic controllers and documents obtained by the Chicago Sun-Times.

At least a few times, controllers said, they have ordered pilots to take sudden evasive actions: "immediate right turn," "immediate left turn," "descend immediately." Such maneuvers, which can put passengers at risk, were later found to be unnecessary.

No near collisions have occurred, but documents give details of the confusion caused by ghost radar images.

On April 19, an air traffic controller spotted a "target" 18 to 20 miles northeast of O'Hare, when the aircraft in reality was departing DuPage County Airport.

Earlier this month, an airplane appeared on the scope north of O'Hare, at 4,000 feet, when actually it was on final approach to Midway Airport, the documents show.

"The ghosting is a complete terror for the air traffic controllers," said Charles Bunting, president of the National Air Traffic Controllers Association local at Elgin.

The control center in west suburban Elgin handles traffic within a 40-mile radius of O'Hare, the world's second-busiest airport. The area's other main air-traffic centers are in Aurora and at O'Hare.

Another problem has cropped up on the same Airport Surveillance Radar-9 scopes, which have been used since 1992. Controllers have seen malfunctions of radar software that displays aircraft altitude, flight numbers and airspeed.

The problems apparently are unrelated but together are increasing opposition by air traffic controllers to the planned resumption of a test procedure that can squeeze more arrivals into O'Hare airspace.

The procedure, known as CAPS, or Compressed Arrival Procedures, vertically stacks airplanes around O'Hare. Already tested on some O'Hare flight corridors, the CAPS procedures would allow stacking of planes only 1,000 feet apart.

"The airlines and the FAA want to do this . . . to reduce delays within the system and get the aircraft here quicker," said Bunting, of the controllers union.

"Our problem is--and we want to do everything we can to enhance the efficient flow of air traffic into the facility--in light of this radar situation that's developing here, we don't feel it's a viable time to conduct these tests when safety can be compromised because of it."

CAPS testing might resume next month, Tony Molinaro, a spokesman for the Federal Aviation Administration, said Friday. But a final decision on whether to implement the stacking on an arrival corridor northeast of O'Hare hasn't been made. Currently, arrivals are typically single file.

Molinaro said the testing wasn't designed to coincide with an expected jump in flight operations caused by the phaseout of O'Hare flight limits.

And Molinaro said that neither the stacking procedures nor the radar "glitches" should worry airline travelers.

"Over the past five weeks there have been 13 unsubstantiated reports, meaning we still need to look into them and see if they're substantiated ghosting events," Molinaro said. "Over that time period you'd expect eight or nine reports from controllers, so it's a little more than normal.

"At the surface they look random, and that's why managers feel they're not a significant problem, but we'll still look at every single one. If someone puts up a construction tower or crane temporarily, those type of things can cause" a ghost image.

But Mike Egan, vice president of the controllers union at Elgin, said Friday the FAA is downplaying what has been an increasingly common occurrence.

"That's a bald-faced lie," he said about the FAA's figure of 13 ghost incidents. "Maybe 130, but not 13. We had a couple of them today, as a matter of fact. I had one this afternoon. . . . They know there's a problem."

Bunting added: "When they first installed [the radar equipment], we had problems. For whatever reason, something has happened. Not only is it back, it is worse than before."

An American Airlines pilot with more than 20 years of experience who frequently flies to O'Hare said he never has had to take evasive action for a "false target." However, he has been asked by controllers to search for an aircraft while he was airborne, only to find out it was a ghost.

He said he's not worried by the increased number of false images, citing his confidence in the onboard Traffic Collision Avoidance System, which alerts pilots of dangerously close aircraft.

But he wishes "the federal government would dig into the trust fund and update the air traffic control system." With new hardware, such glitches could probably be minimized, he said.

Paul Hudson, executive director of the watchdog group Aviation Consumer Action Project, agreed. Noting that some equipment is so old "they don't make it anymore," he said the age alone sometimes contributes to safety problems.

Controllers said another safety problem stems from the radar software, which displays airspeed, flight number and altitude on the ASR-9 scope. The Automated Radar Terminal System has been getting knocked out when the number of flight plans filed by flight crews tops 250. That happens on busy days, when radar might be needed the most.

The FAA said it is working on the problem. "What we found out a few months ago is, if too much flight plan data was stored, the computer program would kick out some data," Molinaro said. "But we found that out immediately, and we do have a contingency for that now. Our technical folks, whenever it's a busy day, they monitor the data storage and every 15 minutes . . . they take out any secondary data so the primary important data would not be touched."

He said an FAA technical center is "working on a patch to fix the glitch, and we expect to get that installed" in August at Elgin. "It truly hasn't caused any delays or posed any safety problems."

But he conceded that some of the software problems, which have taken different forms since new software arrived two years ago, persist at the Elgin center, which last year handled 1.36 million operations.

That's a lot of airline passengers, said David Stempler, president of the Air Travelers Association in Washington.

"The air traffic control system only runs efficiently when the controllers have confidence in their equipment," Stempler said. "This is not good." The FAA "should get it fixed immediately before we do have a safety problem."