The XB-70A Valkyrie
The 1950s saw the development of the futuristic XB-70A Valkyrie, a high-altitude, nuclear strike bomber capable of flying at Mach 3, or three times the speed of sound—any potential enemy would have been unable to defend against such a bomber.
But by the early 1960s, modern Surface-to-Air Missiles (SAMs) posed a threat to high-altitude, high-speed bombers’ capacity to survive. Nuclear-armed Intercontinental Ballistic Missiles, or ICBMs, were becoming less expensive and more common. Consequently, the expensive B-70 bomber program was canceled in 1961 before any Valkyries were completed or flown.
Nevertheless, the USAF purchased two XB-70As to evaluate the aircraft’s propulsion, aerodynamics, and other features. On display here, the first XB-70A took to the skies in September 1964 and reached Mach 3 flying in October 1965. After an accidental mid-air collision in June 1966, the second Valkyrie was destroyed. It had made its first flight in July 1965. The third Valkyrie was not completed.
The first XB-70A aircraft flew and produced useful test data for the research program until 1969 when it was given to the US Air Force’s National Museum.
B-70 with `General Purpose Missile’
According to Scott Lowther’s book US Supersonic Bomber Projects, one of the more absurd-looking proposals was a North American concept for using the B-70 as a carrier for a `General Purpose Missile’. Sadly, little information is available about the missile; performance, weight data, and warhead are lacking. All that is available is a single illustration showing how a B-70 could be used to carry 18 of the missiles at once.
According to Scott Lowther’s book US Supersonic Bomber Projects, one of the more absurd-looking proposals was a North American concept for using the B-70 as a carrier for a `General Purpose Missile’. Unfortunately, there is not much information regarding the missile, including the warhead, weight, and performance. There is just a single illustration that demonstrates how eighteen of the missiles could be carried at once by a B-70.
The General Purpose Missile was depicted as a delta-winged configuration with a single ramjet engine in a separate nacelle with downward-drooping wingtips. This was clearly a standoff weapon, presumably with a small nuclear warhead. By calling it a ‘general purpose` missile, it may be that it was intended to not only strike ground targets but possibly serve an air-to-air role as well.
The diagram in this article shows where the missiles were supposed to be gathered across the great expanse of the B-70, suspended beneath the wings with pylons, attached to the tips of both the canards and the vertical stabilizers, perched atop and underneath the fuselage. The source sketch does not depict all of the necessary pylons, explaining why some of the missiles in this reconstruction are not attached to the aircraft.
Able to carry 19 GPMs
Another diagram shows an alternate design for the General Purpose Missile. This missile was similar in size with a similar-looking ramjet engine… but otherwise, the configuration was quite different, looking more like a catamaran boat with a jet engine than a normal sort of missile. This version of the GPM weighed 698lb, would fly at Mach 3 to Mach 4 at 70,000 to 90,000ft, and had a range of 975 nautical miles.
The B-70 would be able to carry 19 of this version of the GPM.
US Supersonic Bomber Projects is published by Mortons Books and is available to order here.
Photo by NASA