Air transport, despite its high profile, still remains more of a potential than a reality. Airfreight accounts for 1 percent of intercity ton-miles. Air transport capability is limited by load size, weight lift capacity, and aircraft availability. Traditionally, intercity airfreight was transported on scheduled passenger flights. While the practice was economical, it resulted in a limited capacity and flexibility of freight operations. The high cost of jet aircraft, coupled with the erratic nature of freight demand, served to limit the economic commitment of dedicated aircraft to all-freight operations.