Berliner-Joyce Helicopter 1925
Henry and his father then decided to build a new, lighter helicopter to improve the thrust-to-weight ratio. Completed in 1925, the new design bore a superficial resemblance to the previous model, but it utilized a more efficient biplane configuration. The lower wing relied on a high angle of incidence and large camber to generate some lift from the rotor downwash. The Berliners also enlarged the rotors and added a novel differential collective pitch control system to replace the ineffective louvers.
However, even with the reduced weight and aerodynamic alterations, the 1925 model showed only a marginal increase in performance over the triplane version. Frustrated, Henry abandoned his helicopter experiments and became disillusioned with the potential of the helicopter. He went on to establish the Berliner Aircraft Company, and played an important role in the development of the innovative Erco Ercoupe.