Shortly After 10:20 a.m. September 11, 2001: FAA’s Boston Center Declares ‘ATC Zero’

Managers at the FAA’s Boston Center declare “air traffic control zero” (“ATC zero”), which completely shuts down the center’s airspace, after a report is received of a possible airborne threat to their facility. [Federal Aviation Administration, 9/20/2001; Spencer, 2008, pp. 243] The Boston Center in Nashua, New Hampshire, has received a call from the FAA’s New England regional office, informing it that an unidentified aircraft is heading its way. In response, the center’s managers immediately order the evacuation of the facility (see (Shortly After 10:20 a.m.) September 11, 2001). At the same time, they make the declaration of ATC zero. [Spencer, 2008, pp. 243] The declaration of ATC zero means aircraft are not permitted to depart from, arrive at, or travel through the center’s airspace until further notice. [9/11 Commission, 8/26/2004, pp. 24] According to author Lynn Spencer, ATC zero means all the aircraft a center is handling are pushed “onto neighboring sectors, and any new airplanes from adjacent sectors are turned back, at the sector boundaries if necessary.” [Spencer, 2008, pp. 68] Although the exact time the managers declare ATC zero at is unclear, the Boston Center notifies the FAA’s Herndon Command Center of the declaration at 10:35 a.m. At 11:41 a.m., the ATC zero alert at the Boston Center is canceled. [Federal Aviation Administration, 3/21/2002] The FAA’s New York Center declared ATC zero at 9:05 a.m. (see 9:05 a.m. September 11, 2001). [9/11 Commission, 8/26/2004, pp. 24]