9:29 a.m. September 11, 2001: Cleveland Air Traffic Controller Thinks Flight 93 Is Hijacked

Shortly after hearing strange noises from the cockpit of Flight 93, Cleveland air traffic controllers notice the plane has descended about 700 feet. John Werth, the controller who is handling the plane, tells the supervisor nearest to him, “I think we have another one [i.e., another hijacking].” He will repeatedly radio the cockpit over the next four minutes, asking the pilot to confirm the hijacking, but receive no response. At 9:30 a.m., Werth begins asking other nearby flights on his frequency if they’ve heard screaming; several say that they have. [Gregor, 12/21/2001 ; 9/11 Commission, 7/24/2004, pp. 28; CBS News, 9/10/2006] The Cleveland Center immediately notifies United Airlines’ headquarters of the loss of communication with Flight 93 (see (9:30 a.m.) September 11, 2001). However, the FAA chain of command is apparently not also immediately informed. And the Cleveland Center will not contact NORAD’s Northeast Air Defense Sector (NEADS) about Flight 93 until 10:07 a.m. (see 10:05 a.m.-10:08 a.m. September 11, 2001). [9/11 Commission, 7/24/2004, pp. 28 and 30]