At the very dawn of the Cold War, the United States Air Force wanted a “penetrating escort” jet that would accompany a strategic bomber like the B-29 and B-50 deep inside Soviet territory. Moreover, this new fighter-bomber jet was envisioned with supersonic speed, a combat radius of 900 to 1,500 miles, and multipurpose missions against ground targets. The result was the Lockheed XF-90, a fighter jet that, though it would ultimately fail to see service, showed its mettle by actually surviving several atomic bomb tests.
The XF-90 was his challenge. Derivatively speaking, the XF-90 was an outcropping of the F-80 Shooting Star, the United States’ first operational jet. The straight wing of the F-80 inherently placed limitations on its high-speed capabilities, so Johnson played with a host of configurations-some 65 in fact he struck gold with the swept wings, which displaced shock waves at high speeds.
The XF-90 design featured a needle nose, 35-degree swept wings, and a vertical stabilizer that could travel back and forth. Powered by side-mounted Westinghouse J34 turbojets, the XF-90 became the first U.S. fighter to employ afterburners, which provided that extra speed when pushed but at a fuel cost. The jet was armed with six 20-millimeter M39 cannons, and wing-tip fuel pods added its range to a projected 2,300 miles.
Its airframe was built out of high-strength 75T aluminum alloy, thus making it as strong as a “bridge girder” itself. This overengineering resulted in one of the biggest and heaviest single-seat fighters of the time, nine tons empty. Its aluminum skin could withstand twelve times the force of gravity, which was a testament to its durability.
Lockheed produced two airframes: 46-687, the standard XF-90, and 46-688, which was designated XF-90A, identical to the baseline aircraft except for an afterburning J34-WE-15 engine. Lockheed test pilot Tony Levier conducted the first flight of the XF-90 on June 3, 1949. However, the J34s were unable to produce sufficient thrust to allow the aircraft to reach its design speed. The takeoff and landing rolls were also excessive. With the afterburners, the XF-90A could reach only a single speed—665 miles per hour, therefore, it was nicknamed “the big-breasted turkey.”
Weight-laden, the XF-90 did fly supersonic fifteen times. It did eventually lose the fly-off competition in August 1950 to the McDonnell Douglas XF-88 Voodoo, which was fitted with the same engines but weighed considerably less. The XF-88 would evolve to be the F-101 Voodoo, a reconnaissance variant that would see extensive action during the Vietnam War.
The XF-90 starred in an even more sensational tale, though, while it was undergoing nuclear tests. In 1952, XF-90 46-687 was sent to the NACA test facility in Cleveland, Ohio, where its stout aluminum frame was tested to failure. The XF-90A had an even worse fate: it was taken to the Nevada test range at Frenchman’s Flat to determine the ability of parked aircraft to survive nuclear strikes.
The B-50 bomber is said to have exploded a 1-kiloton Mark 4 nuclear bomb on April 15, 1952, half a mile away from the XF-90A, and still, the jet emerged alive, taking merely 106 hours of repair. A week later, another test involving a 33-kiloton nuke caused much more damage to the nose. Finally, on May 1, a 19-kiloton bomb nearby ripped off its tail and landing gear while warping its wings. The soiled wreck was subsequently placed in Nevada Area 11 for disposal training.
The XF-90A would have otherwise probably slipped into obscurity had scientist Robert Friedrich not gotten a look at the irradiated wreck when flying overhead in the late 1980s. Some almost 15 years later in 2001, the plane would be taken apart and trucked—hazmat suits and all—to the U.S. Air Force Museum in Dayton, Ohio, where it’s still on display in its nuke-blasted state.
Though the XF-90 did not make for a successful design, it filled the heads of US engineers with priceless experiences in developing jets that are armed with after-burning engines, ejection seats, and Fowler flaps. Behind all those famous jet fighters—say, an F-86 Sabre or an F-16 Falcon—could be a long list of wannabes, like the XF-90, that never saw service but helped to push the envelope. How ironic that after seventy years, one is led to believe that the Air Force has reverted to the old concept of a “Penetrating Counter-Air” fighter as an excuse, concept, or strategy to escort at high speed stealthy yet slow bombers deep inside enemy airspace.