Performance of Rotary Wing Vehicles

Rotary wing aircraft and especially helicopters are relatively slow machines that normally fly at altitudes below 3000 m. The continual advances in the fields of smart rotor design, lightweight structures and integrated flight management and avionics systems, alongside improvements of the fuselage aerodynamics and the advances recorded in engine efficiency have resulted in an incredible improvement of the performance of modern rotary wing configurations, compared with 20, 30, and 40 years ago. The present chapter reviews specific methods to calculate the helicopter performance and discusses key helicopter performance characteristics. The chapter includes issues related to both “classical performance” (i.e., how fast, how far, how high and with how much payload a rotorcraft can operate) and “environmental performance” (i.e., how easy and how comfortable it is to fly and maintain, how safe is the rotorcraft). Keywords: helicopter; power required; power available; hover capability; autorotation; vertical climb and descent; cruise speed; endurance; range