On 9/11 there were only 14 fighter jets on alert in the contiguous 48 states. No computer network or alarm automatically alerted the North American Air Defense Command (NORAD) of missing planes. "They [civilian Air Traffic Control, or ATC] had to pick up the phone and literally dial us," says Maj. Douglas Martin, public affairs officer for NORAD. Boston Center, one of 22 Federal Aviation Administration (FAA) regional ATC facilities, called NORAD's Northeast Air Defense Sector (NEADS) three times: at 8:37 am EST to inform NEADS that Flight 11 was hijacked; at 9:21 am to inform the agency, mistakenly, that Flight 11 was headed for Washington (the plane had hit the North Tower 35 minutes earlier); and at 9:41 am to (erroneously) identify Delta Air Lines Flight 1989 from Boston as a possible hijacking. The New York ATC called NEADS at 9:03 am to report that United Flight 175 had been hijacked — the same time the plane slammed into the South Tower. Within minutes of that first call from Boston Center, NEADS scrambled two F-15s from Otis Air Force Base in Falmouth, Mass., and three F-16s from Langley Air National Guard Base in Hampton, Va. None of the fighters got anywhere near the pirated planes.
Why couldn't ATC find the hijacked flights? When the hijackers turned off the planes' transponders, which broadcast identifying signals, ATC had to search 4500 identical radar blips crisscrossing some of the country's busiest air corridors. And NORAD's sophisticated radar? It ringed the continent, looking outward for threats, not inward. "It was like a doughnut," Martin says. "There was no coverage in the middle." Pre-9/11, flights originating in the States were not seen as threats and NORAD wasn't prepared to track them.
