This study presents the real-time analysis model for flexible aircraft flight dynamics considering gust effects. As the wing becomes slender, the larger deformation is generated which increases gust responses. To establish the framework for the flexible aircraft analysis, the aerodynamic model considering gust effects is developed using the structure model based on FFRF(Floating Frame of Reference Formulation). Based on this framework, then, the surrogate model is constructed using Neural Network training. The surrogate model enables the real-time analysis of flexible aircraft flight dynamics under the consideration of gust effects.