This investigation studied the aerodynamic performance of an NFL(1)-0414F natural laminar flow airfoil with flap deflection ice accretions and grit roughness.  Four models, each incorporating a different ice protection system, were tested in the NASA Lewis Icing Research Tunnel to acquire inter-cycle ice shapes for each ice protection system and a failure-mode ice shape. Two-dimensional simulations of the failure-mode and inter-cycle ice accretions were created using stereo lithography and tested in the University of Illinois wind tunnel to acquire C_l, C_d, C_m and C_h data. Three spanwise cross-sections of the failure-mode ice shape as well as a LEWICE prediction were tested to evaluate the effect of variations in the ice shape along the span of the model.  Significant differences were found in the aerodynamic performance. Boundary-layer measurements were made through the use of a boundary-layer mouse and the boundary-layer thickness correlated well to the drag values. Lower surface ice roughness aft of the main accretion was modeled and found to have littl measurable aerodynamic effect. All ice accretions tested degraded the aerodynamic performance, but the inter-cycle ice simulations produced larger C_l,max degradation, campaored to the accompanying drag rise, than did the failure-mode ice shapes. Grit roughness of a variety of sizes, area densities, and chordwise extents were applied to the model and the performance measured.  The results of these tests showed that C_l,max decreases with increasing grit size and increasing area density. Little additional decrease occurs for densities over 30%. Drag increases were also seen for increasing grit size. Little performance effect was seen for the various chordwise extents until the roughness covered from 10-30% of the airfoil surface.