Airport security
Airport security consists of techniques and methods used in protecting airports from crime and terrorism. Most large airports have their own police force backed up by security guards. In some countries and during wars, paramilitary forces or even soldiers protect airports from internal and external threats.
Large numbers of people pass through an airport every day. Such a large gathering of persons presents in itself a natural target for terrorism due to the number of people crowded into a small area.
Travelers must not be allowed to carry weapons aboard aircraft, so that they cannot carry out an aircraft hijacking. Therefore, travelers must be quickly but efficiently searched. Baggage must be screened to prevent the carrying of bombs aboard an aircraft. X-ray machines are often used to speed this process.
The world's worst failure of airport security was the September 11th attack on the World Trade Center and The Pentagon using hijacked jetliners which killed nearly 3000 people. The second worst failure was the Pan Am Flight 103 bombing over Lockerbie, Scotland in December 1988, killing 270.
Another notable failure was the 1994 bombing of Philippine Airlines Flight 434, which turned out to be a test run for a planned terrorist attack called Operation Bojinka. The explosion was small and killed one person, and so the plane made an emergency landing. Operation Bojinka was discovered and foiled by Manila police in 1995.
Airport security in the United States
Prior to the 1970s American airports had no security arrangements to prevent hijacking. Security measures were introduced following several high profile hijackings starting in the late 1960s. The most notable of these was the attempted simultaneous hijacking in September 1970 by the PLFP of four airliners (of which two were American) and the subsequent destruction of three of them on the ground in Jordan and Egypt.
Sky marshals were introduced in 1970 but there were insufficient to protect every flight and hijackings continued to take place. Consequently in late 1972, the FAA demanded that all airlines begin searching passengers and their carry-on baggage by January 5, 1973. The regulations were tightened up following the Lockerbie bombing with additional checks being made on electrical equipment and strict enforcement of a rule that a passenger's baggage could not be transported on an aircraft unless the passenger also travelled on it. The September 11th attack prompted even tougher regulations, for example increasing the range of items forbidden for passengers to carry onto aircraft and requiring all passengers to prove their identity.
Airport security in the United States is now provided by the Transportation Security Administration of the Department of Homeland Security. Prior to September 11th airport security was provided by security guard companies, often by the lowest bidder due to pressure from airport operators and airlines. It was not uncommon that the lowest-paid employee in the airport was a security guard ([1])