Performance and Aeroelastic Tradeoffs on Recent Rotor Blade Designs

Advanced airfoils and blade planforms on recent rotor blade designs have been optimized to improve performance, especially to delay retreating blade stall and to provide low drag to reduce power. There have been several instances, however, where the aeroelastic effects have not been adequately addressed and have caused serious problems which resulted in redesign. This paper will review rotor blade design requirements for hover and forward flight with respect to performance and aeroelasticity. Design parameters for recent rotor blade designs will be presented and problems encountered during flight testing will be discussed.