United Airlines orders its aircraft that have not yet taken off to remain on the ground. However, the exact time and details of this order are unclear. According to the 9/11 Commission, United orders the “ground stop” at an unstated time after about 9:10, when American Airlines had ordered a nationwide ground stop of its aircraft (see Between 9:00 a.m. and 9:10 a.m. September 11, 2001). [9/11 Commission, 7/24/2004, pp. 10] The Wall Street Journal reports that Andy Studdert, United Airlines’ chief operating officer, gives the order for United aircraft to remain “frozen on the ground” at 9:20. However, it only describes this order applying to “all international flights,” so whether it also applies to United’s domestic flights is unclear. [Wall Street Journal, 10/15/2001] The FAA will issue an order to all its facilities, initiating a “national ground stop,” at around 9:25 a.m. (see (9:26 a.m.) September 11, 2001). [Time, 9/14/2001] At around 9:45, United Airlines will order all its airborne flights to land (see (9:45 a.m.) September 11, 2001). [9/11 Commission, 1/27/2004]