What was the first manned aircraft confirmed to fly faster than the speed of sound?

The first manned aircraft confirmed to fly faster than the speed of sound was the X-1. This experimental rocket-powered aircraft achieved this milestone on October 14, 1947, when test pilot Chuck Yeager flew it at a speed of Mach 1.06, which is approximately 700 miles per hour at sea level. The X-1 was specifically designed for supersonic flight, and its sleek design and advanced technology at that time made it possible to break the sound barrier.

The significance of the X-1's achievement was profound, as it not only demonstrated that controlled and sustained supersonic flight was possible but also laid the groundwork for subsequent aircraft development and exploration of the upper limits of flight performance. It served as a pioneer in aerodynamics and flight technology, contributing to our understanding of supersonic and hypersonic flight.

In contrast, while the other aircraft mentioned are notable in their own right—such as the F-86 Sabre, F-104 Starfighter, and SR-71 Blackbird—they either performed at transonic speeds or were designed for different operational roles that did not focus primarily on achieving the initial sound barrier breakthrough.