Investigation and improvement of directional stability and control of a propeller-driven STOL aircraft

The scope of this paper is to investigate and improve the aerodynamic properties of a propeller driven state-of-the-art active high-lift configuration in lateral motion. 3D RANS simulations of the landing configuration with circulation control and slipstream deflection under crosswind, and one engine inoperative (OEI) conditions were performed. The configuration shows directionally unstable behavior at small sideslip angles and high yawing moment production under OEI conditions. Flowfield analyses indicate that both can be attributed to wake-tail interference effects caused by slipstream–vortex interaction. The integration of tail fences at the rear of the fuselage leads to considerable improvements for both conditions.