man who claimed to have a bomb and ordered the plane to land in Cyprus. He surrendered several hours later, after freeing the passengers and crew. Countermeasures As a result of the large number of U.S.–Cuba hijackings in the late 1960s to early 1970s, international airports introduced screening technology such as metal detectors, X-ray machines and explosive detection tools. In the U.S, these rules were enforced starting from January 1973 and were eventually copied around the world. These security measures did make hijacking a "higher-risk proposition" and deter criminals in later decades. Until September 2001, the FAA set and enforced a "layered" system of defense: hijacking intelligence, passenger pre-screening, checkpoint screening and on-board security. The idea was that if one layer were later to fail, another would be able stop a hijacker from boarding a plane. However, the 9/11 Commission found that this layered approach was flawed and unsuitable to prevent the September 11 attacks. The U.S Transportation Security Administration has since strengthened this approach, with a greater emphasis on intelligence sharing. On-board security In the history of hijackings, most incidents involved planes being forced to land at a certain destination with demands. As a result, commercial airliners adopted a "total compliance" rule which taught pilots and cabin crew to comply with the hijackers' demands. Crews advise passengers to sit quietly to increase their chances of survival. The ultimate goal is to land the plane safely and let the security forces handle the situation. The FAA suggested that the longer a hijacking persisted, the more likely it would end peacefully with the hijackers reaching their goal. Although total compliance is still relevant, the events of September 11 changed this paradigm as this technique cannot prevent a murder-suicide hijacking. After the September 11 attacks, it became evident that each hijacking situation needs to be evaluated on a case-by-case basis. Cabin crew, now aware of the severe consequences, have a greater responsibility for maintaining control of their aircraft. Most airlines also give crew members training in self-defense tactics. Ever since the 1970s, crew are taught to be vigilant for suspicious behaviour. For example, passengers who have no carry-on luggage, or are standing next to the cockpit door with fidgety movements. There have been various incidents when crew and passengers intervened to prevent attacks: on December 22, 2001, Richard Reid attempted to ignite explosives on American Airlines Flight 63. In 2009, on Northwest