For the past 50 years civil air transport has been dominated by the combination of the gas turbine and the B-47 airframe configuration. Both these machines owed their creation to WW2 and both represented revolutionary concepts at the time. Oyer the years, the engine and the airframe have undergone considerable detailed refinement. The changes have resulted in very impressive improvements in performance. However, it is now very clear that both are close to some well defined asymptotic limits that bound their performance. The result is that further potential improvements are smaller in percentage terms, become harder to achieve technically and, consequently, come at increasingly higher cost.

A hugely successful global industry has developed around this standard configuration. Increasingly, more and more companies use aircraft and, as their businesses grow, the demand for aircraft and air transport increases. However, the ability of the environment to absorb this growth is beginning to be questioned and new ideas are required if aviation is to be regarded as an unbounded and a truly sustainable activity.