Field methods based on finite difference approximations of the time-do
main Maxwell's equations and the potential-flow equation have been dev
eloped to evaluate the electromagnetic scattering and aerodynamic char
acteristics of airfoils. Strong similarities in the two analysis metho
ds facilitate a synergistic approach to solve the multidisciplinary pr
oblem of airfoil shaping for aerodynamic efficiency and low radar cros
s section (RCS). Results for standard test cases demonstrate that both
methods are quite accurate. A parametric study shows that for frontal
radar illumination, the RCS of an airfoil is independent of the chord
wise location of maximum thickness, but depends strongly on the maximu
m thickness, leading-edge radius, and leading-edge shape. In addition,
the study shows that the RCS of an airfoil can be reduced without sig
nificant effects on its transonic aerodynamic efficiency by reducing t
he leading-edge radius and/or modifying the shape of the leading edge.