Electronic Privacy Information Center, 2008); (United States Government Accountability Office, 2007) Another system which was in use since the late 1990s and discontinued after 9/11, was the Threat Image Protection -- TIP system. TSA has also implemented the PMIS or Performance Management Information System which helps to gather and retain information about screening operation of passengers and their luggage. (Electronic Privacy Information Center, 2003) b) Role of various Federal Agencies in Airline Security: After the 9/11 attacks the federal government realized that if airline passengers were to be effectively prescreened, the vital requirements would be the availability of reliable, timely and accurate information about potential terrorists. The "no-fly list" which was used by the airlines to screen passengers prior to 9/11 was supplied by the FBI and as of September 11, 2001, which list contained only 12 names of terror suspects. Other federal agencies involved in intelligence and security possessed lists containing names of thousands of suspected terrorists but these lists were never used to check on passenger lists. Therefore, the federal government consolidated all the lists from various sources into one consolidated watch list and the maintenance of this list was entrusted to FBI's Terrorist Screening Center. The federal government also set up a joint "aviation systems program office" which included many federal agencies like 'NASA', the 'Department of Homeland Security', the 'Department of Defense', the 'Department of Commerce' and the 'FAA'. The functions of this office included promoting interagency cooperation in modernizing the commercial air travel system. (National Research Council (U.S.), et. al. 2003); (United States Government Accountability Office, 2007)

c) Trusted Traveler Programs: The various security screenings at several points before boarding a flight has resulted in extraordinary delays for the passengers apart from incurring huge costs for operating and maintaining such systems. Therefore, the TSA came up with the Registered or Trusted Traveler program which would be permanently implemented across the entire nation. This program would be placed under the jurisdiction of the U.S. Customs and Border Protection or Department of Homeland Security. Under this program, low-risk, international and pre-approved commuter or commercial passengers would be able to go through the security check points at a faster rate without having to go through the otherwise mandatory 100% checking. This would expedite the security process at various airports. Such Trusted Traveler programs in domestic airports would be linked with other international airports so that the transition across international flights becomes smoother. (United States Government Accountability Office, 2007); (Boehmer, 2005)

VI. Future of Air Travel:

Air travel will always remain as the preferred choice of travel for people who want to travel swiftly as well as comfortably. In addition, modern day consumers want their products to be shipped almost overnight. However, various crises like the 9/11 terrorist attacks, closure of the air transportation system after 9/11, the economic downturn, the SARS epidemic, and other events have affected the commercial air travel sector. Security measures have also affected the airline industry with many passengers feeling that the delay resulting from security checks takes the benefit out of air travel. With advanced technologies like virtual reality experiences, videoconferencing and net meetings, many business travelers have opted out of traveling by air and have preferred to carry out business dealings from the comfort of their offices. (Kaplan, 2006); (National Research Council (U.S.), et. al, 2003)

Security concerns have kept many leisure travelers at home following the events of 9/11. However, it has been noticed that such downturns in the civil aviation industry are usually followed by a return to a steady state. Thus, demand for air travel may go up in the future subject to certain constraints. It must be remembered that security issues should be given more priority than capacity concerns. Therefore, the basic challenge for the airline industry would be to develop and implement security-related technologies like BPR or Behavior Pattern Recognition, trace-detection portals, quadrupole resonance scanning and polygraphs, which would enhance security without limiting the capacity or enforcing inordinate delays. (Kaplan, 2006); (National Research Council (U.S.), et. al, 2003)