Aeromechanics Analysis of a Heavy Lift Slowed-Rotor Compound Helicopter

A heavy lift slowed-rotor tandem compound helicopter was designed as a part of the NASA Heavy Lift Rotorcraft Systems Investigation. The vehicle is required to carry 120 passengers over a range of 1200 nautical miles and cruise at 350 knots at an altitude of 30,000 ft. The basic size of the helicopter was determined by the U.S. Army Aeroflightdynamics Directorate’s design code RC. Then performance optimization and loads and stability analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Blade structural design (blade inertial and structural properties) was carried out using the loading condition from CAMRAD II. Performance optimization was conducted to find the optimum twist, collective, tip speed, and taper using the comprehensive analysis. Designs were also developed for alternate missions to explore the influence of the design condition on performance.