The XB-70 Valkyrie, a U.S. Air Force aircraft with a speed of 3,218 km/h, inspired the design of later civilian supersonic aircraft such as the Concorde and the Tupolev Tu-144.
Five years prior to the first flight of the Concorde, another supersonic aircraft took to the skies. That was the XB-70 Valkyrie, a test aircraft developed by the U.S. Air Force. Its first flight, which occurred 60 years ago in September 1964, opened a golden era for supersonic flight. The aircraft later achieved speeds exceeding 3,218 km/h, nearly 50% faster than the Concorde, according to CNN.
NASA used the pre-production prototype of the XB-70 for high-speed flight research in the 1960s. (Photo: NASA).
The XB-70 program faced its own challenges. As a military aircraft, it became outdated even before its deployment. Its brief lifespan was marked by a catastrophic accident. However, the design of the aircraft remains an icon of supersonic flight.
The XB-70 Valkyrie emerged from the competition between Boeing and North American Aviation, a major aerospace manufacturer that had been selected by the U.S. Air Force in 1957 to develop a bomber capable of carrying weapons at speeds of 1,535 km/h and altitudes of 18,288 m. However, the shooting down of a U-2 reconnaissance aircraft by the Soviet Union in 1960 led to a shift from manned bombers to ballistic missiles. In 1961, President Kennedy believed that the next XB-70 model had little chance of successfully penetrating enemy defenses. Consequently, the program’s focus shifted to high-speed flight research.
The first XB-70 model, nicknamed Valkyrie, was deployed in Palmdale, California, on May 11, 1964. With a wingspan of over 30 m and a length of 56 m, equipped with 6 turbojet engines, it was one of the most impressive aircraft ever built. A distinctive feature of the aircraft was its wing, which remained horizontal at subsonic speeds but folded back at supersonic speeds to reduce drag. Key design features such as the delta wing and the slender fuselage of the XB-70 Valkyrie were emulated by both the Concorde and its Soviet counterpart, the Tupolev Tu-144. The Tupolev Tu-144 even had a canard wing behind the cockpit similar to the XB-70, allowing pilots better control at lower speeds.
Over time, as more information became available, the design of passenger supersonic aircraft became more refined, as seen in the Concorde. After the bomber role of the Valkyrie was eliminated, designers conceived the idea of a military and civilian transport variant.
It is hard to imagine what passengers would experience on such an aircraft, but it could be quite similar to the Concorde, offering a smooth ride and spacious seating between rows. Due to the aircraft’s operational costs and limited seating, ticket prices would only be feasible for the wealthy and affluent middle class. Importantly, the aircraft was incredibly fast, making the journey between London and New York in 2.5 hours compared to 3.5 hours with the Concorde.
The XB-70 program was curtailed by a fatal accident in 1966 during a photo shoot organized by General Electric. The more advanced second Valkyrie collided with a smaller F-104N aircraft in mid-air, resulting in the deaths of two pilots and severe injuries to another. The destroyed Valkyrie had only flown 46 missions, while the other concluded its career after 83 flights and over 160 hours in the air. The final flight took place on February 4, 1969, to transport the aircraft from NASA’s Armstrong Flight Research Center in California to Wright-Patterson Air Force Base in Ohio, where it joined the collection at the National Museum of the United States Air Force.
