ABSTRACT
Tras study concerns four helicopter airlines operating in the urban regions ofNew York, Chicago, Los Angeles, and San Francisco. It covers the periodfrom 1945 to 1965 when the industry flourished, and the ten years after the ending of subsidies in 1965. The close of the Second World War made available trained pilots, equipment, and financial resources for the inception of helicopter airlines. Subsidies for development were obtained and when these were ended, somewhat prematurely, the subsidized lines reduced their operations or terminated them.
