Evaluation of the NAWC/AD F/A-18 C/D simulation including database coverage and dynamic data implementation techniques

The NAWC/AD F-18 C/D simulation is capable of modeling in-control and out-of-control flight motions in a very representative manner. While many sources of static and dynamic data were considered during analysis of flight motions vs simulation response, the method of implementing dynamic terms was never rigorously examined. This report examines methods of combining dynamic data (steady wind axis rotary and body axis forced oscillation). The current model's static and dynamic data coverage of the angular and rate excursions experienced during out-of-control motions was evaluated. This revealed that extending static sideslip effects to higher sideslip benefits modeling of some out-of-control maneuvers. When implemented using methodology proposed by Kalviste (1982), properly collected dynamic data are capable of providing adequate dynamic definition. When the simulation was revised to incorporate an entirely as-tested dynamic data set with the Kalviste mechanization, rigorous correlation with flight test revealed a significant improvement in modeling of flight motions over the original model, which used empirically adjusted forced oscillation terms. Further analysis revealed that much of the improvement results from inclusion of the rotary damping terms and that questions persist regarding body axis testing technique and data. (Author)