Abstract: In the paper, a new design method for preliminary parameters is proposed. The analytic models of the optimization design are established acording to the requirements of the flying performance, stability, engine and weight. The optimal preliminary project of design to meet the requirements of criterion for helicopter design is worked out by applying the computer and optimization techniques in the paper. The method is used for the analysis of helicopters for preliminary parameters that are used in practice and for the analysis of sensibility for preliminary parameters, too. The method is shown to be very useful by the example and applicable in the new design of helicopters.

Key words: helicopter, preliminary design, optimization design, CAD