Bell X-1

The rocket-powered Bell X-l was the first aircraft to fly at above the speed of sound. It was built expressly to investigate the problem of “breaking the sound barrier”, then regarded with some trepidation.
The X -1 was straight-winged and aerodynamically clean, with a fuselage modelled along the lines of a 0.50-calibre bullet. For its experimental flights, it was carried aloft in the bomb-bay of a B-29
bomber and released at high altitude. Its four-chamber rocket motor used up its alcohol and liquid oxygen fuel in a few minutes, after which the aircraft was landed as a glider. The X-1 made its first powered flight on 29 August 1947, piloted by Captain Charles “Chuck” Yeager. Although the cockpit was cramped, the aircraft proved docile and a pleasure to fly.
The big event came on 14 October 1947, on flight 50 of the test programme. Piloting an X-1 he had named Glamorous Glennis. in tribute to his wife, Yeager was released at 20,000ft, then ignited two chambers of the rocket motor for initial acceleration and climb. At 40.000 feet be levelled off and ignited the other two chambers.
Seconds later the Bell X-l smoothly accelerated through Mach 1 – the speed of sound – to Mach 1.06. Ten minutes later Yeager was safely back on the ground, and history had been made.