This paper provides a set of closed form solutions for the lift and drag of wings flying in ground effect both with and without end plates. The developed theories are based on observations of several independent sources of controlled model tests over ground planes and over water and on previous theories prepared by researchers from the original work by Prandtl and Wieselsberger to the present day. The theories developed cover wings of varying aspect ratio, thickness to chord ratios and angle of attack. The results for wings with end plates include the effect of ground (or surface) clearance height, end plate depth and air gap depths beneath the wings or end plates. Good agreement is found between the developed theory and test.
