Thursday, September 3 Dallas-Fort Worth International Airport

"DFW, this is American 1137, heading 125 at 3500."

"Roger American 1137, got you loud and green. Maintain 125, full circle 40 miles then 215 for 40."

"Traffic Dallas?"

"Heavy. Weather"s been strong. On again off again. Piled up pretty good."

"Sheers?"

"None so far. Ah, you"re a "37, you carry a sheer monitor. You got it made. Have to baby sit some 0"s and "27"s. May be a while."

"Roger Dallas. 125 40, 215 40. Maintaining 12 point 5."

"Roger 1137."

The control tower at DFW airport was busier than normal. The dozen or so large green radar screens glowed eerily and made the air traffic controllers appear pallid under the haunting light emitted from around the consoles. Severe weather patterns, afternoon Texas thunderstorms had intermittently closed the airport forcing a planes to hold in a 120 mile pattern over Dallas and Fort Worth.

Many of the tower crew had been at their stations for 2 hours past their normal quitting time due to street traffic delays and highway pileups that had kept shift replacements from arriving on time. Planes were late coming in, late departing, connections were being missed. Tensions were high on the ground and in the air by both the airline personnel and travelers alike. It was a chaotic day at Dallas Fort Worth International Airport.

"Chad? Cm"ere," said Paul Gatwick, the newest and youngest, and least burnt out of the day shift flight controllers.

Shift supervisor Chad Phillips came right over. "What you got?"

He asked looking at the radar screen.

"See these three bogies?" Paul pointed at three spots with his finger.

"Bogies? What are those symbols?"

"They just appeared, out of nowhere. I don"t think they"re there. And over here," he pointed, "that was Delta 210. It"s gone." Paul spoke calmly, in the professional manner he was trained. He looked up at Chad, awaiting instructions.

"Mike," Chad said to the controller seated next to Paul. "Switch and copy 14, please. Fast." Chad looked over to Mike"s screen and saw the same pattern. "Paul, run a level 2 diagnostic. What was the Delta pattern?"

"Same as the others, circle. He"s at 45 doing a 90 round."

"Tell him to hold, and verify on board transponder." Chad spoke rapidly and his authority wasn"t questioned.

"Mike, see if we can get any visuals on the bogies. They might be a bounce."

Chad took charge and, especially in this weather, was concerned with safety first and schedules last. In less than a minute he had verified that Delta 210 was not on any screen, three other ghost planes meandered through the airs.p.a.ce, and that their equipment was functioning properly.

"Dallas," the calm pilot voice said, "American 1137, requesting update. It"s getting a little tight up here."

"Roger, 1137," Gatwick said nervously. "Give me a second here . . ."

"Dallas, what"s the problem?"

"Just a check . . ."

Chad immediately told the operator of the ETMS computer to notify the FAA and Department of Transportation that a potential situa- tion was developing. The Enhanced Traffic Management System was designed to create a complete picture of every airplane flying within domestic air s.p.a.ce.

All status information, on every known flight in progress and every commercial plane on the ground, is transmitted from the 22 ARTCC"s, (Air Route Traffic Control Centers) to an FAA Technical Center in Atlantic City and then sent by land and satellite to a DoT Systems Center. There, an array of DEC VAX super mini com- puters process the constant influx of raw data and send back an updated map across the ETMS every five minutes.

Chad zoomed in on the picture of the country into the DFW ap- proach area and confirmed that the airplanes in question were not appearing on the National Airs.p.a.ce System data fields or dis- plays. Something was drastically wrong.

"Chad, take a look here!" Another controller urgently called out.

His radar monitor had more bogies than Paul"s. "I lost a Delta, too, 1258."

"What is it?"

"37."

"s.h.i.t," said Chad. "We gotta get these guys wide, they have to know what"s happening." He called over to another controller.

"Get on the wire, divert all traffic. Call the boss. We"re closing it down." The controllers had the power to close the airport, and direct all flight operations from the tower. Air- port management wasn"t always fond of their autonomy, but the tower"s concern was safety at all costs.

"Another one"s gone," said Paul. "That"s three 37"s gone. Have they had a recall lately?"

The ETMS operator asked the computer for a status on 737"s else- where. "Chad, we"re not the only ones," she said. "O"Hare and LAX have problems, too."

"OK, everybody, listen up," Chad said. "Stack "em, pack "em and rack "em. Use those outer markers, people. Tell them to believe their eyes. Find the 37"s. Let "em know their transponders are going. Then, bring "em down one by one."

The emergency speaker suddenly rang out. "s.h.i.t! Dive!" The captain of American 1137 ordered his plane to accelerate ground- ward for 10 seconds, descending 2500 feet, to avoid hitting an oncoming, and lost, DC-9.

"Dallas, Mayday, Mayday. What the f.u.c.k"s going on down there?

This is worse than the freeway . . ."

The emergency procedure was one they had practiced over and over, but rarely was it necessary for a full scale test. The FAA was going to be all over DFW and a dozen other airports within hours, and Chad wanted to be prepared. He ordered a formal notification to Boeing that they had identified a potentially serious malfunc- tion. Please make your emergency technical support crews avail- able immediately.

Of the 100 plus flights under DFW control all 17 of the Boeing 737"s disappeared from the radar screen, replaced by dozens of bogies with meaningless signatures.

"Dallas, American 1137 requests emergency landing . . .we have several injured pa.s.sengers who require immediate medical a.s.sist- ance."

"Roger, 1137," Gatwick blurted back. "Copy, EP. Radar status?"

"Nominal," said the shaken American pilot.

"Good. Runway 21B. We"ll be waiting."

By 5:00 PM, Pacific time, Boeing was notified by airports across the country that their 737"s were having catastrophic transponder failure. Takeoffs were ordered stopped at major airports and the FAA directed that every 737 be immediately grounded. Chaos reigned in the airline terminals as delays of several hours to a day were announced for most flights. Police were needed to quell angry crowds who were stuck thousands of miles from home and were going to miss critical business liaisons. There is nothing we can do, every airline explained to no avail.

Slowly, the planes were brought down, pilots relying on VFR since they couldn"t count on any help from the ground. At airports where weather prohibited VFR landings, and the planes had enough fuel, they were redirected to nearby airports. Nearly a dozen emergency landings in a two hours period set new records that the FAA preferred didn"t exist. A field day for the media, and a certain decrease in future pa.s.senger activity until the shock wore off.