Henry Adler Berliner (December 13, 1895 – May 1, 1970) was a United States aircraft and helicopter pioneer.
Sixth son of inventor Emile Berliner, he was born in Washington, D.C.. After a short time as aerial photographer with the Army Air Service, in 1919 Henry moved back to Washington to help his father with the helicopter research that had been underway for many years (since 1903 New International Encyclopedia).
Using a Le Rhône engine of 80 hp mounted on a test stand, Henry was able to hover and move forward, but only with assistants holding on to stabilize the contraption. In 1922, he bought a surplus Nieuport 23 fighter's fuselage, added a Bentley 220 hp engine on the front, and connected it by geared shafts to two horizontal rotors mounted on a truss extending sideways from the fuselage. A third horizontal rotor at the rear provided pitch control. This was demonstrated at College Park, Maryland to the U.S. Navy’s Bureau of Aeronautics on June 16, 1922, and is often given (though disputed) as the debut of the helicopter.
In 1923, Henry added a triple set of wings to his prototype, as a backup in case of engine failure. This machine could both hover, and reach forward speeds of 40 mph, but did not have the power to gain much altitude; its best performance, on February 23, 1924, reached an elevation of just 15 feet.
A 1925 biplane-like design was lighter and more efficient, but performed little better and was the Berliners' last experiment. In the following year, Henry founded the Berliner Aircraft Company and went on develop various fixed-wing aircraft. The company merged to form Berliner-Joyce Aircraft in 1929 and was acquired by North American Aviation a few months later; in 1930 Berliner founded Engineering and Research Corporation (ERCO). ERCO built the ERCO Ercoupe
The triplane helicopter was donated to the Smithsonian Institution. A part of the collection at the National Air and Space Museum, it presently is on loan to the College Park Aviation Museum.