A numerical model is introduced for studying the gust effect on fighter-bomber aircraft during both the turning and pull-up flights. This model follows the technique proposed by the author for solving the coupled equations of aircraft motion. The general small-disturbance equations of motion, including the gust effect, are obtained as a system of linearized first-order differential equations. These equations are written in the form of a state space equation. The latter equation is integrated by trapezoidal integration, which is stable for various increment sizes. The atmospheric gusts are selected to be of the step type with a duration of five nondimensional time units. It is observed that during manoeuvering flight, turning and/or pull-up flight, a symmetrical disturbance delivers both symmetrical and assymmetrical perturbations. During turning flight, the stable sideslip oscillation of the aircraft during straight flight is replaced by an unstable mode due to side gust exposure. On the other hand, symmetrical unstable modes during straight flight are replaced by stable modes due to downburst effect. Simultaneously the aircraft is futher overloaded by an unstable sideslip mode. It appears that pull-up flight tends to change the aircraft stable modes during straight flight into unstable modes.
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