Analysis of aircraft dynamics near the flight envelope boundary

A multiple-linear model and high resolution switching scheme are presented to approximate the highly complex and nonlinear behavior of aircraft operating near and within their upset region. The experimental NASA Generic Transport Model (GTM) is utilized in conjunction with Matlab, Simulink, and FlightGear 3D flight simulator software to explore the nonlinear behavior of aircraft during fault scenarios and to create multiple-linear models of the system dynamics through the course of a fault trajectory. It is shown that a switching multiple-linear model system can be used to faithfully recreate the dynamics observed in the nonlinear simulation. Linear analysis techniques are also employed to explore the controllability of the system at various points throughout the fault scenario and to illustrate the usefulness of the multi-linear model.