From my 2011 dissertation, Evaluating Airline Pilot Attitudes Towards the Transportation Security Administration's Federal Flight Deck Officer Program:

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” (Brush, 2002, para.

24), there had been numerous prior attempts to utilize aircraft in this manner

(CNN, 2001). In addition, there had been a significant number of warnings

suicide hijackings posed a serious threat.

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

(CNN, 2001). Copilot Johnson reported, “The demands at Knoxville were that if

we didn't have the money by 1:00 that we'd crash into the nuclear reactor there”

(CNN Transcripts, 2001, para. 151). The hijacked airliner was placed in a dive

toward Oak Ridge, and was only pulled out of the dive at the last minute when

Southern Airways agreed to pay $2 million to the hijackers (Allison, 2004).

In 1974, S. Byck attempted to hijack a Delta Airlines DC-9 aircraft to

crash it into the White House (Cohen, 2009). 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 (White House Security Review,

n.d.).

Following the 1993 attack on the World Trade Center, Jenkins and

Edwards-Winslow (2003) conducted an exhaustive threat analysis for the World

Trade Center. They concluded that an aerial attack by crashing an aircraft into the

Center was a remote possibility which must be considered. 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” (Bodansky, 1993, p. 15). Senator S. Nunn was concerned terrorists

would attempt to crash a radio-controlled airplane into the Capitol during a State

of the Union address, possibly killing the President, Vice President, and all of

Congress (Nelan, 1995).

In 1994, four Algerian terrorists attempted to hijack Air France Flight

8969 (Air Safety Week, 1995). 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 (Bazerman & Watkins, 2005).

French police stormed the aircraft and stopped the hijacking. R. Yousef, the

architect of the first World Trade Center attack, was associated with these

Algerian terrorists (Lance, 2003).

Another attempted airliner suicide hijacking occurred 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 (CVR Database,

1994). Calloway attacked the flight deck crew with a hammer, inflicting serious,

permanent disabling injuries to all three pilots (Wald, 2001).

On September 11, 1994, F. Corder attempted to crash an aircraft into the

White House (Wald, 2001). Experts had been concerned the White House was

highly vulnerable to an attack from the air (Duffy, 1994). Former CIA director R.

Helms expressed concern a suicidal pilot could easily divert from an approach to

Washington to crash into the White House (Duffy, 1994).

In 1995, FBI informant E. Salem revealed a Sudanese Air Force pilot’s

plot to bomb the Egyptian President’s home and then crash an aircraft into the

U.S. Embassy (Berger, 2004). Salem also testified about Project Bojinka, which,

in addition to the aforementioned bombing of 11 American aircraft, included

crashing an airplane into CIA headquarters. In addition to CIA headquarters, this

second Bojinka wave was planned to target 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 (Brzenzinski, 2001).

McNeil (1996) noted in 1996, Ethiopian Airlines flight 961 was hijacked

and an attempt was made to crash into a resort in the Comoros Islands. At the last

moment, the pilot overpowered the hijacker and ditched the fuel-starved airplane

into the Indian Ocean near the coast. Of the 175 passengers, 123 died (AirSafe

Journal, 2001). Also in 1996, M. Udugov, a Chechen leader, threatened to hijack

a Russian airliner and crash it into the Kremlin (Cohen, 2002).

In 1998, White House Terrorism Chief R. Clarke conducted a training

exercise to simulate a Learjet intentionally crashing into a government building

(Kaplan, 2004). Clarke considered the exercise unsatisfactory (Kaplan, 2002). In

a 1998 briefing to the FAA, three terrorism experts were concerned terrorists

would hijack airliners and crash into buildings in the United States (Fainaru,

2002).

In 1998 the Kaplancilar terrorist organization had planned to crash an

explosives-laden plane into the tomb of M. Ataturk, Turkey’s founder (Anadolu

Agency, 2006). The entire Turkish government was gathered at the mausoleum

for a ceremony on the day scheduled for the attack. The plot was foiled and the

conspirators were arrested shortly before execution of the plan (Anadolu Agency,

2006).

In addition to actual aircraft suicide attacks, there were numerous

predictions of these types of attacks. One such prediction was the script which

showed an airliner crashing into New York in the 1980s movie Escape from New

York (“Kamikaze Jet Hijacking,” n.d.). Another 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 (Killtown, 2009).

In 1999, the British Secret Service MI6 provided the U.S. Embassy in

London with a secret report on al Qaeda activities (Rufford, 2002). 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”

(Rufford, 2006, para. 1).

In a report prepared for the Federal Research Division of the Library of

Congress, Hudson (1999) noted numerous terrorist threats, and 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” (p. 7). A 1999 keynote address at the National

Defense University warned terrorists might attempt to use unmanned aerial

vehicles (UAVs) to attack buildings (Hoffman, 2001). Security consultant C.

Schnabolk had remarked, in 2000, the most serious threat to the World Trade

Center was someone flying a plane into it (Reeves, 2001).