Government at all levels shares with the aviation industry the immense responsibility for the 300 million passengers who travel on U.S. airlines each year. Local law enforcement officers involved in civil aviation security programs at over 375 American airports play a vital role in deterrence of criminal threats to air safety and are largely responsible for the success of the antihijacking program. The directory, now in its fifth edition, lists law enforcement organizations participating in aviation security. The availability of this information enables law enforcement personnel to contact their counterparts throughout the country. The list enumerates organizations by State, and includes the District of Columbia and the U.S. territories. Additional pages list FBI resident agents, U.S. Customs Service officials, U.S. Postal Service inspectors, explosives handling units, FAA security officers, detention facilities, and Canadian airport units.