Canada. Transport Canada. Air Navigation System Directorate: As part of its civil aviation activities, Transport Canada has always had responsibilities towards air navigation and air traffic control. When the department was created in 1936, it took over the Civil Aviation Branch of the Department of National Defence, which included early air traffic control infrastructure such as light beacons and radio communications. The responsibility for the construction, maintenance, inspection, and operation of these navigation aids initially fell to the Airways and Airports section of the department's Civil Aviation Division. Over the following decades, the department's air navigation services rapidly grew to keep pace with the growth in commercial air traffic. In 1939, the first air traffic control tower was built at St. Hubert Airport. By 1940, a formal Air Traffic Control service was established within the Airways and Airports section. The Airways and Airports section built, staffed, and operated airport traffic control towers and airway control systems (i.e. communications systems between airports). By 1950, the responsibilities of the Air Traffic Control service also included the provision of information to pilots, such as weather forecasts and traffic information. As a part of a departmental reorganization in 1970, Air Traffic Control became its own Division, under the newly created Canadian Air Transportation Administration (CATA). By the late 1970s, Air Traffic Control started being referred to as the Air Navigation System (ANS). In 1985, CATA was disbanded and split into the Airports Authority Group and the Aviation Group. The ANS Directorate was hence established within the Aviation Group. The ANS Directorate was responsible for ensuring the safe and efficient movement of aircraft by providing: air traffic control in domestic and international airspace; flight information services such as weather briefings for pilots and airport advisory services; air navigation aids; flight calibration, inspection services and aeronautical information; and radar surveillance and communication systems. In addition to the operational duties of the ANS Directorate and its predecessors, Transport Canada was historically involved in training and research related to air traffic control. In 1973, the Transport Canada Training Institute (TCTI) was established to provide training for air traffic controllers, electronics technicians and engineers, meteorological technicians, and flight service specialists. The Air Traffic Services Research and Experimentation Center was formed in 1976 to assist in finding solutions to air traffic control problems and in determining the operational impact of proposed changes to the air navigation system. Organizationally, these areas were outside the ANS Directorate, but they supported the ANS through training and research activities. In the February 1994 budget, Parliament announced it would explore options for the commercialization of the ANS. The Civil Air Navigation Services Commercialization Act (CANSA), which provided the Minister of Transport the authority to execute the sale of ANS assets, was enacted on June 20th, 1996. All ANS assets, including the operational ANS infrastructure, personnel, equipment, the TCTI, and the Air Traffic Services Research and Experimentation Center were sold to a newly created non-profit private corporation, NAV CANADA, on November 1st, 1996.