This paper attempts a view of the development of civil aviation in a rather broad and fundamental way, deliberately avoiding any detailed discussion of the many technical aspects of this large and complex industry.

Anyone who is associated in any way with the design and production of aircraft and with the administration and operation of airlines and airports will be only too well aware of the immensity of the technological and organisational effort involved. And looking back over the past 50 years, the development of civil aviation into a major world industry can be viewed, rightly, as a major technological achievement. However, any technological development and the successful evolution of any transport system or industry must be initiated and sustained by some form of social demand. Frequently the demand is difficult or impossible to identify, indeed the idea of a demand may be less useful than the idea of a welcoming response to supply: technical advance frequentiy seems to generate a new market rather than to satisfy an existing one. Nevertheless aviation has during its development passed through a number of phases and been subject to shifts of objective, sometimes gradual, sometimes very rapid, reflecting changes in the response of individuals, companies, nations, and now perhaps even of the world community at large. These changes in demand may be expressed as changes in priorities and we have tried, in Fig. 1, to give some indication of how the balance of demand appears to have shifted as aviation (in this case, both civil and military aviation) jhas progressed from its early status as a sporting pastime to its present position as a world-wide transport system.