The Evolution of Helicopter Technology, 1940–1986

Abstract

The evolution of helicopter technology was analysed by means of the characteristics of helicopter models introduced in the period 1940–1986. An improvement took place in some dimensions of performance while others changed little. By analysing the distribution of the models with respect to the technological frontier it was found that the technology could be divided into a core, where the majority of the models are located, and some specialised niches. The core is the region of highest density, relatively far from the frontier, while the niches are generally closer to the frontier and have a low model density. In the core of the technology a dominant design, characterised by two turboshaft engines and one rotor, has emerged, while a greater variety of approaches exists in the niches. The changing model density bctween the core and the niches was related to the different types of competition prevailing in the two regions of characteristics space. The higher density in the core implied a greater similarity of the outputs of different producers and a type of competition moving towards perfect. The relative position of various producing countries was studied. It was found that even amongst the few countries which produce helicopters only two (the USA and the USSR) produce models which are in the niches close to the frontier of the technology.