The Hiller VZ-1 Pawnee (U.S. Army designation; earlier Army designation: HO-1) was a unique direct-lift rotor aircraft, using contra-rotating ducted fans for lift inside a platform upon which the single pilot shifted body weight for directional control. The platform was developed starting in 1953 under an Office of Naval Research (ONR) contract to Hiller Aircraft, and flew successfully beginning in 1955.[1]
The original concept had been developed by Charles H. Zimmerman in the late 1940s.[2] Further development followed, both by Hiller Aircraft and the De Lackner Company. There were two main models, the ONR model 1031-A-1, and the somewhat larger VZ-1 Pawnee model produced in 1956 for the U.S. Army. Three of each model were built as prototypes. Neither of the variants was put into production.[3]
The smaller ONR model used two 44 horsepower (33 kW) Nelson H-59 piston engines, coupled to the propellers by a modified helicopter transmission built by the Industrial Power Division of Hall-Scott. The larger Pawnee model used three of those engines and had an extended duct area. The Pawnee had ineffective "kinesthetic control" and instead had the operator seated on a platform controlling the flight with conventional helicopter controls.[4]
Testing and evaluationedit
Due to aerodynamic effects in the duct within which the propellers rotated, 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, but the U.S. 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.[5]
^ ab"Hiller Model 1031-A-1 Flying Platform." Smithsonian National Air and Space Museum. Retrieved: 2 November 2011.
^1955 Hall-Scott Industrial Power Division Annual Report
Bibliography
Rogers, Mike (1989). VTOL: Military Research Aircraft. New York: Orion. ISBN978-0-517-57684-7.
Taylor, Michael John Haddrick (1999). The World's Strangest Aircraft. London: Grange. ISBN978-0-7607-2102-5.
Winchester, Jim (2005). The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters. London: Amber. ISBN978-1-904687-34-4.
Bradford, Francis H.; Dias, Ric A. (2007). Hall-Scott: The Untold Story of a Great American Engine Maker. Warrendale, PA: SAE International. ISBN978-0-7680-1660-4.
External linksedit
Wikimedia Commons has media related to Hiller VZ-1 Pawnee.
January 01, 1970
hiller, pawnee, army, designation, earlier, army, designation, unique, direct, lift, rotor, aircraft, using, contra, rotating, ducted, fans, lift, inside, platform, upon, which, single, pilot, shifted, body, weight, directional, control, platform, developed, s. The Hiller VZ 1 Pawnee U S Army designation earlier Army designation HO 1 was a unique direct lift rotor aircraft using contra rotating ducted fans for lift inside a platform upon which the single pilot shifted body weight for directional control The platform was developed starting in 1953 under an Office of Naval Research ONR contract to Hiller Aircraft and flew successfully beginning in 1955 1 VZ 1 Pawnee Role Direct lift rotor aircraft Manufacturer Hiller Aircraft First flight 1955 Status Experimental Primary user United States Army Number built 6 Contents 1 Design and development 2 Testing and evaluation 3 Gallery 4 Specifications Model 1031 A 1 5 See also 6 References 7 External linksDesign and development editThe original concept had been developed by Charles H Zimmerman in the late 1940s 2 Further development followed both by Hiller Aircraft and the De Lackner Company There were two main models the ONR model 1031 A 1 and the somewhat larger VZ 1 Pawnee model produced in 1956 for the U S Army Three of each model were built as prototypes Neither of the variants was put into production 3 The smaller ONR model used two 44 horsepower 33 kW Nelson H 59 piston engines coupled to the propellers by a modified helicopter transmission built by the Industrial Power Division of Hall Scott The larger Pawnee model used three of those engines and had an extended duct area The Pawnee had ineffective kinesthetic control and instead had the operator seated on a platform controlling the flight with conventional helicopter controls 4 Testing and evaluation editDue to aerodynamic effects in the duct within which the propellers rotated 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 but the U S 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 5 Two of the six prototypes are known to survive both are ONR 1031 A 1 models One is located at the Hiller Aviation Museum in San Carlos California the other is at the National Air and Space Museum s Udvar Hazy Center in Chantilly Virginia 6 The latter platform was formerly on loan to the Pima Air amp Space Museum A replica of the 1031 platform is on display at the Evergreen Aviation amp Space Museum Gallery edit nbsp Hiller 1031 A 1 at Udvar Hazy Center nbsp Reproduction of the Hiller 1031 Flying Platform built by Ken Spence of Bend Oregon in 2006 nbsp Placard describing the reproduction of the Hiller 1031 on display at the Evergreen Aircraft Museum Specifications Model 1031 A 1 editData from National Air and Space Museum 6 and Hall Scott Motor Company 7 General characteristicsCrew 1 Capacity 185 lb 84 kg payload Diameter 8 ft 4 in 2 54 m Height 7 ft 2 1 m Empty weight 370 lb 168 kg Max takeoff weight 555 lb 252 kg Powerplant 3 Nelson H 59 4 cylinder air cooled horizontally opposed piston engines 40 hp 30 kW each at 4 000 rpm Transmission Hall Scott helicopter variant Main rotor diameter 2 7 ft 2 1 m Main rotor area 76 98 sq ft 7 152 m2 2 contra rotating two bladed aluminum Performance Maximum speed 16 mph 26 km h 14 kn Service ceiling 32 8 ft 10 0 m See also editWilliams X Jet Aircraft of comparable role configuration and era Bensen B 10 De Lackner HZ 1 Aerocycle Related lists List of military aircraft of the United StatesReferences editNotes Rogers 1989 pp 74 78 Taylor 1999 p 104 Rogers 1989 p 78 Winchester 2005 pp 130 131 Winchester 2005 p 130 a b Hiller Model 1031 A 1 Flying Platform Smithsonian National Air and Space Museum Retrieved 2 November 2011 1955 Hall Scott Industrial Power Division Annual Report Bibliography Rogers Mike 1989 VTOL Military Research Aircraft New York Orion ISBN 978 0 517 57684 7 Taylor Michael John Haddrick 1999 The World s Strangest Aircraft London Grange ISBN 978 0 7607 2102 5 Winchester Jim 2005 The World s Worst Aircraft From Pioneering Failures to Multimillion Dollar Disasters London Amber ISBN 978 1 904687 34 4 Bradford Francis H Dias Ric A 2007 Hall Scott The Untold Story of a Great American Engine Maker Warrendale PA SAE International ISBN 978 0 7680 1660 4 External links edit nbsp Wikimedia Commons has media related to Hiller VZ 1 Pawnee Flying Platform article at the Hiller Aviation Museum Retrieved from https en wikipedia org w index php title Hiller VZ 1 Pawnee amp oldid 1204691104, wikipedia, wiki, book, books, library,
