September 2017

2017 September

Piasecki Aircraft Corporation AirGeep, SeaGeep, & Sky Car
Ducted-fan Flying Jeeps
VZ-8P AirGeep I: September 22, 1958 | PA-59N SeaGeep: November 8, 1961 | VZ-8P (B) AirGeep II: February 15, 1962

In the mid-to-late 1950s and early 1960s, the US Army experimented with individual soldier VTOL mobility concepts that included flying platforms with open rotors or ducted propellers for scout/sniper roles, as well as “flying jeeps” that were capable of carrying a small squad of troops and/or weapons in nap-of-the-earth flight at speeds up to 75 miles/hour (120 km/hr).

Contracts for the design, construction and testing of the flying jeeps were awarded to Chrysler, for the VZ-6, to Curtiss-Wright for the VZ-7, and in July 1957, to Piasecki Aircraft Corp. for their Model 59H AirGeep, which was later designated as the VZ-8P. Initially flown with two Lycoming 180 hp (134 kW) piston engines in September 1958, these were replaced by a single, 425 hp (317 kW) Turbomeca Artouste turboshaft in the VZ-8P AirGeep I. A follow-on version, the VZ-8P (B) AirGeep II, used two, more powerful Artouste turboshafts and was flown in February 1962. The aircraft also featured hydrostatic motor-powered landing gear, permitting ground speeds up to 35 miles/hour (56 km/hr).

The most successful of the three flying jeep concepts, and the only one to be field-tested, the VZ-8P had helicopter-type collective and cyclic controls for the tandem, 3-bladed rigid prop-rotors in the two ducted (shrouded) fans as well as control vanes in the duct slipstream for vertical lift and control. The engines were positioned between the ducts and were offset to counter the weight of the pilot. With a length of 26 ft (7.9 m) and with two 7.5 ft (2.3 m) diameter prop-rotors, the VZ-8P had a normal gross weight of 2,350 lb (1,066 kg). The VZ-8P (B) had a maximum takeoff gross weight of 4,800 lb (2,177 kg), two 8.4 ft (2.5m) diameter prop-rotors and could reach an altitude of nearly 3,000 ft (914m).

The US Navy also got onboard with the concept by testing another variant, the VZ-8N SeaGeep, powered by a single Garrett/AiResearch 480 hp (358 kW) turboshaft. With the addition of two inflatable floats, the aircraft was tested at sea and aboard ship starting in June 1961.

Ultimately the flying jeep concept was not adopted by the Army, and conventional helicopters fulfilled the mission roles originally envisioned for these unique VTOL machines.

Description: Ken Bartie
Photo credits, L-R: PiAC, US Army, NHHS - SDASM Archives, NHHS - SDASM Archives; main photo: Piasecki Aircraft Corp. - PiAC

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