The XB-70 Valkyrie: A Precursor to Supersonic Passenger Travel
Historical Context:
Five years before the inaugural flight of the Concorde, the United States Air Force developed the XB-70 Valkyrie, an experimental aircraft that ushered in the golden era of supersonic flight with its first flight in September 1964. With a maximum speed exceeding 3,218 kilometers per hour (2,000 miles per hour), the Valkyrie was notably faster than the Concorde by nearly 50%, according to CNN. NASA also utilized the XB-70's pre-production prototype for high-speed flight research throughout the 1960s.
The Program's Challenges
The XB-70 program encountered its share of obstacles. Intended as a military aircraft, it became obsolete even before its deployment, with its short-lived existence marked by a fatal crash. Despite these setbacks, the aircraft's design remains a testament to the cutting-edge engineering of supersonic flight.
Design Innovations
The XB-70 Valkyrie emerged from a competition between Boeing and North American Aviation, then a prominent aerospace manufacturer, which the U.S. Air Force selected in 1957 to develop a bomber capable of delivering weapons at speeds of 1,535 kilometers per hour (954 miles per hour) and altitudes of 18,288 meters (60,000 feet). However, the downing of a U-2 spy plane over the Soviet Union in 1960 prompted a shift from manned bombers to intercontinental ballistic missiles. By 1961, President Kennedy deemed the proposed XB-70 unlikely to penetrate enemy defenses, leading to a refocusing of the program on high-speed research.
The first prototype XB-70, nicknamed Valkyrie, took flight in Palmdale, California, on May 11, 1964. Boasting a wingspan of over 30 meters (98 feet), a length of 56 meters (185 feet), and powered by six turbojet engines, it was one of the most impressive aircraft ever built. A defining feature was its variable-geometry wings, which remained horizontal at subsonic speeds but folded down to reduce drag at supersonic speeds. The XB-70 Valkyrie's key design aspects, such as its delta wings and slender fuselage, influenced both the Concorde and its Soviet counterpart, the Tupolev Tu-144. The Tupolev Tu-144 even incorporated the XB-70's drooping canard foreplanes behind the cockpit for improved maneuverability at low speeds.
Supersonic Passenger Aircraft Designs
As more information became available over time, the design of supersonic passenger aircraft, such as the Concorde, became more refined. While the Valkyrie's role as a bomber was abandoned, designers considered modifications for a transport version serving both military and civilian purposes.
The passenger experience on such aircraft would have been far from ordinary, likely resembling that of the Concorde, with ample legroom and a quiet cabin. Due to the high operating costs and limited seating capacity, fares would have been accessible only to the wealthy and upper-middle class. The aircraft's rapid transit times, however, would have significantly reduced travel duration, connecting London and New York in 2.5 hours compared to the Concorde's 3.5-hour flight.
Program Termination and Legacy
A fatal accident in 1966 cut short the XB-70 program during a photo shoot organized by General Electric. The second Valkyrie, more advanced than its predecessor, collided with a smaller F-104N aircraft mid-air, resulting in the deaths of two pilots and severe injuries to another. The destroyed Valkyrie had only flown 46 times, while the remaining aircraft concluded its career with 83 flights and over 160 hours in the air. Its final flight in 1969 carried it from NASA's Armstrong Flight Research Center in California to Wright-Patterson Air Force Base in Ohio, where it joined the collection at the Air Force Museum.
Summary:
The XB-70 Valkyrie, conceived as a military aircraft, played an instrumental role in shaping the design of supersonic passenger aircraft like the Concorde. Despite its ultimate cancellation due to technical challenges, its innovative features and influence on future aircraft cannot be overstated. The Valkyrie's legacy as a trailblazing supersonic jet remains etched in aviation history.