I. Introduction

Applications of system identification methodology to flight vehicles have been too numerous to count. This is evident from the plethora of applications reported in the literature, both in terms of sheer number of aircraft configurations being analyzed and also in terms of modeling complexity. A representative summary of such applications is found in the special focus issue on Flight Vehicle System Identification Engineering Utility of the AIAA Journal of Aircraft.1 References 2 6 provide a consolidated account of activities related to aircraft parameter estimation from flight data. Common to most of these advanced applications is the time-domain methodology of system identification, which we discussed in Chapters 4 8. In those chapters, we also applied them to typical problems to bring out the underlying mathematics, computational details, practical issues, and scope of applicability. Simulated data as well as flight data were analyzed using the software described in the respective chapters. Both the data and software are supplemented to the book. These estimation techniques, either directly or in a suitably modified form, were applied to unstable aircraft in Chapter 9. In general, aerodynamic modeling aspects as well as those pertaining to the data compatibility check using flight path reconstruction techniques were discussed.

In the present chapter we focus on a few more advanced and comprehensive applications than those reported in the preceding chapters. Specifically, we address the following aspects: 1) modeling of transit time lag effect resulting from angle of attack or direct lift flap, or speed brakes and thrust variations, 2)...