Computer optimization of aircraft handling qualities during preliminary design

The capability to optimize a preliminary aircraft design for handling qualities using one comprehensive tool has been created. The tool has the following capabilities: rapid calculation of stability derivatives and dimensional derivatives, calculation of a longitudinal handling qualities metric, and inherent methodology to optimize a given aircraft configuration for handling qualities, including an intuitive graphical interface. It may be used to analyze both subsonic and supersonic cases, symmetrical and asymmetrical designs, conventional and unconventional configurations. The analysis tool, incorporated into a workstation-based computer code called VORSTAB, uses a graphical 3D model of the configuration, generated using a CAD package. The configuration is then analyzed using a vortex lattice method applicable to both subsonic and supersonic flow. The intuitive graphical interface allows sensitivities to configuration changes to be studied and optimization for handling qualities to be conducted. The VORSTAB tool and optimization scheme were applied to a Lear Jet Model 23 and the North American XB-70.