Icing Aircraft Safety Analysis Based on the Bifurcation Method

Aiming at the problem that icing leads to poor aerodynamic characteristics and affects the safe flight of aircraft . To study how the nonlinear factors contribute to the safety flight ,this paper use NASA's generic transport model(GTM) as an example, this paper establish 4-dimension longitudinal dynamics model and icing effects model, and use the bifurcation theory to analyze the stability of aircraft under different degree of icing, and the maneuverable range of aircraft under corresponding conditions is obtained . It is shown that with the increase of icing degree, the control range of elevator deflection is narrowed, and the possibility of aircraft stall is increasing which brings hidden trouble for flight safety. The evaluation results are consistent with the actual situation, which can provide some reference for the pilot control.