The expansion of air traffic in the United States continues at a forceful rate and shows no signs of decelleration. The Federal Aviation Agency (F.A.A.) traffic control statistics of Fig. 1 show total yearly operations and their relative growth. The graphs distinguish between the three major airspace users, i.e. the scheduled air carriers, the military activity at F.A.A. controlled airfields, and general aviation. The term ‘general aviation’ combines all non-military and non-scheduled airline operators, such as business fliers and private individuals who operate their own airplanes. In addition to the total trend the most significant aspect to note is the high percentage of general aviation activity and its explosive growth rate.