EVALUATION OF SEVERAL AGILITY METRICS FOR FIGHTER AIRCRAFT USING OPTIMAL TRAJECTORY ANALYSIS

This article presents the results from agility research performed unde r a grant through the University of Kansas, Several functional agility metrics, including the combat cycle time metric, dynamic speed turn p lots, and relative energy state metric, are used to compare turning pe rformance for generic F-18, X-29, and X-31-type aircraft models. These models are generic because they are 3-degree-of-freedom models that h ave characteristics similar to the real aircraft, but may not exactly represent the aircraft. The performance comparisons are made using dat a from optimal test trajectories to reduce sensitivities to different pilot input techniques and to reduce the effects of control system lim iters, The turn performance for all three aircraft is calculated for s imulated minimum time 180-deg heading captures from simulation data. C omparisons of the three aircraft give more insight into turn performan ce than would be available from traditional measures of performance, U sing the optimal test technique yields significant performance improve ments as measured by the metrics. These performance improvements were found without significant increases in turn radius.