Results of a preliminary design study to establish the degree of quieting possible in a light helicopter are discussed. The study consists of analytical investigations of noise-reduction measures and of the penalties in performance and mission capabilities. Design data are presented for modified and redesigned versions of the OH-58A Light Observation Helicopter (LOH). The modified version is a test bed for verifying the predicted noise reductions, while the redesignec version shows the extent of changes and increase in weight that are necessary to give an operational LOH the performance and payload of the OH-58A. Predicted noise, performance, and cost of the quiet versions are compared with those of the OH-58A.