Development of a Rotorcraft Lifecycle Cost Model Incorporating Reliability and Maintainability with Application to Rotorcraft Preliminary Design

The development work to date of a generalized cost model which integrates operating costs, reliability and maintainability into rotorcraft conceptual design is described. The cost model is combined with a rotorcraft sizing code to predict the flyaway and O&S cost impacts of varying design mission payload and range. For a fixed mission range, scaling an example aircraft from 14 to 18 passengers is shown to have a favorable impact of up to 14% reduction in direct operating cost per available seat-mile. Trends in maintenance costs are explored, suggesting that measures representative of best practice maintenance may reduce total operating costs per available seat-mile by as much as 20% through a combination of reduced cost per maintenance action and reduced aircraft maintenance down time. Reliability is further investigated by using the code to calculate the fleet impact of operational availability requirements on fleet size and fixed annual costs. Future work is suggested in the context of using reliability and maintainability issues to better guide rotorcraft conceptual design.