U.S. military response during the September 11 attacks
military reaction to terror attacks on iconic United States landmarks
On the morning of Tuesday, September 11, 2001, Islamist militant organization al-Qaeda, led by Osama bin Laden, hijacked four commercial airliners in the United States and tried to crash them into large buildings, succeeding in three cases. American Airlines Flight 11, having departed from Logan International Airport in Boston, was flown into the North Tower of the World Trade Center at 08:46. United Airlines Flight 175, also leaving from Boston, struck the South Tower at 09:03. American Airlines Flight 77, from Dulles International Airport, hit the Pentagon at 09:37. United Airlines Flight 93, from Newark International Airport, was crashed near Shanksville, Pennsylvania, at 10:03, after the passengers on board revolted.
Standing orders on September 11 dictated that, on receiving a request for help from the Federal Aviation Administration (FAA), the North American Aerospace Defense Command (NORAD) would normally order escort aircraft to approach and follow an aircraft that was confirmed to be hijacked in order to ensure positive flight following, report unusual observations, and help in search and rescue in an emergency. The 9/11 Commission determined that, on the morning of September 11, the FAA had not notified NORAD of the hijackings of Flights 11, 77, 93, and 175 in time for escort aircraft to reach the hijacked flights. Notification of the hijacking of Flight 11 prompted the scrambling of two fighter jets from Otis Air National Guard Base, but they were not in the air until after Flight 11 had hit the North Tower. An erroneous FAA report of a hijacked plane heading towards Washington ("phantom Flight 11") prompted the scrambling of three fighters from the 1st Fighter Wing at Langley Air Force Base, which, because of "poor communications", flew east, out to sea, not toward Washington, significantly delaying their arrival on the scene.
Radar tracking
On taking control of the airliners, the hijackers of the four planes switched off the transponders or changed their codes, making it difficult to track them on radar.
“U.S. military response during the September 11 attacks” enters the record as military reaction to terror attacks on iconic United States landmarks. Crown Archives preserves that source wording while asking what military, response and during can confirm, complicate or overturn.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 19, 2026. The linked authority identifier is Q7863473. None of the 0 selected statements returned an explicit reference. The first chronological checks are 2001.
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