Short Eros. and Harland Ltd. have carried out a brief preliminary study of the Turbo-Skyvan for crop-spraying and have derived payload data and operating costs on a provisional basis. Further studies have been carried out by the College to assess the Turbo-Skyvan on the basis of economic comparison with typical available aircraft operating on agricultural work and this report deals with the detail of these comparisons. Conclusions are that under European small-field conditions 3 , the Skyvan only becomes competitive when advantage is taken of its versatility to provide a single operator with a number of roles, one of which would be cropspraying, thereby increasing utilisation to more realistic figures (1500 and 2000 hrs/yr. have been investigated, in addition to the average 'crop-spraying only' utilisation of 400 hrsiyr). Under Afro-Asian operating conditions, with larger fields and greater areas ', the above comments are still substantially true but, when the higher utaisations are considered, the Skyvan is cheaper to operate and has a higher application capacity than its assumed competitors.