A review of the influence of high angle of attack aerodynamics on aircraft dynamic stability

This paper presents a review of the most important flow phenomena associated with flying at high angles of attack, as well as behavior of aerodynamic stability derivatives under such flight conditions. A short note is given of problems encountered by todays fighter aircraft, when flying at a high angle of attack. Discussion of reliable aerodynamic and flight mechanics models is also included. The paper emphasises the fact that, for a correct prediction of aircraft motion at high angle of attack, significant changes in aerodynamic stability derivatives should be taken into consideration. New concepts in combat aircraft design require more attention to be given to the prediction of aircraft dynamic behavior at extreme maneuvers. At the early stages of the developing program, where wind-tunnel results are still not fully available, simple and reliable computational and prediction techniques of non-linear aerodynamic characteristics are required. In some flow regimes, especially for thin wings having sharp leading edges and/or tips the nonlinear Vortex Lattice Method can be recommended as giving load distribution and stability derivatives in good agreement with the experimental results.