Application of the extended linearization design method to longitudinal flight control

A typical approach to control of a nonlinear system is to linearize the system about a nominal operating point. Then linear feedback design methods are used, yielding a closed-loop system whose linearization about the corresponding closed-loop operating point has the desired characteristics. So long as the closed-loop system is operated in a region sufficiently close to the operating point, the closed-loop linearization should accurately reflect the behavior of the closed-loop nonlinear system. Of course, simulation is used to verify the design effectiveness.