Brian Nagel

An officer at NORAD’s operations center in Cheyenne Mountain, Colorado, calls NORAD’s Northeast Air Defense Sector (NEADS) and asks it to stop “exercise inputs” being sent to the operations center.
NORAD Calls Chief of Exercises at NEADS – The NORAD officer, a “Captain Taylor,” calls NEADS, where the phone is answered by Captain Brian Nagel. [North American Aerospace Defense Command, 9/11/2001] Nagel is chief of NEADS live exercises. [Filson, 2003, pp. 74] After introducing himself, Taylor says, “What we need you to do right now is to terminate all exercise inputs coming into Cheyenne Mountain.” Nagel gives Taylor an extension number and suggests that he call it to get the exercise inputs stopped. Taylor replies, “I’ll do that.” [North American Aerospace Defense Command, 9/11/2001] According to an article in Vanity Fair, “inputs” are simulated scenarios that are put into play for training exercises. [Vanity Fair, 8/1/2006] NORAD has been conducting a major exercise this morning called Vigilant Guardian (see (6:30 a.m.) September 11, 2001). [Arkin, 2005, pp. 545]
Exercise Includes Simulated Radar Information – Taylor is presumably referring specifically to false tracks that have been transmitted onto NORAD radar screens for the exercise. NORAD has the capability to inject simulated material, including mass attacks, into the system during exercises, “as though it was being sensed for the first time by a radar site.” [US Department of Defense, 1/15/1999] All of the operations personnel at NEADS have been instructed to “have their sim switches turned ‘on’” (presumably to allow simulated information to appear on their radar screens) from September 6 until the end of Vigilant Guardian, on September 13. An information page on the exercise stated that a “sim test track will be in place and forward told [i.e. transferred to a higher level of command] to both NORAD and CONR,” NORAD’s Continental United States Region. [Northeast Air Defense Sector, 8/23/2001]
Exercise Supposedly Called Off Earlier – More than 50 members of the battle staff at the NORAD operations center have been participating in Vigilant Guardian this morning. [Airman, 3/2002; 9/11 Commission, 3/1/2004 ] Some accounts will claim this exercise was canceled shortly after 9:03 a.m., when the second World Trade Center tower was hit (see (Shortly After 9:03 a.m.) September 11, 2001). [Airman, 3/2002; Filson, 2003, pp. 59] And a report in the Toronto Star will state, “Any simulated information” for the exercise was “purged from the [radar] screens” at the operations center shortly before the second tower was hit (see (9:00 a.m.) September 11, 2001). [Toronto Star, 12/9/2001] But a member of staff at NEADS complained at 9:30 a.m. about simulated material still appearing on radar screens there, and at 9:34 a.m. the NEADS surveillance technicians were instructed to turn off their “sim switches” (see 9:34 a.m. September 11, 2001). [North American Aerospace Defense Command, 9/11/2001; North American Aerospace Defense Command, 9/11/2001; 9/11 Commission, 2004]