Tracking of jet reviewed
Who watched as flight plan was aborted?


Forty-five minutes. That's how long American Airlines Flight 77 meandered through the air headed for the White House, its flight plan abandoned, its radar beacon silent.

Originally bound for Los Angeles from Washington, it got as far as the Ohio border before terrorists disabled the aircraft's transponder, a piece of equipment that sends a signal back to control centers.

It was about 9 a.m.

At that moment, the north tower of the World Trade Center was already in flames.

Minutes later, a second airliner would crash into the south tower, providing unmistakable evidence that the United States was under terrorist attack.

Meanwhile Flight 77 was turning around, streaking back east over Virginia toward the White House and finally slamming into the Pentagon at 9:45 a.m.

Who was watching in those 45 minutes?

"That's a question that more and more people are going to ask,'' said one controller in Miami. "What the hell went on here? Was anyone doing anything about it? Just as a national defense thing, how are they able to fly around and no one go after them?''

Even with the transponder silent, the plane should have been visible on radar, both to controllers who handle cross-continent air traffic and to a Federal Aviation Administration command center outside of Washington, according to air traffic controllers.

The FAA, which handles air traffic control, would not discuss the track of Flight 77 or what happened in air-control centers while it was in flight. Neither would American Airlines.

On Thursday, FBI agents were trying to answer those questions, interviewing controllers at the regional Air Route Traffic Control Center in Leesburg, Va.

Flight 77 took off at 8:10 a.m. from Dulles International Airport, and proceeded normally until it got to about the Ohio border, according to Flight Explorer, a company that tracks air traffic for private clients. The transponder went off about 9 a.m., the company said.

At that moment, the flight would have been under the control of the Indianapolis Air Route Traffic Control Center, one of 20 regional centers that track flights between airports.

The trouble should have been instantly noticeable, traffic controllers say.

Flight 77, like other planes, at first showed up on radar screens as a short solid line, with a readout that identifies the plane and gives its altitude and speed. When the transponder shuts down, the short line vanishes. The speed number goes away, too.

"It's just something that catches your eye,'' one controller says.

And it's not that unusual. Transponders fail from time to time; commercial aircraft are required to carry a spare. Although it isn't clear what happened in the case of Flight 77, a controller's first move typically would be to contact the pilot, and tell them the transponder wasn't working.

But even if the plane remained silent, controllers could still find it -- by switching their screen display to the old-fashioned radar that bounces a signal off the plane's metal skin.

Many controllers who track high-flying planes have little experience using that harder-to-read system, one former controller said.

"You'll have controllers with 10 years experience who never track an airplane without a transponder. It just doesn't happen,'' said Ed Freeman, a Maryland consultant who spent 24 years as an air traffic controller.

At about 9:25 a.m., television commentator Barbara Olson called her husband -- Solicitor General Theodore Olson -- and reported that the plane had been hijacked.

Five minutes later, she called back to say the pilot was with the passengers in the back of the plane.

About that time, controllers across the country were frantically trying to get all planes out of the air, ordering all pilots to land at the nearest airport.

Flight 77 was heading directly toward the restricted airspace over the White House when it banked sharply to the right and approached the Pentagon.

Military jets are routinely scrambled in the case of hijackings and "runners,'' planes that do not answer or do not heed air traffic controllers. But FAA officials would not say when controllers detected the errant Flight 77 or whether any fighter jets were able to get into the air to confront it.

Fighter jets are based nearby, in Virginia, and could have reached the White House within minutes, aviation sources say.

In at least one other case, American Flight 11, controllers knew it was a hijacking while it was in the air.

The pilot, who apparently flew the plane much of the way from Boston to New York, pushed a button on the aircraft yoke that allowed controllers to hear what was going on: the hijacker giving orders in a threatening voice, and the pilot trying to be calm, according to an account in the Christian Science Monitor.

Two F-15 jets were scrambled from Otis Air Force Base in New York, the newspaper reported, but the controllers report the plane vanished from the radar just before or after they got in the air. It was the first plane that hit the World Trade Center tower.

Pilots and controllers have instructions on how to handle a typical hijacking.

If the transponder is still working, pilots punch in a four-digit code that tells controllers the plane is being hijacked. Once that signal is received, a controller is supposed to call the aircraft and ask, subtly, if the pilot meant to send the transmission.

The FAA has a detailed hijacking manual: Supervisors are notified. The FAA command center near Washington and the FBI are put on alert. Military jets are scrambled to follow the plane. Air-traffic controllers try to figure out where the hijacker wants to go and, if necessary, clear an air space of other traffic.

The FBI has well-rehearsed plans to send negotiators and hostage rescue teams to airport.

But there's nothing in the security plan that talks about terrorist-flown planes turned into missiles, say experts and former FAA and FBI officials. The plan assumes hijackers want to use the plane to extort something -- not to use it as a suicide bomb.

"I know we thought and talked about it,'' said Robert M. Blitzer, a consultant and former counterterrorism chief at the FBI.

"I just don't know that anyone imagined in reality that something like this would ever happen.''