The American Wil Schuemann pioneered several performance-enhancing modifications to the type, including a re-profiled wing, converting the airfoil to a Wortmann section, various fairings, a new canopy and a reshaped fuselage nose.
The American Wil Schuemann developed several improvements for the type, including a modified wing, converting the airfoil to a Wortmann section, various streamlined components, a new canopy design, and an altered nose section of the fuselage.