Attempting to crash an aircraft into a building was not an entirely new paradigm. Despite Secretary Rice stating, “I don't think anybody could have predicted that they would try to use an airplane as a missile”, there had been numerous prior attempts to utilize aircraft in this manner. In addition, there had been a significant number of warnings suicide hijackings posed a serious threat. For example, a 1994 report for the Department of Defense predicted every aspect of the 911 attack.
In 1972, hijackers of Southern Airways Flight 49 threatened to crash the airliner into Oak Ridge National Laboratory if a $10 million ransom was not paid. The specific target was the nuclear reactor. The hijacked airliner began a dive toward Oak Ridge, and was only pulled out at the last minute when Southern Airways agreed to pay $2 million to the hijackers.
In 1974, S. Byck attempted to hijack a Delta Airlines DC-9 aircraft to crash it into the White House. During the hijacking, Byck killed a security guard and the copilot before committing suicide after being wounded by police. Also in 1974, Private R. Preston stole an Army helicopter and flew over the White House and hovered for six minutes over the lawn outside the West Wing, raising concerns about a suicide attack.
In 1994, four Algerian terrorists attempted to hijack Air France Flight 8969. The group, identified as Phalange of the Signers in Blood, killed one of the passengers, planted explosives on the plane, and planned to crash the aircraft into the Eiffel Tower. French police stormed the aircraft and stopped the hijacking.
Also in 1994, Flight Engineer A. Calloway boarded Federal Express Flight 705 as an additional jump seat crewmember, intending to overpower the crew and crash the DC-10 aircraft into the Federal Express corporate headquarters in Memphis. Calloway attacked the flight deck crew with a hammer, inflicting serious, permanent, disabling injuries to all three pilots. Additionally in 1994, F. Corder attempted to crash an aircraft into the White House.
The planned 1995 Bojinka attack targeted the Pentagon, an unidentified nuclear power plant, the Transamerica Building in San Francisco, the Sears Tower in Chicago, the World Trade Center, John Hancock Tower in Boston, U.S. Congress, and the White House. In 1996, hijackers attempted to crash Ethiopian Airlines flight 961 into a resort in the Comoros Islands, ditching into the Indian Ocean near the coast.
Another 1996 event occurred when M. Udugov, a Chechen leader, threatened to hijack a Russian airliner and crash it into the Kremlin.
In 1998 the Kaplancilar terrorist organization planned to crash an explosives-laden plane into the tomb of M. Ataturk, Turkey’s founder. The entire Turkish government had gathered at the mausoleum for a ceremony on the day scheduled for the attack. Police foiled the plot and arrested the conspirators shortly before execution of the plan.
In addition to actual aircraft suicide attacks, there were numerous predictions of these types of attacks. One prediction was in the March 2001 pilot episode of the Fox series The Lone Gunmen, featuring a hijacked Boeing 727 used as a missile to crash into the World Trade Center. In 1999, the British Secret Service MI6 provided the U.S. Embassy in London with a secret report on al Qaeda activities. The report indicated al Qaeda was planning to use commercial aircraft to attack the United States. The report stated the aircraft would be used in “unconventional ways”.
The 1993 attack on the World Trade Center prompted an exhaustive threat analysis for the World Trade Center. The study concluded an aerial attack by crashing an aircraft into the Center was a remote possibility requiring consideration. Reports indicated Iran was training pilots to hijack airplanes and fly them into buildings: “Trained aircrews from among the terrorists would crash the airliner into a selected objective”.
A report on terrorist threats prepared for the Federal Research Division of the Library of Congress specifically named bin Laden and al Qaeda: “Suicide bomber(s) belonging to al-Qaida’s Martyrdom Battalion could crash-land an aircraft packed with high explosives (C-4 and semtex) into the Pentagon, the headquarters of the Central Intelligence Agency (CIA), or the White House”. A 1999 keynote address at the National Defense University warned terrorists might attempt to use unmanned aerial vehicles (UAVs) to attack buildings. In 2000, security consultant C. Schnabolk had remarked, the most serious threat to the World Trade Center was someone flying a plane into it.