9:31 a.m.-9:32 a.m. September 11, 2001: United Airlines, Learning of Potential Problem, Tries to Contact Flight 93

After United Airlines learns that Flight 93 is not responding to air traffic controllers, it notifies its flight dispatchers of this, and two of its employees try to contact the flight. At about 9:30, the FAA’s Cleveland Center informed the United Airlines headquarters, near Chicago, that Flight 93 was not responding to attempted radio contacts (see (9:30 a.m.) September 11, 2001). At 9:31, officials at the headquarters inform the airline’s dispatchers—who are responsible for monitoring aircraft in flight—that there is a potential problem with Flight 93. Over the next minute, United’s air traffic control coordinator and another of its employees each send a text message to Flight 93, stating, “ATC looking for you on 133.37.” Flight 93 does not respond to these or any subsequent text messages. [9/11 Commission, 1/27/2004; 9/11 Commission, 8/26/2004, pp. 39]