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VZ-1 Pawnee

From PlaneSpottingWorld, for aviation fans everywhere
Hiller Flying Platform
Type direct lift rotor aircraft
Manufacturer Hiller Aircraft Corporation
Status Experimental
Primary user United States Army
Number built 6

The Hiller VZ-1 Pawnee (US military designation, earlier Army designation HO-1) was a unique direct lift rotor aircraft, using a counterrotating ducted fan inside a platform that the single pilot stood upon for lift, and controlled by the pilot shifting their body weight around to tilt the platform. The platform was developed starting in 1953 under an Office of Naval Research R&D contract to Hiller Aircraft Corporation, and flew successfully starting in 1955.

Design and development

The original concept had been developed by Charles Horton Zimmerman in the late 1940s. Further elaboration followed, both by Hiller and the De Lackner Company.

There were two main models, the ONR model, and a somewhat larger VZ-1 Pawnee model produced in 1956 for the US Army. Three of each model were built as prototypes. Neither of the variants was put into production.

The smaller models used two engines, each a 44 hp Nelson H-59 engine. The larger models used three of the aforementioned engine and had an extended duct area. The largest variant had ineffective "kinesthetic control" and instead had the operator seated on a platform controlling the flight with conventional helicopter controls.[1]

Testing and evaluation

Due to aerodynamic effects in the duct within which the propellers rotate, the platform was dynamically stable even though the pilot and center of gravity of the platform were fairly high up. In testing, the prototypes flew well enough but the US Army judged them to be impractical as combat vehicles as they were small, limited in speed and only barely flew out of the ground cushion effect.[2]

Two of the six prototypes are known to survive today, one the smaller ONR model at the Hiller Aviation Museum in California, and one VZ-1 Pawnee model at the National Air and Space Museum. This latter craft was formerly on loan to the Pima Air Museum.

Specifications (VZ-1 Pawnee)

General characteristics

  • Crew: one
  • Length: 8 ft 4 in (diameter) (2.5 m)
  • Wingspan: ()
  • Height: 7 ft (2.1 m)
  • Empty weight: 370 lb (167.8 kg)
  • Powerplant: 6× 2 x Nelson H-56 piston engines , 40 hp (30 kW) each



  • standard combat weapons for a US soldier


  1. Winchester 2005, p. 130-131.
  2. Winchester 2005, p. 130.
  • Winchester, Jim. The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters. London: Amber Books Ltd., 2005. ISBN 1-904687-34-2.

External links

See also

Template:US Army flying platforms Template:US Army VTOL

This article is licensed under the GNU Free Documentation License.
It uses material from the Wikipedia article "VZ-1 Pawnee".

This article is licensed under the GNU Free Documentation License.
It uses material from the Wikipedia article "VZ-1 Pawnee".