Experimental Study on the Application of Flat Spin to Vertical Landing of a Fixed-Wing Small UAV

The flat spin of a fixed-wing airplane is usually considered to be dangerous, and should avoided by all means. However, an in descends almost vertically relatively slowly. It can used as means vertical landing, especially for small unmanned aerial vehicle. Controlling the impact speed ground touchdown position necessary realize application flat-spin landing. A large pitch-up moment generated combination all-flying tail gyro precession due yawing motion so-called P-factor propeller rotation was found effective not only rapid entry into spin, but also control pitch attitude rate descent during spin. In this paper, results regarding relationships among deflection angle tail, rotational propeller, rate, obtained flight tests using vehicle are presented fundamental knowledge towards realization practical