Dave Majumdar remembers the coolest bomber nobody ever deployed:
The idea behind the XB-70 originated in the 1950s when it was assumed ever-greater speeds and altitudes would enable American bombers to survive against Soviet air defenses unmolested on their way to delivering their doomsday payloads. At the time, the only effective defense against bombers were fighters and antiaircraft artillery. Even then, anti-aircraft guns were only marginally effective and interceptors were increasingly challenged by ever improving bomber performance.
However, with the advent of surface-to-air missiles (SAM), that began to change—the balance started to tip in favor of the defender. While the U.S. Air Force was aware of Soviet advances in SAM technology, the Pentagon didn’t start to understand the scope of the problem until Francis Gary Powers’ Lockheed U-2 spy plane was shot down while overflying the Soviet Union on May 1, 1960. But development of the XB-70 continued nonetheless.
The Valkyrie would have stressed ’60s technology to the limit, delivering the same payload as a lumbering B-52 Stratofortress, but at speeds up to 50% faster than the B-58 Hustler. Range would have been sacrificed, and as Majumdar notes, the B-70 was no faster than the B-52 at low altitude, and vulnerable to surface-to-air missiles even at high altitudes. And they would have been far more expensive to build, fly, and maintain.
The last XB-70 flew its last flight in February of 1969.
But imagine a world where Gary Powers wasn’t shot down, and where the Pentagon remained oblivious to Moscow’s advances in SAM technology. We might very well have wasted billions on “the wrong plane for the wrong time.” We lost 15 B-52s bombing North Vietnam into submission during Linebacker II, out of a deployed force of 207. Nine more suffered medium-to-heavy damage. Had we tried a similar operation using B-70s, it’s almost certain we’d have lost far more planes and many more crews to Hanoi’s tough air defenses.
And in the event of a shooting war with the Soviets, the premier portion of the bomber leg of our nuclear triad would have been far more vulnerable than the Stratofortresses the Valkyrie had been designed to replace.
Given our current need for long-range/slower-moving bombers like the BUFF, the high-flying/fast-moving B-70 would be even more out of place in 2015 than in 1965.
Still, moving 50,000 pounds of ordnance at Mach 3 would have been a helluva thing.
The B-70 has got to be the best bomber we never needed.