Hiller VZ-1 Pawnee

Last updated
VZ-1 Pawnee
Hiller VZ-1 Pawnee (2).jpg
RoleDirect-lift rotor aircraft
Manufacturer Hiller Aircraft
First flight1955
StatusExperimental
Primary user United States Army
Number built6

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]

Contents

Design and development

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 evaluation

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]

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 & Space Museum. A replica of the 1031 platform is on display at the Evergreen Aviation & Space Museum.

Specifications (Model 1031-A-1)

Data from National Air and Space Museum [6] and Hall-Scott Motor Company [7]

General characteristics

Performance

See also

Aircraft of comparable role, configuration, and era

Related lists

Related Research Articles

A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wing aircraft and other hybrid aircraft with powered rotors such as cyclogyros/cyclocopters and gyrodynes.

<span class="mw-page-title-main">Bell XV-15</span> American experimental tiltrotor aircraft

The Bell XV-15 is an American tiltrotor VTOL aircraft. It was the second successful experimental tiltrotor aircraft and the first to demonstrate the concept's high speed performance relative to conventional helicopters.

<span class="mw-page-title-main">Hiller YH-32 Hornet</span> American ultralight helicopter

The Hiller YH-32 Hornet was an American ultralight helicopter built by Hiller Aircraft in the early 1950s. It was a small and unique design because it was powered by two Hiller 8RJ2B ramjet engines mounted on the rotor blade tips which weigh 13 lb (5.9 kg) each and deliver an equivalent of 45 hp (34 kW) for a total of 90 hp (67 kW). Versions of the HJ-1 Hornet were built for the United States Army and the United States Navy in the early 1950s.

<span class="mw-page-title-main">Avro Canada VZ-9 Avrocar</span> 1959 experimental VTOL aircraft model

The Avro Canada VZ-9 Avrocar was a VTOL aircraft developed by Avro Canada as part of a secret U.S. military project carried out in the early years of the Cold War. The Avrocar intended to exploit the Coandă effect to provide lift and thrust from a single "turborotor" blowing exhaust out of the rim of the disk-shaped aircraft. In the air, it would have resembled a flying saucer.

<span class="mw-page-title-main">Sikorsky R-4</span> Two-seat military helicopter of the 1940s

The Sikorsky R-4 is a two-seat helicopter that was designed by Igor Sikorsky with a single, three-bladed main rotor and powered by a radial engine. The R-4 was the world's first large-scale mass-produced helicopter and the first helicopter used by the United States Army Air Forces, the United States Navy, the United States Coast Guard and the United Kingdom's Royal Air Force and Royal Navy. In U.S. Navy and U.S. Coast Guard service, the helicopter was known as the Sikorsky HNS-1. In British service it was known as the Hoverfly.

<span class="mw-page-title-main">Helicopter</span> Type of rotorcraft in which lift and thrust are supplied by horizontally-spinning rotors

A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing (STOL) or short take-off and vertical landing (STOVL) aircraft cannot perform without a runway.

<span class="mw-page-title-main">Powered lift</span> VTOL capable fixed-wing aircraft

A powered lift aircraft takes off and lands vertically under engine power but uses a fixed wing for horizontal flight. Like helicopters, these aircraft do not need a long runway to take off and land, but they have a speed and performance similar to standard fixed-wing aircraft in combat or other situations.

<span class="mw-page-title-main">Piasecki VZ-8 Airgeep</span> VTOL aircraft prototype by Piasecki Aircraft

The Piasecki VZ-8 Airgeep was a prototype vertical takeoff and landing (VTOL) aircraft developed by Piasecki Aircraft. The Airgeep was developed to fulfill a U.S. Army Transportation Research Command contract for a flying jeep in 1957. The flying jeep was envisioned to be smaller and easier to fly than a helicopter.

<span class="mw-page-title-main">Percival P.74</span> Type of aircraft

The Percival P.74 was a British experimental helicopter designed in the 1950s that was based on the use of tip-jet powered rotors. Although innovative, the tip-rotor concept literally failed to get off the ground in the P.74, doomed by its inadequate power source. Rather than being modified, the P.74 was towed off the airfield and scrapped.

<span class="mw-page-title-main">Doak VZ-4</span> Type of aircraft

The Doak VZ-4 was an American prototype Vertical Takeoff and Landing (VTOL) aircraft built in the 1950s for service in the United States Army. Only a single prototype was built, and the U.S. Army withdrew it from active trials in 1963.

<span class="mw-page-title-main">Doman LZ-5</span> Utility helicopter prototype

The Doman LZ-5 was a utility helicopter developed in the United States in the early 1950s by Doman Helicopters Inc. of Danbury, Connecticut. Despite the procurement of international manufacturing agreements, no series production of the aircraft ever occurred, and only three prototypes were built. Two of these were purchased by the United States Army as the YH-31, but eventually becoming VH-31.

<span class="mw-page-title-main">McCulloch MC-4</span> Type of aircraft

The McCulloch Model MC-4 was an American tandem-rotor helicopter and was the first helicopter developed by McCulloch Aircraft Corporation, a division of McCulloch Motors Corporation. It was evaluated by the United States Army as the YH-30 and the United States Navy as the XHUM-1.

<span class="mw-page-title-main">Piasecki PV-2</span> US helicopter prototype

The Piasecki PV-2 was a helicopter designed by Frank Piasecki. The PV-2 is best known for being one of the first successful helicopters flown in the United States. The PV-2 first flew on April 11, 1943. Developed as a technology demonstrator, the PV-2 brought several new features such as the first dynamically balanced rotor blades, a rigid tail rotor with a tension-torsion pitch change system, and a full cyclic and collective rotor pitch control.

<span class="mw-page-title-main">Kaman K-225</span> American experimental helicopter

The Kaman K-225 is an American experimental helicopter developed by Kaman Aircraft. One example was modified to become the world's first gas turbine-powered helicopter.

<span class="mw-page-title-main">Bell 30</span> Type of aircraft

The Bell 30 was the prototype for the first commercial helicopter, and the first helicopter built by the Bell Aircraft Company. Designed by Arthur M. Young, the type served as a demonstration testbed for the successful Bell 47.

<span class="mw-page-title-main">Curtiss-Wright VZ-7</span> Type of aircraft

The Curtiss-Wright VZ-7 was a VTOL quadrotor helicopter aircraft designed by the Curtiss-Wright company for the US Army. Like the Chrysler VZ-6 and the VZ-8 Airgeep it was to be a "flying jeep".

de Lackner HZ-1 Aerocycle 1954 experimental personal helicopter model by de Lackner Helicopters

The HZ-1 Aerocycle, also known as the YHO-2 and by the manufacturer's designation DH-5 Aerocycle, was an American one-man "personal helicopter" developed by de Lackner Helicopters in the mid-1950s. Intended to be operated by inexperienced pilots with a minimum of 20 minutes of instruction, the HZ-1 was expected to become a standard reconnaissance machine with the United States Army. Although early testing showed that the craft had promise for providing mobility on the atomic battlefield, more extensive evaluation proved that the aircraft was in fact too difficult to control for operation by untrained infantrymen, and after a pair of crashes the project was abandoned. A single model of the craft was put on display.

<span class="mw-page-title-main">Hubschraubermuseum Bückeburg</span> Aviation museum in Bückeburg, Lower Saxony

The Hubschraubermuseum Bückeburg is located in the German town of Bückeburg, 30 miles (50 km) to the west of Hanover. The museum is the sole museum in Germany specialising in rotary-wing flight and one of few worldwide. The museum is dedicated to the history and technology of the helicopter.

<span class="mw-page-title-main">Nagler-Rolz NR 54</span> Austrian experimental backpack helicopter

The Nagler-Rolz NR 54 is an Austrian experimental foldable backpack helicopter developed during World War II. An enlarged variant, the NR 55, was also built.

References

Notes
  1. Rogers 1989, pp. 74–78.
  2. Taylor 1999, p. 104.
  3. Rogers 1989, p. 78.
  4. Winchester 2005, pp. 130–131.
  5. Winchester 2005, p. 130.
  6. 1 2 "Hiller Model 1031-A-1 Flying Platform." Smithsonian National Air and Space Museum. Retrieved: 2 November 2011.
  7. 1955 Hall-Scott Industrial Power Division Annual Report
Bibliography