Henry Berliner, a Washington D.C. native, son of an inventor, and a technical genius in his own right demonstrated a prototype helicopter to the U.S. Navy’s Bureau of Aeronautics in College Park, Maryland.
Berliner was the sixth son of Emile Berliner, and after a brief stint as an aerial photographer with the Army Air Service, moved back to the city of his birth to pursue building a helicopter with his father. Word got around to the Navy, and in the early 1920s, the Berliners were given the opportunity to purchase a Nieuport 23, a World War I French fighter plane, and a British Bentley 220hp engine. The pair worked to perfect the prototype, and in 1922, took it down the road to College Park.
The Berliners had used the fuselage of the Nieuport and the engine in the construction of the aircraft. They used geared shafts to connect the Bentley to two horizontal rotors mounted on a truss extending sideways from the fuselage. A third horizontal rotor at the rear provided pitch control. According to the Smithsonian Air and Space Museum, “To initiate forward flight, the pilot pushed forward on the stick to increase the pitch of the horizontal tail rotor, which dropped the nose and inclined the lifting propellers slightly to initiate forward flight. The flight controls also connected to elevators and an enlarged rudder on the tail of the fuselage, which helped maintain control at higher forward speeds. Two sets of five 91 cm (36 in) x 20 cm (8 in) louvers, located below each rotor, opened and closed differentially to provide roll control by presenting a flat surface, which reacted against the rotor downwash.”
The Berliners took the lessons learned from the flight, and worked to develop another prototype, that they demonstrated for the Navy in February 1924. Though that worked considerably better than the 1922 test, the aircraft was still not completely controllable, and could not gain much height. It would take another 15 years for Igor Sikorsky to build, test, and fly the first true helicopter.