A Performance Analysis of Compound Helicopter Configurations

The compound helicopter is a high speed design concept that is once again being explored due to the new emerging requirements for rotorcraft to obtain speeds that significantly surpass the conventional helicopter. This increase in speed, provided efficient hover capability is maintained, would make the compound helicopter suitable for various roles and missions in both military and civil markets. The paper features two compound helicopters. The first configuration features a coaxial rotor with a pusher propeller providing additional axial thrust, and is referred to as the coaxial compound helicopter. The second configuration, known as the hybrid compound helicopter, features a wing and two propellers providing thrust compounding. In this study, the performance of these two compound helicopter configurations are assessed and compared with a conventional configuration. The paper presents the standard performance parameters of each configuration which include the power required in steady level flight, the maximum range, the maximum endurance and the hover ceiling of each of the aircraft configurations. Furthermore, a performance analysis of each configuration flying standard helicopter missions is conducted.