9:21 a.m. September 11, 2001: United Airlines Advises Dispatchers to Issue Warning to Flights

United Airlines issues a companywide order for its flight dispatchers to warn their flights to secure their cockpit doors. [9/11 Commission, 1/27/2004; 9/11 Commission, 7/24/2004, pp. 455] The airline’s air traffic control coordinator sends a message to all of the airline’s dispatchers, telling them: “There may be addnl [additional] hijackings in progress. You may want to advise your flts [flights] to stay on alert and shut down all cockpit access inflt [in flight]. Sandy per Mgmt.” United Airlines dispatchers began notifying their aircraft that planes had crashed into the World Trade Center at 9:03 (see 9:03 a.m. and After September 11, 2001). However, with the exception of one dispatcher (see 9:19 a.m. September 11, 2001), the airline has so far not sent any warnings to its aircraft. [9/11 Commission, 8/26/2004, pp. 36-37] United Airlines did not initially realize the second plane to hit the WTC was one of its own (see Between 9:10 a.m. and 9:20 a.m. September 11, 2001), and it is not until 9:22 that it notifies its dispatchers that UAL Flight 175 has been involved in “an accident” in New York (see 9:22 a.m. September 11, 2001).