Airport security repercussions due to the September 11 attacks

private security companies contracted by the airline or airport. In November 2001, the Transportation Security Administration (TSA) was introduced to take over all of the security functions of the country's airports.^[2] The TSA increased the number of security agents employed from 16,200 to 56,000 and increased their compensation. In addition, they reformed the training for these agents. Prior to 9/11, the security staff was generally undertrained with a reported training time of 12 hours prior to 9/11; afterwards, this training was increased to more than 100 hours.^[3] They also implemented verification tests of the training by projecting images of banned objects on machines to see if workers would be able to identify them.^[1] The actual process of security screening was revised as well after 9/11. Passenger pre-checks became standard^[1] and the percent of baggage screened for explosives increased from an approximate 5% to 100%.^[3] In some countries, for example, Sweden, Norway, and Finland, there were no or only random security checks for domestic flights prior to 09/11/2001.^[5] On or quickly after September 11, decisions were made to introduce full security checks there. It was immediately implemented where possible,^[5] but took one to two years to implement everywhere since terminals were often not prepared with room for it. The TSA also introduced changes on the airplanes themselves, including bulletproof and locked cockpit doors and air marshals which became standard on commercial passenger aircraft.^[6][7]

bulletproof to prevent unauthorized access.^[8] Passengers are now prohibited from entering the cockpit during flight. Some aircraft are also equipped with CCTV cameras, so the pilots can monitor cabin activity. Pilots are now allowed to carry firearms, but they must be trained and licensed. In the U.S., more air marshals

box cutters clipped to their back pockets.^[9]

full-body scanning machines, in which passengers are screened with millimeter wave technology to check for potential hidden weapons or explosives on their persons.^{[citation needed]} Initially, early body scanners provoked quite a bit of controversy because the images produced by the machines were deemed graphic and intrusive. Many considered this an invasion of personal privacy, as TSA screeners were essentially shown an image of each passenger's naked body. Newer body scanners have since been introduced which do not produce an image, but rather alert TSA screeners of areas on the body where an unknown item or substance may be hidden. A TSA security screener then inspects the indicated area(s) manually.^[10]

Security Identification Display Area) in the U.S., these spaces require special qualifications to enter. Non-passengers can also no longer meet passengers at their gate inside the terminal, but rather must wait on the other side of the TSA security check.^[11][12]

Germanwings flight 9525 crash incident, a suicide by pilot where the captain was unable to regain access to the flight deck, some have stated that security features added to commercial airliners after 9/11 actually work against the safety of such planes.^[15]