Tracking the Flights Hijacked on 9/11


On the morning of Sept. 11, 2001, United Airlines Flights 175 and 93 and American Airlines Flights 77 and 11 were hijacked by terrorists. As the attack unfolded, the flights were frantically tracked by air traffic controllers; the Federal Aviation Administration, or FAA; and the Northeast Air Defense Sector, or NEADS, of the military’s aerospace defense command.

Following are excepts of the staff report on the events prepared for the commission investigating the attacks. To read the full report, go to

American Airlines Flight 11

FAA Awareness

At 8:00 a.m. on Sept. 11, 2001, American Airlines Flight 11 began its takeoff roll at Logan Airport in Boston. A Boeing 767, Flight 11 was bound for Los Angeles with 81 passengers, 11 crew, and 24,000 gallons of jet fuel. By 8:09 a.m., it was being monitored by FAA’s Boston Center (located in New Hampshire). At 8:13 a.m., the controller instructed the flight to “turn twenty degrees right,” which the flight acknowledged. This was the last transmission to which the flight responded.


Sixteen seconds later, the controller instructed the flight to climb to 35,000 feet. When there was no response, the controller repeated the command seconds later, and then tried repeatedly to raise the flight.

At 8:21 a.m., American 11 turned off its transponder, immediately degrading the available information about the aircraft. The controller told his supervisor that he thought something was seriously wrong with the plane....

The controller checked to see if American Airlines could establish communication with American 11. He became even more concerned as its route changed, moving into another sector’s airspace. Controllers immediately began to move aircraft out of its path, and searched from aircraft to aircraft in an effort to have another pilot contact American 11. At 8:24:38, the following transmission came from American 11:

American 11: We have some planes. Just stay quiet, and you’ll be O.K. We are returning to the airport.

The controller only heard something unintelligible; he did not hear the specific words “[w]e have some planes.” Then the next transmission came seconds later:

American 11: Nobody move. Everything will be O.K. If you try to make any moves, you’ll endanger yourself and the airplane. Just stay quiet.

Hearing that, the controller told us he then knew it was a hijacking. The controller alerted his supervisor, who assigned another controller to assist him, and redoubled efforts to ascertain the flight’s altitude. Because the controller didn’t understand the initial transmission, the manager of Boston Center instructed the center’s Quality Assurance specialist to “pull the tape” of the radio transmission, listen to it closely, and report back.

Between 8:25 a.m. and 8:32 a.m., in accordance with the FAA protocol, Boston Center managers started notifying their chain of command that American 11 had been hijacked....

At 8:34 a.m., the Boston Center controller received a third transmission from American 11:

American 11: Nobody move please. We are going back to the airport. Don’t try to make any stupid moves.

Military Notification, Response

Boston Center did not follow the routine protocol in seeking military assistance through the prescribed chain of command. In addition to making notifications within the FAA, Boston Center took the initiative, at 8:34 a.m., to contact the military through the FAA’s Cape Cod facility [in Massachusetts]. They also tried to obtain assistance from a former alert site in Atlantic City, [New Jersey,] unaware it had been phased out. At 8:37:52 a.m., Boston Center reached NEADS. This was the first notification received by the military at any level that American 11 had been hijacked:

FAA: Hi. Boston Center TMU, we have a problem here. We have a hijacked aircraft headed towards New York, and we need you guys to, we need someone to scramble some F-16s or something up there, help us out.

NEADS: Is this real-world or exercise?

FAA: No, this is not an exercise, not a test.

NEADS promptly ordered to battle stations the two F-15 alert aircraft at Otis Air Force Base [on Cape Cod]. At NEADS, the reported hijacking was relayed immediately to Battle Commander Col. Robert Marr. After ordering the Otis fighters to battle stations, Col. Marr phoned Maj. Gen. l Larry Arnold, commanding general of the First Air Force and the Continental Region. Marr sought authorization to scramble the Otis fighters. Maj. Gen. Arnold instructed Marr “to go ahead and scramble the airplanes, and we’d get permission later.” Gen. Arnold then called [North American Aerospace Defense Command, or NORAD,] headquarters to report.

F-15 fighters were ordered scrambled at 8:46 a.m. from Otis Air Force Base.

But NEADS did not know where to send the alert fighter aircraft: “I don’t know where I’m scrambling these guys to. I need a direction, a destination.” ... American 11 impacted the World Trade Center’s North Tower at 8:46:40 a.m.

Shortly after 8:50 a.m., while NEADS personnel were still trying to locate American 11, word reached them that a plane had hit the World Trade Center.

Radar data show the Otis fighters were airborne at 8:53 a.m.. Lacking a target, they were vectored toward military controlled airspace off the Long Island coast.

To avoid New York area air traffic and uncertain about what to do, the fighters were brought down to military air space to “hold as needed.” From 9:08 a.m. to 9:13 a.m., the Otis fighters were in this holding pattern.

United Airlines Flight 175

FAA Awareness

United Airlines Flight 175, a Boeing 767 carrying 65 passengers from Boston to Los Angeles, took off from Logan Airport at 8:14 a.m. At 8:37 a.m. Boston Center polled United 175, along with other aircraft, about whether they had seen an “American 767” (American 11), and United 175’s pilots said they had seen it. The controller turned United 175 away from it as a safety precaution.

At 8:41 a.m., United 175 entered New York Center’s airspace. The controller responsible for United 175 was unfortunately the same controller assigned the job of tracking the hijacked American 11. At 8:47 a.m., at almost the same time American 11 crashed into the North Tower, United 175’s assigned transponder code changed, then changed again. These changes were not noticed for several minutes, because the controller was focused on finding American 11, which had disappeared. At 8:48 a.m., a New York Center manager provided the following report on a Command Center teleconference about American 11, including information that had been relayed by the airline:

Manager, New York Center: OK. This is New York Center. We’re watching the airplane. I also had conversation with American Airlines, and they’ve told us that they believe that one of their stewardesses was stabbed and that there are people in the cockpit that have control of the aircraft, and that’s all the information they have right now.

The New York Center controller and manager were unaware that American 11 had already crashed.

At 8:51 a.m., the controller noticed the change in the transponder reading from United 175. The controller asked United 175 to go back to the proper code. There was no response. Beginning at 8:52 a.m., the controller made repeated attempts to reach the crew of United 175....

The controller spent the next several minutes handing off the other flights on his scope to other controllers and moving aircraft out of the way of the unidentified aircraft (believed to be United 175) as it moved southwest and then turned northeast toward New York City.

At approximately 8:55 a.m., the controller-in-charge notified a New York Center manager that she believed United 175 had also been hijacked. The manager tried to notify the regional managers and was told that the managers were discussing a hijacked aircraft (presumably American 11) and refused to be disturbed. At 8:58 a.m., the New York Center controller searching for United 175 told another New York controller “we might have a hijack over here, two of them.”

Between 9:01 a.m. and 9:02 a.m., a manager from New York Center told the Command Center in Herndon, [Virginia].

Manager, New York Center: We have several situations going on here. It’s escalating big, big time. We need to get the military involved with us. ... We’re, we’re involved with something else, we have other aircraft that may have a similar situation going on here.

The “other aircraft” New York Center referred to was United 175. Evidence indicates that this conversation was the only notice received prior to the second crash by either FAA headquarters or the Herndon Command Center that there was a second hijack. While Command Center was told about this “other aircraft” at 9:01 a.m., New York Center contacted New York terminal approach control and asked for help in locating United 175.

The controllers observed the plane in a rapid descent; the radar data terminated over lower Manhattan. At 9:03:02 a.m., United 175 crashed into the South Tower.

Military Notification, Response

The first indication that the NORAD air defenders had of the second hijacked aircraft, United 175, came in a phone call from New York Center to NEADS at 9:03 a.m. The notice came in at about the time the plane was hitting the South Tower. At 9:08 a.m., the Mission Crew Commander at NEADS learned of the second explosion at the World Trade Center and decided against holding the fighters in military air space away from Manhattan:

Mission Crew Commander, NEADS: This is what I foresee that we probably need to do. We need to talk to FAA. We need to tell ‘em if this stuff is gonna keep on going, we need to take those fighters, put ‘em over Manhattan. That’s best thing, that’s the best play right now. So coordinate with the FAA. Tell ‘em if there’s more out there, which we don’t know, let’s get ‘em over Manhattan. At least we got some kind of play.

The FAA cleared the air space. The Otis fighters were sent to Manhattan. A Combat Air Patrol was established over the city at 9:25 a.m....

NEADS considered scrambling alert fighters from Langley Air Force Base in Virginia to New York, to provide backup. The Langley fighters were placed on battle stations at 9:09 a.m. NORAD had no indication that any other plane had been hijacked.

American Airlines Flight 77

FAA Awareness

American 77 began its takeoff roll from Dulles International Airport [in Virginia] at 8:20 a.m. The flight was handed off routinely from Washington Center to Indianapolis Center at approximately 8:40 a.m.

At 8:54 a.m., American 77 began deviating from its flight plan, first with a slight turn toward the south. Two minutes later it disappeared completely from Indianapolis radar. The controller tracking American 77 told us he first noticed the aircraft turning to the southwest, and then saw the data disappear.... He believed American 77 had experienced serious electrical and/or mechanical failure, and was gone.

Shortly after 9:00 a.m., Indianapolis Center started notifying other agencies that American 77 was missing and had possibly crashed. At 9:08 a.m., Indianapolis Center contacted Air Force Search and Rescue at Langley Air Force Base in Virginia, and told them to look out for a downed aircraft. Indianapolis Center never saw Flight 77 turn around. By the time it reappeared in primary radar coverage, controllers had either stopped looking for the aircraft because they thought it had crashed or were looking toward the west. ... American 77 traveled undetected for 36 minutes on a course heading due east for Washington, D.C.

By 9:25 a.m., FAA’s Herndon Command Center and FAA headquarters knew the following. They knew two aircraft had crashed into the World Trade Center. They knew American 77 was lost. They knew that a hijacker on board American 11 had said “we have some planes,” and concerns over the safety of other aircraft began to mount. A manager at the Herndon Command Center asked FAA headquarters if they wanted to order a “nationwide ground stop.” While executives at FAA headquarters discussed it, the Command Center went ahead and ordered one anyway at 9:25 a.m..

The Command Center kept looking for American 77. At 9:21 a.m., it advised the Dulles terminal control facility, which urged its controllers to look for primary targets. At 9:32 a.m., they found one. Several of the Dulles controllers “observed a primary radar target tracking eastbound at a high rate of speed” and notified Reagan [National] Airport [in Washington]. FAA personnel at both Reagan and Dulles airports notified the Secret Service. Reagan Airport controllers then vectored an unarmed National Guard C-130H cargo aircraft, which had just taken off en route to Minnesota, to identify and follow the suspicious aircraft.

The C-130H pilot spotted it, identified it as a Boeing 757, attempted to follow its path, and at 9:38 a.m., seconds after impact, reported to Washington Tower: “Looks like that aircraft crashed into the Pentagon, sir.”

Military Notification, Response

At the suggestion of the Boston Center’s military liaison, NEADS contacted the FAA’s Washington Center to ask about American 11. In the course of the conversation, a Washington Center manager informed NEADS that “We’re looking ... we also lost American 77.”

The time was 9:34 a.m. This was the first notice to the military that American 77 was missing, and it had come by chance. If NEADS had not placed that call, the NEADS air defenders would have received no information whatsoever that American 77 was even missing, although the FAA had been searching for it. No one at FAA Command Center or headquarters ever asked for military assistance with American 77.

At 9:36 a.m., the FAA’s Boston Center called NEADS and relayed the discovery about the aircraft closing in on Washington, an aircraft that still had not been linked with the missing American 77. The FAA told NEADS: “Latest report. Aircraft VFR [visual flight rules] six miles southeast of the White House. Six, southwest. Six, southwest of the White House, deviating away.”

This startling news prompted the Mission Crew commander at NEADS to take immediate control of the airspace to clear a flight path for the Langley fighters: “OK, we’re going to turn it, crank it up. Run them to the White House.” He then discovered, to his surprise, that the Langley fighters were not headed north toward the Baltimore area as instructed, but east over the ocean. “I don’t care how many windows you break,” he said. “Damn it. OK. Push them back.”

The Langley fighters were heading east, not north, for three reasons. First, unlike a normal scramble order, this order did not include a distance to the target, or the target’s location. Second, a “generic” flight plan incorrectly led the Langley fighters to believe they were ordered to fly due east (090) for 60 miles. The purpose of the generic flight plan was to quickly get the aircraft airborne and out of local airspace. Third, the lead pilot and local FAA controller incorrectly assumed the flight plan instruction to go “090 for 60” was newer guidance that superseded the original scramble order.

After the 9:36 a.m. call to NEADS about the unidentified aircraft a few miles from the White House, the Langley fighters were ordered to Washington, D.C. Controllers at NEADS located an unknown primary radar track, but “it kind of faded” over Washington. The time was 9:38 a.m. The Pentagon had been struck by American 77 at 9:37:46 a.m. The Langley fighters were approximately 150 miles away.

United Airlines Flight 93

FAA Awareness

United 93 took off from Newark [in New Jersey] at 8:42 a.m. It was more than 40 minutes late. At 9:28 a.m., United 93 acknowledged a transmission from the controller. This was the last normal contact the FAA had with United 93.

Less than a minute later, the Cleveland controller and the pilots of aircraft in the vicinity heard “a radio transmission of unintelligible sounds of possible screaming or a struggle from an unknown origin.”

The controller responded, seconds later: “Somebody call Cleveland?” This was followed by a second radio transmission, with sounds of screaming and someone yelling “Get out of here, get out of here!” again from an unknown source. At 9:32 a.m., a third radio transmission came over the frequency: “Keep remaining sitting. We have a bomb on board.” The controller understood, but chose to respond: “Calling Cleveland center, you’re unreadable. Say again, slowly.” He notified his supervisor, who passed the notice up the chain of command. By 9:34 a.m., word of the hijacking had reached FAA headquarters.

Then, at 9:39, a fifth radio transmission came over the radio frequency from United 93:

Ziad Samir Jarrah: Uh, is the captain. Would like you all to remain seated. There is a bomb on board and are going back to the airport, and to have our demands [unintelligible]. Please remain quiet.

The controller responded: “United 93, understand you have a bomb on board. Go ahead.” The flight did not respond. At 9:41 a.m., Cleveland Center lost United 93’s transponder signal. The controller located it on primary radar, matched its position with visual sightings from other aircraft, and tracked the flight as it turned east, then south. About 9:36 a.m., Cleveland Center asked Command Center specifically whether someone had requested the military to launch fighter aircraft to intercept United 93. Cleveland Center offered to contact a nearby military base. Command Center replied that FAA personnel well above them in the chain of command had to make that decision and were working the issue.

From 9:34 a.m. to 10:08 a.m., a Command Center manager updated executives at FAA headquarters on the progress of United 93. During this time, the plane reversed course over Ohio and headed toward Washington.

At 9:42 a.m., Command Center learned from television news reports that a plane had struck the Pentagon. The Command Center’s National Operations manager, Ben Sliney, ordered all FAA facilities to instruct all airborne aircraft to land at the nearest airport. This was a totally unprecedented order. The air traffic control system handled it with great skill, as about 4,500 commercial and general aviation aircraft soon landed without incident.

At 9:46 a.m. and again two minutes later, Command Center updated FAA headquarters that United 93 was now “29 minutes out of Washington, D.C.”

A minute after that, at 9:49 a.m., 13 minutes after getting the question from Cleveland Center about military help, Command Center suggested that someone at headquarters should decide whether to request military assistance.

United 93 crashed in Pennsylvania at 10:03:11 a.m., 125 miles from Washington, D.C. Despite the discussions about military assistance, no one from FAA headquarters requested military assistance regarding United 93. Nor did any manager at FAA headquarters pass any of the information it had about United 93 to the military.

Military Notification, Response

NEADS first received a call about United 93 from the military liaison at Cleveland Center, at 10:07 a.m. Unaware that the aircraft had already crashed, Cleveland passed to NEADS the aircraft’s last known latitude and longitude. NEADS was never able to locate United 93 on radar because it was already in the ground.

At the same time, the NEADS Mission Crew commander was dealing with the arrival of the Langley fighters over Washington, D.C. He was sorting out what their orders were with respect to potential targets. Shortly after 10:10 a.m., and having no knowledge either that United 93 had been heading toward Washington or that it had crashed, the Mission Crew commander explicitly instructed that the Langley fighters did not have “clearance to shoot” aircraft over the nation’s capital.

The news of a reported bomb on board United 93 spread quickly at NEADS. The air defenders searched for United 93’s primary radar return and tried to locate assets to scramble toward the plane. NEADS called Washington Center to report:

NEADS: I also want to give you a heads-up, Washington.

FAA (DC): Go ahead.

NEADS: United nine three, have you got information on that yet?

FAA: Yeah, he’s down.

NEADS: He’s down?

FAA: Yes.

NEADS: When did he land? ‘Cause we have got confirmation.

FAA: He did not land.

NEADS: Oh, he’s down? Down?

FAA: Yes. Somewhere up northeast of Camp David.

NEADS: Northeast of Camp David.

FAA: That’s the last report. They don’t know exactly where.