Handling Qualities in Rotorcraft Conceptual Design

This paper presents the development of a rotorcraft conceptual design tool able to incorporate handling qualities assessment at an early design stage. After a first conventional sizing, performed utilizing NASA’s NDARC software, a linearized model of the rotorcraft flight mechanics is built. The linear model is augmented by a simplified control system, designed according to structured H ∞ techniques, to determine augmentation requirements, rather than design the actual flight control system. ADS-33 Bandwidth and Phase-Delay standards are exploited to objectively assess the handling qualities of the current design and to drive an iterative redesign process aimed at enhancing the handling qualities ratings. The rotorcraft parameters resulting from the augmented sizing are subsequently used to automatically generate a real-time capable multibody model, which can be used for the subjective evaluation of its handling qualities via piloted flight simulation. The tool capabilities are demonstrated by designing a conventional lightweight helicopter of the class of the Airbus Helicopters BO105