| XFV-12 | |
|---|---|
 XFV-12A on a taxiway atPort Columbus International Airport | |
| General information | |
| Type | VTOLfighter |
| Manufacturer | Rockwell International |
| Status | Cancelled (1981) |
| Primary user | United States Navy |
| Number built | 1 |
TheRockwell XFV-12 was a prototype supersonicUnited States Navy fighter which was built in 1977. The XFV-12 design attempted to combine theMach 2 speed andAIM-7 Sparrow armament of theMcDonnell Douglas F-4 Phantom II in aVTOL (vertical takeoff and landing) fighter for the smallSea Control Ship which was under study at the time. On paper, it looked superior to the subsonicHawker Siddeley Harrier attack fighter. However, it was unable to demonstrate an untethered vertical takeoff and its inability to meet performance requirements resulted in the program's termination.
In 1972, the Navy issued arequest for proposals for a next generation supersonic V/STOL fighter/attack aircraft. Rockwell's design with the XFV-12 won againstConvair's proposal with theConvair Model 200.[1] The XFV-12A, despite its concept being considered risky compared to that of the Harrier, was selected for development.[2]
To reduce costs, the nose from theDouglas A-4 Skyhawk and intakes from the F-4 were used. Engine rig testing began in 1974.[3][permanent dead link] Free-flight model tests conducted at theNASA Langley full-scale wind tunnel showed the projected thrust augmentation levels were highly optimistic, and that the aircraft would most likely be incapable of vertical flight on the thrust available, while the design remained suitable for conventional flight.[2]
The XFV-12 used athrust augmented wing concept[3] in which exhaust would be directed through spaces in a wing opened up likevenetian blinds to increase available lift, somewhat like Lockheed's unsuccessfulXV-4 Hummingbird. Such arrangement restricted weapons carriage to under the narrow fuselage and two conformal missile mounts. Itscanards were extremely large, almost 50% of the area of the wings, making it effectively atandem wing. The 30,000 lbf (130 kN)-class afterburningturbofan engine was modified to provide enough thrust to lift the weight of the 20,000 lb (9,072 kg) aircraft. Some of these modifications included closing the rear engine exhaust and redirecting gases through ducts to ejector nozzles in the wings andcanards for vertical lift.
Ground testing of the XFV-12A began in July 1977, and the aircraft was officially rolled out at the Rockwell International facility inColumbus, Ohio on 26 August.[2] Due to increasing costs, construction of the second prototype was abandoned.[2]
Tethered hover tests were conducted in 1978.[2] Over the course of six months, it was determined that the XFV-12A design suffered from major deficiencies with regard to vertical flight, especially a lack of sufficient vertical thrust.[2] Lab tests showed 55% thrust augmentation should be expected; however, differences in the scaled-up system dropped augmentation levels to 19% for the wing and a mere 6% in the canard.[2] While the augmenters did work as expected, the extensive ducting of the propulsion system degraded thrust, and in the end thepower-to-weight ratio was such that the engine was capable of vertically lifting only 75% of the weight of the aircraft in which it was mounted.[2]
Following the tests, and with the program suffering from cost overruns, the Navy decided the XFV-12A was not worth further development, and cancelled the project in 1981.[2] The October 6, 1975 issue ofAviation Week published an article about the Rockwell NA-382 which was an even more ambitious proposal to the Marine Corps to fit a similar wing to theLockheed C-130 Hercules, but the plan never made it off the drawing board.[4]
TheUnited States Marine Corps eventually adopted the subsonic British-designed Harrier, the only truly successfulV/STOL design of the 1960s.
Following program cancellation, the aircraft was disassembled and the cockpit section of the fuselage was stored at NASA'sPlum Brook Station in Sandusky, Ohio. As of May 2012, a group of high school students at theEHOVE Career Center, with guidance from NASA contractor personnel, were to restore the fuselage for use as a museum display.[5][6][needs update]
Data from Jane's All the World's Aircraft 1979–80,[7] Jane's All the World's Aircraft 1980–81[8]
General characteristics
Performance
Armament
Aircraft of comparable role, configuration, and era
Related lists
