 In order to achieve this feat, the aircraft would have to be capable of maintaining Mach 2.5 at an altitude of 60,000 ft (18,300 m), along with the ability to attain at least Mach 3 and operate at a maximum range of 5,754 mi (9,260 km).By operating at such a high altitude and speed, along with assorted advanced electronic systems on board, it was believed that the specified aircraft would be capable of evading the threats posed by Soviet interceptor aircraft and newly developed surface-to-air missiles alike.Upon its issuing, Specification OR.330 effectively called for the most ambitious high-performance aircraft in the world.