Charles H. Zimmerman

The 5 Foot Vertical Wind Tunnel was built to study spinning characteristics of aircraft. It was an open throat tunnel capable of a maximum speed of 80 mph. NACA engineer Charles H. Zimmerman designed the tunnel starting in 1928.

Zimmerman worked at Langley Memorial Aeronautical Laboratory in the 1930s on a variety of research topics, including loads,[1][2][3] airfoils,[4][5] and aircraft stability and design.[6][7] During this time, he was also thinking about much more novel aspects of flight, especially how stability might be maintained. He theorized that the natural balancing reflexes of a person could be adequate to control very small flight vehicles, a concept he called "kinesthetic control". He was also interested in aspects that could lead to Vertical/Short Takeoff and Landing aircraft.

Zimmerman's research[4] posited aircraft having flat circular bodies, sans wings, as their lifting surface. In the 1940s, Zimmerman and the Navy began researching this idea, which led to the Vought XF5U, nicknamed the "flying pancake".

In 1953, Hiller Aircraft contracted with the Office of Naval Research to combine several research ideas, including Zimmerman's "kinesthetic" theory, to produce an airworthy "flying platform". The project was classified and conducted at Hiller's Advanced Research Division. In 1954, the prototype model 1031 was delivered. A 1956 Army contract produced the larger VZ-1 Pawnee.

• Wright Brothers Medal in 1956[8]
• Dr. Alexander Klemin Award in 1956 from the American Helicopter Society

• Flying Platform at Hillier Aviation Museum
• Flying Pancakes