A parametric investigation was made to determine which aerodynamic design modifications can be made to improve significantly the performance of light airplanes. The study was made around a typical low wing and a typical high wing airplane. Performance parameters selected for comparison with the baseline configuration are: speed for best range, maximum level speed, specific range, maximum rate of climb, and speed for maximum rate of climb. It is shown that significant improvements in these performance parameters are possible by aerodynamic refinements. It is also shown that by application of modern high lift technology significant improvements in take-off and landing performance can be obtained.A similar analysis was employed to improve stability and handling characteristics such as spiral stability, dutch roll stability, and gust response.By applying a recently developed method of coupling spoilerons into the control system more precise flight path control is achieved during final approach. Several features of the control system are discussed, and computer-generated time histories are presented.