Three-Surface Model with Redundant Longitudinal Control: Modeling, Trim Optimization and Control in a Preliminary Design Perspective

Notwithstanding the interest in three-surface concept shown by aircraft designers, this configuration was not thoroughly investigated conjunction with adoption of two-elevator surfaces, on both canard and tail. In fact, inclusion an additional elevator produces a redundant longitudinal control which can be specifically exploited to target trim optimization. The same redundancy also employed improve flying qualities aircraft. paper, after introducing simple flight mechanics model, ideal for preliminary design analyses, advantages are explored. Firstly, problem finding deflections tail minimum drag is formulated solved. Secondarily, updating two-surface back-tailed airplane into equivalent one demonstrated, showing potential improvement cruise performance. Finally, controls through smart law achieving better qualities.