American Airlines Flight 77
FAA Awareness. American 77 began deviating from its flight plan at 8:54, with a slight turn toward the south. Two minutes later, it disappeared completely from radar at Indianapolis Center, which was controlling the flight.138
The controller tracking American 77 told us he noticed the aircraft turning to the southwest, and then saw the data disappear. The controller looked for primary radar returns. He searched along the plane’s projected flight path and the airspace to the southwest where it had started to turn. No primary targets appeared. He tried the radios, first calling the aircraft directly, then the air-line. Again there was nothing. At this point, the Indianapolis controller had no knowledge of the situation in New York. He did not know that other aircraft had been hijacked. He believed American 77 had experienced serious electrical or mechanical failure, or both, and was gone.139
Shortly after 9:00, Indianapolis Center started notifying other agencies that American 77 was missing and had possibly crashed. At 9:08, Indianapolis Center asked Air Force Search and Rescue at Langley Air Force Base to look for a downed aircraft. The center also contacted the West Virginia State Police and asked whether any reports of a downed aircraft had been received. At 9:09, it reported the loss of contact to the FAA regional center, which passed this information to FAA headquarters at 9:24.140
By 9:20, Indianapolis Center learned that there were other hijacked aircraft, and began to doubt its initial assumption that American 77 had crashed. A discussion of this concern between the manager at Indianapolis and the Command Center in Herndon prompted it to notify some FAA field facilities that American 77 was lost. By 9:21, the Command Center, some FAA field facilities, and American Airlines had started to search for American 77.They feared it had been hijacked. At 9:25, the Command Center advised FAA headquarters of the situation.141
The failure to find a primary radar return for American 77 led us to investigate this issue further. Radar reconstructions performed after 9/11 reveal that FAA radar equipment tracked the flight from the moment its transponder was turned off at 8:56. But for 8 minutes and 13 seconds, between 8:56 and 9:05, this primary radar information on American 77 was not displayed to controllers at Indianapolis Center.142 The reasons are technical, arising from the way the software processed radar information, as well as from poor primary radar coverage where American 77 was flying.
According to the radar reconstruction, American 77 reemerged as a primary target on Indianapolis Center radar scopes at 9:05, east of its last known posi-tion. The target remained in Indianapolis Center’s airspace for another six minutes, then crossed into the western portion of Washington Center’s airspace at 9:10.As Indianapolis Center continued searching for the aircraft, two managers and the controller responsible for American 77 looked to the west and southwest along the flight’s projected path, not east-where the aircraft was now heading. Managers did not instruct other controllers at Indianapolis Center to turn on their primary radar coverage to join in the search for American 77.143
In sum, Indianapolis Center never saw Flight 77 turn around. By the time it reappeared in primary radar coverage, controllers had either stopped looking for the aircraft because they thought it had crashed or were looking toward the west. Although the Command Center learned Flight 77 was missing, neither it nor FAA headquarters issued an all points bulletin to surrounding centers to search for primary radar targets. American 77 traveled undetected for 36 minutes on a course heading due east for Washington, D.C.144
http://www.9-11commission.gov/report/911Report_Ch1.htm
Most, if not all, centers have discontinued using any primary radar at all. And high altitude sectors never select the function, even if it is available.