Mr. Emile Berliner began experimenting with vertical flight aircraft in the early 1900's, with a successful recorded tethered flight around 1909.

He and his son Henry developed one of the first successful helicopters in the early 20's. It was based on a Neiuport 23 fuselage, and utilized two counter-rotating main rotors, one attached to each wing tip.
Reports indicate it could manoeuvre in all directions and could obtain a forward speed of about 40 mph.

The main rotor blades were controlled by differential braking, and later had ailerons on the trailing edge of the main rotor blades to control pitch.

It was successfully demonstrated to the US Army in 1924, with several free flights at College Park, Md. Airport. An example is in storage at the Smithsonian Air & Space Museum's Silver Hill Facility, in Maryland, USA.
Emile was the inventor of the flat phonograph record and founder of the Victor Company - later to become RCA. ~

Henry was the founder of Berliner Aircraft Company, - (later Berliner-Joyce Aircraft Co, which became part of North American Aviation in the early 30's) - and founder of Engineering Research Corporation, Riverdale, Maryland- producer of the Ercoupe.