The Piasecki VZ-8 Airgeep (company designation PA-59) was a prototype

vertical takeoff and landing 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-win ...

(VTOL) aircraft developed by

Piasecki Aircraft The Piasecki Aircraft Corporation (PiAC) is a manufacturer of aircraft, principally advanced rotorcraft. It was founded by American vertical flight pioneer Frank Piasecki to develop compound helicopters and other advanced rotorcraft after he was ...

. 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.

Design and development

Piasecki AIRGEEP II (Army), first flight

To meet the US Army's requirement, Piasecki's design featured two tandem, three-blade ducted rotors, with the crew of two seated between the two rotors. Power was by two

Lycoming O-360-A2A The Lycoming O-360 is a family of four-cylinder, direct-drive, horizontally opposed, air-cooled, piston aircraft engines. Engines in the O-360 series produce between 145 and 225 horsepower (109 to 168 kW), with the basic O-360 produc ...

piston engines, driving the rotors by a central gearbox. The first of two aircraft ordered by the Army, initially designated the Model 59K Skycar (and later renamed Airgeep) by Piasecki and designated VZ-8P by the Army, flew on 22 September 1958.Harding 1998, p.11.PA-59K: ''History - Flying Jeeps''
". ''Piasecki Aircraft Corporation''. 2009. Retrieved 26 March 2010. VZ-8P

It was re-engined with a single Turbomeca Artouste IIB

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaftpower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the exhaust ...

replacing the two piston engines, flying in this form in June 1959. After being loaned to the U.S. Navy for evaluation as the Model 59N where it was fitted with floats, it was returned to the Army and its engine replaced by a lighter and more powerful

Garrett AiResearch TPE331 The Honeywell TPE331 (military designation: T76) is a turboprop engine. It was originally designed in the 1950s by Garrett AiResearch, and produced since 1999 by Honeywell Aerospace. The engine's power output ranges from . Design and developm ...

-6 engine. The second prototype was completed to a modified design, designated Model 59H AirGeep II by Piasecki and VZ-8P (B) by the Army. It was powered by two Artouste engines, with

ejection seat In aircraft, an ejection seat or ejector seat is a system designed to rescue the aircraft pilot, pilot or other aircrew, crew of an aircraft (usually military) in an emergency. In most designs, the seat is propelled out of the aircraft by an ex ...

s for the pilot and co-pilot/gunner and a further three seats for passengers. It was also fitted with a powered tricycle undercarriage to increase mobility on land. The AirGeep II's first flight occurred on 15 February 1962, piloted by "Tommy" Atkins. While the Airgeep would normally operate close to the ground, it was capable of flying to several thousand feet, proving to be stable in flight. Flying low allowed it to evade detection by radar. Despite these qualities, and its superiority over the other two types evaluated by the US Army to meet the same requirement (the Chrysler VZ-6 and the

Curtiss-Wright VZ-7 The Curtiss-Wright VZ-7 (also known as the VZ-7AP) 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". Design and developmen ...

), the Army decided that the "Flying Jeep concept asunsuitable for the modern battlefield", and concentrated on the development of conventional helicopters instead.

Variants

;Model 59K Skycar: Company designation for the first aircraft powered by two )

piston engines, given the military designation VZ-8P Airgeep. Later, the piston engines were replaced by a single ) Turbomeca Artouste IIB turboshaft engine. ;Model 59N SeaGeep I: The first aircraft, (after the piston engines were replaced by a single Artouste), whilst on loan to the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

, fitted with floats. ;PA-59H AirGeep II: The second aircraft, military designation VZ-8P (B), completed with two )

Turbomeca Artouste IIC The Turbomeca Artouste is an early French turboshaft engine, first run in 1947. Originally conceived as an auxiliary power unit (APU), it was soon adapted to aircraft propulsion, and found a niche as a powerplant for turboshaft-driven helicopter ...

turboshaft engines and seats for up to five, including the crew. ;VZ-8P Airgeep I: The military designation of the first aircraft as delivered ;VZ-8P-1 Airgeep I:The first aircraft after the piston engines were replaced by a single Turbomeca Artouste IIB. ;VZ-8P-2 Airgeep I: The first aircraft after the Artouste engine was replaced by a lighter and more powerful )

-6 engine. ;VZ-8P (B) Airgeep II:The military designation of the second aircraft.

Specifications (VZ-8P (B))

References

Notes

Bibliography

*Harding, Stephen. "Flying Jeeps: The US Army's Search for the Ultimate 'Vehicle'". ''

Air Enthusiast ''Air Enthusiast'' was a British, bi-monthly, aviation magazine, published by the Key Publishing group. Initially begun in 1974 as ''Air Enthusiast Quarterly'', the magazine was conceived as a historical adjunct to '' Air International'' maga ...

'', No. 73, January/February 1998. Stamford, Lincs, UK:Key Publishing. . pp. 10–12. *
Piasecki Tests Twin-Turbine and Seagoing VTOLs
// ''Aviation Week & Space Technology'', May 7, 1962, v. 76, no. 19, p. 83.

External links

Piasecki Aircraft Corporation
{{US Army VTOL VZ-8 1950s United States military utility aircraft Cancelled military aircraft projects of the United States Lift fan Ducted fan-powered aircraft Twin-turbine helicopters Aircraft first flown in 1962