1958 Piasecki AirGeep.
The US Army Transportation Research Command began an investigation into the flying jeeps in 1956, leading to award of contracts for prototypes to Chrysler, Curtiss-Wright, and Piasecki in 1957. The Piasecki flying jeep effort was the most successful of the three.
The flying jeep was envisioned to be smaller and easier to fly than a helicopter. The AirJeep was intentionally called AirGeep to respect Jeep's brand name.
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 piston engines, driving the rotors by a central gearbox.
The first of two aircraft ordered by the Army flew on 22 September 1958. It was soon re-engined with a single 425hp in June 1959.
After being loaned to the U.S. Navy for evaluation where it was fitted with floats, it was returned to the Army and its engine replaced by a lighter and more powerful 550hp engine.
The second prototype was completed to a modified design. It was powered by two Artouste engines, with ejection seats 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. A larger, more powerful version called the Airgeep-2 was developed in 1962, and it proved even more capable.
Although the Airgeep was intended to operate within a few meters off the ground it was also capable of flying at altitudes of several thousand meters. The Airgeep was a very stable weapons platform and could hover or fly around most any obstacle.
Flying low allowed it to evade detection by radar.
Despite these qualities, and its superiority over the other two types of airjeeps from Piasetsky's competitors, the Army decided that the "Flying Jeep concept [was] unsuitable for the modern battlefield", and concentrated on the development of conventional helicopters instead. The AirGeep project was closed in the early 1960s.
The Piasecki AirGeep technical characteristics.
Crew: 2 (pilot and co-pilot/gunner).
Capacity: up to 3 passengers.
Empty weight: 1184kg; gross weight: 1665kg.
Engines: 2×550hp.
Main rotor diameter: 2×2.5m.