In-flight ice accretion is an important safety consideration for modern aircraft. The certification of commercial airliners for flight into known icing is difficult due to the expense and challenge in finding the desired icing conditions in flight. The large size of commercial aircraft relative to existing icing wind tunnels and lack of robust scaling methods also makes ice accretion wind tunnel testing difficult. Hybrid or truncated airfoil models use full-scale leading edges with redesigned aft sections to provide test articles with much reduced model chord and therefore tunnel blockage allowing effectively full-scale icing testing on very large wings. This thesis presents research focused on understanding the accuracy of hybrid designed models applied to the design of models for swept wing commercial airliners. Research was performed examing the effect of the hybrid scale factor, extent of the full-scale leading edge, application of flap, wind tunnel walls, and variation of icing conditions. Hybrid designs were found to be dependent on the design angle of attack and ice accretion parameter, but they did provide an accurate ice shape. While limits to the flap effectiveness exist, flaps can be used to match ice shapes for off-design cases at low and moderate angles of attack. The tunnel wall analysis shows that there are some aerodynamics effects due to the wind tunnel walls, but the droplet impingement remained similar, implying that the hybrid design is not highly dependent on tunnel walls for wind tunnel height to airfoil chord (h/c) ratios greater than two.