Drag assessment of a high performance aircraft using system identification techniques

Drag characteristics of a high performance fighter aircraft are identified by applying suitable mathematical models and parameter estimation techniques to a combination of dynamic maneuvers. For accurate drag characterization, flight maneuvers were performed at close to idle thrust. Raw flight test data was subjected to flight path reconstruction to ensure consistent and error free data signals. The estimated results were used to validate the wind tunnel predictions and to study the effect of stores and leading edge slats on aircraft drag. Of particular interest was the evaluation of drag at supersonic speeds where pilots experienced diminished aircraft performance.