In the 1950s, the Mach 2+ B-58 Hustler seemed a safe bet to win the arms race.
- By Dale Smith
- Air & Space magazine, January 2006
NASM (SI Neg. #6569)
THE DESIGN OF U.S. FRONTLINE FIGHTERS and bombers—the F-117, F-22, and B-2—is primarily based on a simple defensive strategy: If they can’t see you, they can’t shoot at you. But way back when radar was young and stealth technology was a far-off dream, the Air Force bet on a different strategy: They may see you, but they sure won’t catch you. In the 1960s, the Air Force relied on speed to penetrate enemy airspace, and the airplanes built to be uncatchable were as radical in their time as the first stealth aircraft were in the 1980s and ’90s. One of them, the Convair B-58 Hustler, looks radical even today
With its long, slender fuselage, dramatically swept delta wing, and four big engines, the B-58 looked fast even when it was on the ground. It was one of the first aircraft to take advantage of the knowledge that the way to overcome drag in supersonic flight is to sweep the wings at such an angle that the aircraft flies within the Mach cone, a three-dimensional bow wave formed around a body moving through the air at supersonic speed. When the wings are within that cone, the airflow over them remains subsonic. So successful were the Convair aerodynamicists at managing supersonic flight that on October 15, 1959, the first production Hustler flew faster than Mach 2 for more than an hour. Refueling once, the aircraft traveled 1,680 miles in 80 minutes.
The world’s first supersonic bomber inherited its delta wing from earlier Convair projects: The XF-92A was the world’s first delta wing aircraft and the foundation for Convair’s F-102, the world’s first supersonic interceptor.
Early in the development phase, engineers on the XF-92A discovered during wind tunnel tests that the highly swept, narrow-chord wing was very unstable. A Vultee aerodynamicist, Ralph Shick, suggested a solution to Adolph Burstein, chief technologist, and Frank Davis, test pilot and head of Aero and Flight Test: “Why don’t we just fill in the area between the two wing tips?” Shick hypothesized that changing to a single, triangle-shaped wing would generate more stability and control. He was right.
Although the delta wing concept first appeared during World War II in Germany, Bill Chana, a former XF-92A flight test engineer, says the XF-92A’s design was a Convair original. “A lot of people think Burstein and Shick got the delta idea from the Germans,” says Chana. “That’s just not true. Their delta wing configuration for the Convair interceptor was their own thinking.”
By early 1953, Convair had begun work on the XB-58 and XBR-58. They relied on their findings from the XF-92A program (retired in 1953) and 10,000 design configurations they explored to advise the Air Force, under a general study, of the designs that would promise the best performance for supersonic bombers.
“The original mission profile for the B-58 was to cruise to the target area at .91 Mach, then dash at Mach 2-plus above 50,000 feet for approximately 500 miles,” remembers Harold “Hal” Confer, the second Strategic Air Command pilot to be certified as operational in the B-58. “We’d drop the pod containing the nuclear weapon and return to home base at .91 Mach cruise. We could outrun and out-distance all of our fighters of that era, which certainly brought a smile to the face of this old bomber pilot.”
“When the B-58 was designed, [the Russians] hadn’t really perfected a surface-to-air-missile system and didn’t have a high-altitude supersonic fighter yet,” says Ben Baddley, a B-58 navigator/bombardier. “The B-58 was created to take advantage of that situation.”