The North American XB-70 Valkyrie was a long range strategic nuclear bomber designed for the United States Air Force's Strategic Air Command. With research and development studies beginning in 1955, the XB-70 was slated to replace the B-52 Stratofortress. It was designed to be a large, high altitude bomber with six engines to fly at Mach 3 to avoid defending interceptors, the only effective anti-bomber weapon at the time. Although a technology breakthrough in 1957 made Mach 3 possible, the XB-70 never entered production.
As in the B-58 Hustler program, the Air Force wanted new technology advances in the new aircraft and gave the prime contractor total weapon system responsibility. Boeing and North American competed for the contract, and in 1958 the North American design was chosen. The Air Force required for a high altitude, long range bomber capable of carrying nuclear and conventional weapons. The XB-70 was fabricated using titanium and brazed stainless steel honeycomb materials to withstand the heating during the sustained high Mach number portions of the flights. It was capable of carrying both conventional and nuclear weapons internally, but due to its design and Mach 3 mission profile, it could not carry external ordnance.
The first XB-70 had its maiden flight on September 21, 1964. It was found to suffer from weaknesses in the honeycomb construction, mainly due to inexperience with fabrication and quality control of this new material. It was also troubled by hydraulic leaks, fuel leaks and problems with the complicated landing gear. On the third test flight, the XB-70 reached supersonic speeds. In the following flight, it flew past Mach 1 for 40 minutes. It was able to go at higher speeds in subsequent flights, obtaining Mach 2.14 and Mach 3.02.
The second XB-70 was selected for the National Sonic Boom Program to measure the response to sonic booms. It reached Mach 3.05 at 72,000 feet on the first sonic boom test. On June 8, 1966, after a photo shoot with four other aircraft, Valkyrie number two was involved in a mid-air collision. The first aircraft continued research, making 33 more flights before its retirement.
- 1/150 Scale Model
- 8.5 Inch Wingspan
- 15.25 Inch Length
- Material Mahogany Wood