Handling Qualities of Flexible Aircraft: from Modeling to Pilot-in-the-Loop Assessment

Abstract

Modern passenger aircraft designs are driven by ecological and economical constraints that require the aircraft to become more efficient and reduce their emissions. In order to achieve this, future aircraft designs are often characterized by light structures and high aspect ratios and consequently exhibit an increased aeroelastic flexibility. This increased flexibility can influence the handling qualities of the aircraft. Whereas classical flight dynamics assessments usually assume a rigid-body aircraft model, this assumption is not valid anymore for modern aircraft with increased aeroelastic flexibility. The eigenfrequencies of the structural modes are very low and can interact with the rigid-body dynamics and influence the pilots’ perception and behavior. It is thus essential to include the aeroelastic effects in the aircraft model and consider their influence on the handling qualities. The present paper presents a way to a meaningful handling qualities analysis of a modern flexible passenger aircraft. This includes the model composition and system identification of flight test data, a handling qualities analysis of the developed model as well as the integration of the flexible model in a motion simulator and pilot-in-the-loop handling and PIO and ride qualities evaluations.