Recordings reveal hijack confusion

Flight 11 was the first plane to crash into the towers

New details of the 11 September hijackings in the United States have emerged in transcripts obtained by the New York Times newspaper.

They reveal how air traffic controllers and other officials came to realise that multiple hijackings were under way.

One of the hijackers who seized American Airlines Flight 11 over New York told passengers: "We have some planes. Just stay quiet and you'll be OK," according to the transcripts.

We are going back to the airport. Don't make any stupid moves

Hijacker

The hijacker's words were picked up by air traffic controllers on a frequency reserved for conversations between planes and controllers. Either the man thought he was talking over the plane's tannoy or one of the crew had activated the radio microphone, the newspaper reported.

The hijacker is reported to have falsely reassured passengers: "We are going back to the airport. Don't make any stupid moves," minutes before the plane crashed into the World Trade Center.

Ironically, one of the first signs that something was wrong came from the doomed United Airlines Flight 175 from Boston to Los Angeles.

Responding to an appeal for help from controllers in finding Flight 11, the pilot of Flight 175 said: "We heard a suspicious transmission on our departure from BOS," the transcript reveals.

The pilot continued: "Sounds like someone keyed the mike and said 'everyone stay in your seats'."

A minute and a half later, communication was lost between controllers and Flight 175.

Doomed plane warned

Flight 11 was the first of the two planes to slam into the World Trade Center, at 0845 local time (1245 GMT), killing everyone on board.

Five minutes after it struck the north tower, the newspaper says, an unidentified pilot was heard to ask over a common frequency: "Anybody know what that smoke is in Lower Manhattan?"

Forty-four passengers and crew died when Flight 93 crashed into a field in Pennsylvania

Eighteen minutes after the first crash, Flight 175 ploughed into the Trade Center's south tower.

The transcripts also reveal how people on the fourth plane to be hijacked - United Airline Flight 93, from Newark to San Francisco - learned of the earlier hijackings during their ill-fated flight.

According to the Times, a dispatcher at United Airlines operations centre near Chicago's O'Hare International Airport, who had been monitoring Flight 175, sent a text message to more than a dozen planes warning them: "Beware, cockpit intrusion."

The Times says that according to a source who has heard recordings of conversations between controllers and the cockpit of Flight 93 confiscated by the FBI, "a very noisy sound of a confrontation was heard on the frequency, very garbled, but with some discernable phrase like, 'Hey, get out of here'".

Passengers on board Flight 93 are believed to have tackled the hijackers and brought the plane crashing down into a field in western Pennsylvania before it could reach its final, unknown destination.