Beginning at 9:03, a number of United Airlines flight dispatchers send text messages to several United aircraft, indicating to the pilots that planes have flown into the World Trade Center. But, according to the 9/11 Commission, “These messages provided no details or warnings.” [9/11 Commission, 8/26/2004, pp. 36] It is not until 9:21 that United dispatchers are told to warn their flights to secure cockpit doors (see 9:21 a.m. September 11, 2001). [9/11 Commission, 1/27/2004] The dispatcher responsible for Flight 175 and Flight 93—Ed Ballinger—begins sending warning messages to the flights he is monitoring at 9:19 a.m., informing them that two aircraft have hit the WTC (see 9:19 a.m. September 11, 2001). [9/11 Commission, 8/26/2004, pp. 37] Airline dispatchers have an important part to play in managing aircraft in flight. According to commercial pilot and author Lynn Spencer, under FAA rules, dispatchers “take guardianship of each company aircraft in the sky. They are assigned to a certain number of aircraft and know all there is to know about each: who is flying, who is working the cabin, how many pounds of fuel are onboard, the flight plan, the alternate plan, and anything at all relevant to that flight. If there is a glitch in the system, the pilot talks to the dispatcher, and together they formulate a plan of action.” [Spencer, 2008, pp. 35 and 72] United Airlines dispatchers are each responsible for monitoring from ten to 30 flights during a shift, and monitor anything up to two dozen flights at a time. [Longman, 2002, pp. 68]