A systematic study of the effect of simulated ice shape geometry on airfoil aerodynamics was performed. A wind tunnel test was performed using a flapped NLF(l)-0414 airfoil where aerodynamic parameters including hinge moment were measured. The ice shapes tested were designed to simulate a single glaze ice horn with leading-edge radius, size and airfoil surface location varied. In all nine ice simulations were tested at six different leading edge locations. The objective of this research was to determine the sensitivity of iced airfoil aerodynamics to ice shape geometry. Configurations were also tested at three different Reynolds numbers (0.5, 1.0, and 1.8~10~). It was determined that ice horn leading-edge radius had only a small effect on airfoil aerodynamics. However, the aerodynamic performance was very sensitive to ice shape size and location. An almost linear relationship between loss in maximum lift and ice horn location was found with the largest loss at the furthest location back on the upper surface. Reynolds number was found to have little effect on the aerodynamic results on the airfoil with simulated ice shapes.