Lessons Learned from Modeling & Simulation Use in the Test and Evaluation Process. 55 Years of AFFTC Experience

Fredrick R Webster, United States Air Force Flight Test Center, 412th Test Wing/ ENFA

Abstract

The United States Air Force Flight Test Center ( AFFTC ) has a long history of using modeling and simulation ( M&S ) in the test and evaluation ( T&E ) process. The first documented use of what could be considered modern M&S was in 1954 on the X-2 program. The then new analog simulation was used to define the non-linear inertial coupling characteristics which had earlier led to the loss of the X-2 aircraft. Since then, M&S has been a standard tool at the AFFTC for the flight test of developmental and research aircraft. During the 55 years of M&S use, the AFFTC has learned valuable lessons in the application of M&S to the T&E process. Advancing technology and complex systems integration requirements are resulting in increased M&S use across a broader spectrum of technical disciplines. As M&S use broadens, applying past lessons learned will facilitate the integration of M&S into the overall T&E process.

The specific lessons learned are discussed in three basic categories; understanding the simulation and its limitations, model fidelity and updating, and the multiple uses of M&S across the T&E process. By definition, all simulations are approximations of reality and understanding these limitations will insure that valid results are obtained. All simulations are also bound by the fidelity of the models used. Understanding the implications of model fidelity and the need for model updating from test results is a key factor in using M&S in the T&E process. Finally, the use of M&S in the T&E process is only limited by the ingenuity of the user. Modeling and simulation should be used to benefit multiple disciplines across the technical spectrum.