XV-5 Vertifan

XV-5 Vertifan
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Type	VTOL
Manufacturer	Ryan
Designed by	25 May 1964
Status	Retired
Primary users	United States Army NASA
Number built	2

The Ryan XV-5 Vertifan was a jet powered V/STOL experimental aircraft in the 1960s. The U.S. Army commissioned the Ryan VZ-11RY (which was redesignated as the XV-5 in 1962) in 1961, along with the Lockheed VZ-10 Hummingbird (redesignated as the XV-4).

Design

The XV-5 drove 3 fans. Engine gases from two 3,000 lbf (13 kN) thrust J85 turbojets, similar to those used in the F-5 Freedom Fighter, were sent to exit by turning fans. It was much simpler in concept, if not execution, compared to the future F-35 Lightning II which has one fan driven by a driveshaft, balanced by a rotating rear nozzle. There was a large fan in each wing with covers resembling half-garbage can lids which flipped up for vertical flight. The 36 inch (0.9 m) nose fan provided adequate pitch control, but made flying tricky. The fans provided vertical thrust of 16,000 pounds force (71 kN), nearly three times the thrust of the engines alone.

A set of louvered vanes underneath each of the large wing fans could vector the thrust in any direction and provided yaw control. Each jet engine could be controlled for RPM. Wing fan RPM was determined by the output from the J85 engines and fan flow at the fan inlets. Roll control was by differential actuation of the wing-fan exit louvers.

The project performance was moderately subsonic with delta wings somewhat like an A-4 Skyhawk. There was also a fan in the nose, an unusual intake situated above the 2-seat side-by-side cockpit, and a T-tail.

The XV-5A was finished in Army green, while the XV-5B was painted in white NASA colors. The fans did generate as much thrust as was hoped, but the transition was difficult and abrupt. The XV-5 would be one of the last aircraft made by Ryan, which made mainly drones after the mid 1960s.

The XV-5 was one of many dozens of aircraft which attempted to produce a successful vertical takeoff aircraft, but the lift fan system was heavy, and took a lot of internal volume. Only the Hawker Siddeley Harrier would still be operational by the turn of the 21st Century, while technology would make possible the use of a shaft-driven fan in the F-35.

Service

Two 12,500 lb (maximum gross weight) XV-5A were evaluated in late 1966 by 15 test pilots (the "XV-5A Fan Club"). One was destroyed during a presumably unsuccessful official flight demonstration in April 1965. Ads and tests proposed a rescue version which would winch a person into a compartment behind the pilots. The second plane was extensively damaged in 1966 during trials as a rescue aircraft when the dummy was ingested into a wing fan, fatally injuring the pilot, although it was judged that the fan actually still functioned well enough to continue controlled flight. The second plane was rebuilt as the modified XV-5B, with tests continuing until 1971. A XV-5B can be seen at the Fort Rucker Aviation Museum, Alabama.

Specifications (XV-5)

General characteristics

• Crew: 2
• Length: 44 ft (13.40 m)
• Wingspan: 30 ft (9.14 m)
• Height: ()
• Empty weight: 7,000 lb (3,175 kg)
• Powerplant: 2× General Electric J85-GE-5 turbojet, 2,950 lbf (18 kN) each

Performance

• Maximum speed: 400+ mph (644+ km/h)

References

• Why not put lift fans in the wings? Dr. Raymond L. Puffer, Air Force Flight Center historian
• Lift-fan aircraft - Lessons learned from XV-5 flight experience Gerdes, Ronald M. (SYRE; NASA, Ames Research Center, Moffett Field, CA) AIAA-1993-4838 IN:AIAA International Powered Lift Conference, Santa Clara, CA, Dec 1-3, 1993, Technical Papers (A94-16426 02-05), Washington, American Institute of Aeronautics and Astronautics, 1993
• International V/STOL Historical Society XV-5 Page

See also

Comparable aircraft

• XV-4 Hummingbird

Designation sequence

• post-1962: CV-2 - XV-3 - XV-4 - XV-5 - V-6 - CV-7 - XV-8

Related lists

• List of military aircraft of the United States
• List of VTOL aircraft

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "XV-5 Vertifan".