The Helio was designed in the late 1940s by Dr. Otto Koppen of the Massachusetts Institute of Technology( MIT) and Dr. Lynn Bollinger from Harvard University. Their goal was to make a safe aircraft. The benefits of that aircraft was a an aircraft that could take off and land in the area the size of a tennis court. The Helio was eventually dubbed “the tennis court airplane. The design comprised the most known high-lift devices into one aircraft.

Those devices included:

• High-lift wing with the same airfoil as the famed P-51 Mustang.

• Handley-Page Leading Edge Slats – fully aerodynamic, requiring no pilot attention.

• All-Flying Tail – Rather than having just an elevator on the back of the tail, the entire rear wing was made a control surface.

• Fowler Flaps – Large “barn door” flaps that deployed aft, then down, comprising 80% of the trailing edge of the wing.

• Interceptor Devices – More commonly known as “spoilers” these devices were coupled with the ailerons to aid in roll control because of the space needed for the Fowler flaps.

• Lycoming Geared Six-Cylinder Engine – The engine included a gear box that allowed the engine to swing a larger diameter propeller which added greatly to thrust and ability take off faster and to provide dynamic braking on landing.

The Helioplane with a chase car.