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

This article presents the results from agility research performed under a grant through the University of Kansas, Several functional agility metrics, including the combat cycle time metric, dynamic speed turn plots, and relative energy state metric, are used to compare turning performance 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 have characteristics similar to the real aircraft, but may not exactly represent the aircraft. The performance comparisons are made using data from optimal test trajectories to reduce sensitivities to different pilot input techniques and to reduce the effects of control system limiters, The turn performance for all three aircraft is calculated for simulated minimum time 180-deg heading captures from simulation data. Comparisons of the three aircraft give more insight into turn performance than would be available from traditional measures of performance, Using the optimal test technique yields significant performance improvements as measured by the metrics. These performance improvements were found without significant increases in turn radius.