The connection between the two flights at Logan International Airport was within Terminal B , but the two gates were not connected within security . Passengers must leave the secured area , go outdoors , cross a covered roadway , and enter another building before going through security once again . There are two separate concourses in Terminal B ; the south concourse is mainly used by US Airways and the north one is mostly used by American Airlines . It had been overlooked that there would still be a security screen to pass in Boston because of this distinct detail of the terminal 's arrangement . At 6:45 am , while at the Boston airport , Atta took a call from Flight 175 hijacker Marwan al-Shehhi . This call was apparently to confirm that the attacks were ready to begin . Atta checked in for American Airlines Flight 11 , passed through security again , and boarded the flight . Atta was seated in business class , in seat 8D . At 7:59 am , the plane departed from Boston , carrying 81 passengers . The hijacking began at 8:14 am — 15 minutes after the flight departed — when beverage service would be starting . At this time , the pilots stopped responding to air traffic control , and the aircraft began deviating from the planned route . At 8:18 am , flight attendants Betty Ong and Madeline Amy Sweeney began making phone calls to American Airlines to report what was happening . Ong provided information about lack of communication with the cockpit , lack of access to the cockpit , and passenger injuries . At 8:24:38 am , a voice believed to be Atta 's was heard by air traffic controllers , saying : " We have some planes . Just stay quiet and you will be OK . We are returning to the airport . " " Nobody move , everything will be OK . If you try to make any moves you 'll endanger yourself and the airplane . Just stay quiet . " " Nobody move , please . We are going back to the airport . Do n't try to make any stupid moves . " The plane 's transponder was turned off at 8:21 am . At 8:46:35 am , Atta flew the plane into the North Tower of the World Trade Center
American Airlines Flight 11
American Airlines Flight 11
Mohamed Atta