A Model for Technological Change Applied to the Turbojet Revolution

During the four decades following the Wright brothers' flight, the combination of propeller and piston engine constituted the normal means of aircraft propulsion. In those years, tremendous progress was made within that system, and, by the adoption of new subsystems, great difficulties were overcome. By the early thirties, the pistonengined airplane still promised, and would deliver, significantly improved performance: it had in no objective sense reached the limits of its development. Thus what seems to be commonly thought the precondition for major technological change-conventional system failure-did not then exist in aeronautics. The men who built the first turbojets responded not to failure but to new scientific insights which implied both future difficulty for the normal system and the possibility of an entirely new system. In the case of the turbojet, scientific advance directly caused radical technological change. This particular technological revolution, which will be explored in detail below, permits hypothesizing a tentative but general interpretation of technological change thought to be especially helpful for the study of recent technology and for understanding the links between science and technology. Before proceeding with the actual history of the shift from propeller and piston engine to turbojet, the details of our model are explained systematically in the first third of our article in order to make explicit our theoretical position. Possibly unfamiliar terms, such as "presumptive anomaly" and "candidate paradigm," are explained and used, and distinctions are made between revolutionary change and its sources and normal developmental change.