For your bidding pleasure is this Vintage Aerofoil Shape Copper Tipped Propeller. The twisted aerofoil shape of modern aircraft propellers was pioneered by the Wright brothers. While some earlier engineers had attempted to model air propellers on marine propellers, the Wrights realized that a propeller is essentially the same as a wing, and were able to use data from their earlier wind tunnel experiments on wings. They also introduced a twist along the length of the blades. This was necessary to ensure the angle of attack of the blades was kept relatively constant along their length. The understanding of low speed propeller aerodynamics was fairly complete by the 1920s, but later requirements to handle more power in smaller diameter have made the problem more complex. The condition of this propeller is good, though you can see its age; and has a chip starting to accumulate towards the center of the propeller. The propeller is tipped with sheets of copper . This propeller also has some hardware attached tot he center of the propeller. The measurements of the propeller are 6' x 4". For a complete representation of condition and for additional images please call 800-686-4216. It is the buyer’s responsibility to view each image and preview the item to determine condition.