Cost Benefit Evaluation of Helicopter Parasite Drag Reductions

The paper discusses means of evaluating the effect of drag reduction on empty weight, cost to manufacture, and cost to operate. Drag reduction in the design phase is shown to be much more effective than such reduction attempted in the development or product improvement phase. The paper proposes guidelines for determining how much weight and how many dollars can be expended beneficially on drag reduction; A numerical example shows cost and weight evaluation for a simple commercial application.