The title for the fastest aircraft ever made depends on whether the aircraft is manned or unmanned. The unmanned NASA X-43A holds the absolute record, having reached a staggering Mach 9.6 (approx. 7,310 mph) during a flight in 2004 using experimental scramjet technology. For manned aircraft, the world record belongs to the North American X-15, a rocket-powered plane that reached Mach 6.72 (4,520 mph) in October 1967, piloted by William J. Knight. In the realm of traditional jet engines (air-breathing aircraft), the legendary Lockheed SR-71 Blackbird remains the fastest, with a recorded speed of Mach 3.3 (2,193 mph) set in 1976. While the SR-71 is the fastest "standard" jet most people recognize, the X-15 and X-43A represent the extreme frontiers of hypersonic flight, designed specifically to test the limits of atmospheric resistance and propulsion at the very edge of space, far surpassing any commercial or standard military jet speed.