page_title: Quadcopter
section_title: Postwar era
hierarchical_section_title: Quadcopter / History / Postwar era
caption_attribution_description: English: Curtiss-Wright 'Aerial Jeep' VZ-7
context_page_description: A quadcopter or quadrotor is a type of helicopter with four rotors.
  Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity until the arrival of the modern UAV or drone. The small size and low inertia of drones allows use of a particularly simple flight control system, which has greatly increased the practicality of the small quadrotor in this application.
context_section_description: The Convertawings Model A Quadrotor was intended to be the prototype for a line of much larger civil and military helicopters. The design featured two engines driving four rotors through a system of v belts. No tail rotor was needed and control was obtained by varying the thrust between rotors. Flown many times from 1956, this helicopter proved the quadrotor design and it was also the first four-rotor helicopter to demonstrate successful forward flight. Due to a lack of orders for commercial or military versions however, the project was terminated. Convertawings proposed a Model E that would have a maximum weight of 42,000 lb (19 t) with a payload of 10,900 lb (4.9 t) over 300 miles and at up to 173 mph (278 km/h). The Hanson Elastic Articulated (EA) bearingless rotor grew out of work done in the early 1960s at Lockheed California by Thomas F. Hanson, who had previously worked at Convertawings on the quadrotor's rotor design and control system.
  The Curtiss-Wright VZ-7 of 1958 was a VTOL aircraft designed by Curtiss-Wright in competition for the US Army Transport and Research Command "flying jeep". The VZ-7 was controlled by changing the thrust of each of the four ducted fan rotors.
  The Piasecki PA-97 was a propsal for a large hybrid aircraft in which four helicopter fuselages were combined with a lighter-than-air airship in the 1980s.
caption: Curtiss-Wright VZ-7
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