Nukes vs. Airplanes
Between the F-80 and the F-104, a supersonic pioneer fought the Cold War...in its own way.
- By Jorge and Karen Escalona
- Air & Space magazine, July 2008
(Page 2 of 4)
It fell to Chuck Buzzetti, a research engineer in the flight test organization, to evaluate the strain gauges used to measure the wing loads on the heavy aircraft. “The main I-beam of the F-90 resembled a bridge girder,” says Buzzetti.
Due, in part, to its aluminum skin—four times more stress-resistant than the standard alloy of the day, and a feature that enabled the aircraft to withstand 12 Gs—the single-seat fighter weighed as much as a DC-3, and was almost 71 percent heavier than an F-86, so its Westinghouse engines were seriously underpowered. The team could only hope the airplane would survive its test flight.
“I’ll never forget one flight Tony made on May 17, 1950,” recalls Joiner. “It was one of the times when Kelly [Johnson] was there. The test program was to conduct power-on dives to work up to the so-called sound barrier. We were on the radio with Tony as he made a dive at fairly low altitude. We could see the airplane on the other side of the dry lakebed. It disappeared in the haze. At that moment we heard a tremendous explosion. There is no doubt that both Kelly and I thought that the airplane had augured in. I was afraid that Kelly was going to have a heart attack. Within a very short time Tony called in on the radio. Talk about relief! He had dived the airplane to Mach 1.12 and everything was fine. You have to realize that we hadn’t heard a sonic boom before. I’m not sure about Kelly but there’s a good chance he hadn’t heard one either. Tony went on to exceed the speed of sound a number of times, and the XF-90 handled fine. It certainly experienced no problems structurally.”
Despite the aircraft’s attributes, the need for an all-purpose fighter was declining. “It had become obvious to everyone that this do-everything fighter was not a good idea,” says Joiner. “I guess you could say it was a jack of all trades but master of none.”
In 1950, the Air Force awarded its contract to the McDonnell XF-88A. With the outbreak of the Korean War, however, the Air Force needed combat airplanes in a hurry, and looked to the existing F-80, and the F-86, which was already in production. The exhausted Lockheed team turned to other projects. LeVier would later observe, “Sometimes it is better to chalk an airplane off as experience and go on to something else.”
The company retired the two prototypes to careers as structural test subjects. The first prototype was tested to destruction at the National Advisory Committee for Aeronautics Laboratory in Cleveland. The second XF-90 (along with other aircraft, including a B-45, a B-29, F-47s, and B-17s) was sent to the Nevada Proving Ground for use in a nuclear weapons test. Secured about a half-mile from ground zero, and nose-in to the first two blasts, the XF-90 survived a one-kiloton shot on April 15, 1952, with undamaged wings, but sustained enough dents and cracks—not to mention the buckling of a fuselage fire door—that it would have taken approximately 106 hours to repair. A second, 31-kiloton blast a week later bent the aircraft’s nose. For the third blast, 19 kilotons detonated on May 1, the XF-90 was positioned perpendicular to the shock wave. The blast severed the tail and blew the landing gear from the wing; the main wing structure was buckled and scorched.
The Nevada Test Site later suspended above-ground tests. After a 5.3-kiloton underground blast, in December 1963, the XF-90’s contaminated, cracked, and partially scorched frame was moved to NTS Area 11, where it was used in Broken Arrow exercises in which crews trained for recovery of a downed airplane with a nuclear payload.
The aircraft was officially documented as destroyed— “vaporized, people thought,” says Robert E. Friedrichs, a physical scientist at the National Nuclear Security Administration’s Nevada Site Office. But flying over the test site a few years later, Ernest Joiner saw something unexpected: “Looking down, we could see the XF-90. It appeared to be intact.”