<P> There are a number of unmanned vehicles that flew at supersonic speeds during this period, but they generally do not meet the definition . In 1933, Soviet designers working on ramjet concepts fired phosphorus - powered engines out of artillery guns to get them to operational speeds . It is possible that this produced supersonic performance as high as Mach 2, but this was not due solely to the engine itself . In contrast, the German V - 2 ballistic missile routinely broke the sound barrier in flight, for the first time on 3 October 1942 . By September 1944, V - 2s routinely achieved Mach 4 (1,200 m / s, or 3044 mph) during terminal descent . </P> <P> In 1942, the United Kingdom's Ministry of Aviation began a top - secret project with Miles Aircraft to develop the world's first aircraft capable of breaking the sound barrier . The project resulted in the development of the prototype Miles M. 52 turbojet powered aircraft, which was designed to reach 1,000 mph (417 m / s; 1,600 km / h) (over twice the existing speed record) in level flight, and to climb to an altitude of 36,000 ft (11 km) in 1 minute 30 sec . </P> <P> A huge number of advanced features were incorporated into the resulting M. 52 design, many of which hint at a detailed knowledge of supersonic aerodynamics . In particular, the design featured a conical nose and sharp wing leading edges, as it was known that round - nosed projectiles could not be stabilised at supersonic speeds . The design used very thin wings of biconvex section proposed by Jakob Ackeret for low drag . The wing tips were "clipped" to keep them clear of the conical shock wave generated by the nose of the aircraft . The fuselage had the minimum cross-section allowable around the centrifugal engine with fuel tanks in a saddle over the top . </P> <P> Another critical addition was the use of a power - operated stabilator, also known as the all - moving tail or flying tail, a key to supersonic flight control which contrasted with traditional hinged tailplanes (horizontal stabilizers) connected mechanically to the pilots control column . Conventional control surfaces became ineffective at the high subsonic speeds then being achieved by fighters in dives, due to the aerodynamic forces caused by the formation of shockwaves at the hinge and the rearward movement of the centre of pressure, which together could override the control forces that could be applied mechanically by the pilot, hindering recovery from the dive . A major impediment to early transonic flight was control reversal, the phenomenon which caused flight inputs (stick, rudder) to switch direction at high speed; it was the cause of many accidents and near - accidents . An all - flying tail is considered to be a minimum condition of enabling aircraft to break the transonic barrier safely, without losing pilot control . The Miles M. 52 was the first instance of this solution, and has since been universally applied . </P>

How many g forces is the speed of sound