Linear approximations of relations between preliminary design parameters for utility helicopters

Utility helicopters represent an important category of helicopters with evolving design requirements which include the level of emitted noise. The scope of the present work is to contribute towards simplification of both the preliminary design process, and the evaluation of existing helicopters. Noise is included as a design criterion from this early stage of the process. A large number of pairs of design parameters were examined leading to selection of linear approximations between them. The correlations are derived from a created database of current and representative designs which includes noise levels. The relations presented offer simpler and direct estimations of key parameters compared to more elaborate calculation procedures currently employed in the preliminary design.