Country of origin:

United States of America

Description:

Single-seat high-speed high-altitude research aircraft

Power Plant:

One 6,000 lb thrust Reaction Motors RMI LR-8-RM-3 liquid propellant rocket motor

Specifications:

History:

In the 1950s aircraft manufacturers were looking at an aircraft that was capable of passing through the ‘sound barrier’, the Mach scale having been named after Ernest Mach, an Austrian, Mach 1 being considered to be the speed of sound. It was calculated the speed of sound at 15 degrees Celcius at sea level was 1,225.41 km/h (761.45 mph), whereas at 10,973 m (36,000 ft) it was 1,063.1 km/h (660.6 mph). During World War II aircraft were approaching the speed of sound in a dive.

The US Navy and the US Army Air Corps sought answers to high-speed aerodynamics and, with the NACA Langley Laboratory in Virginia, decided to build a rocket-powered aircraft which would be launched from a Boeing B-29 mother-ship in an attempt to achieve supersonic flight.

A contract was issued to the Bell Aircraft Corporation to build the XS-1 [Experimental Sonic] aircraft No 1 (serial 46-062) on 16 March 1946. When completed the aircraft was taken to the Muroc US Army Air Field in 1947, this area later becoming known as Edwards Air Force base in Kern County in southern California.

The US Army took control of the project, Colonel Albert Boyd being the commanding officer, Captain Charles “Chuck” Yeager the pilot, and Robert ‘Bob’ Hoover flying the Lockheed P-80 Shooting Star chase aircraft. The first XS-1 was launched from a Boeing B-29 Superfortress and three non-powered flights were made, the first on 25 January 1946. Test pilot was Jack Woolams, chief test pilot for Bell Aircraft, this flight being made over Pinecastle Army Airfield in Florida. In all he made nine non-powered flights. Further flights were made by Chalmers Goodlin who made 26 flights in Bell X-1 (as it had become known) serial 46-062.

However, the US Army was wanting to progress the flight envelope and the flight-test program was taken over by the US Army Air Force Flight Test Division in June 1946. At this time the second Bell X-1 46-063 was completed and its testing was to be carried out by the National Advisory Committee for Aeronautics (NACA).

The first Bell XS-1 aircraft was named ‘Glamorous Glennis’ after the wife of Colonel Yeager. On the 9th flight on 14 October 1947 the aircraft flown by Colonel Yeager was dropped from the Boeing B-29, the four Reaction Motors rocket engines were lit and the aircraft climbed to 19,507 m (64,000 ft), levelled off for 18 seconds and flew at Mach 1.06 (1,298.55 km/h / 806.88 mph). This was the first occasion on which supersonic flight was achieved in level flight, a couple of previous aircraft having flown through Mach 1 in a dive, and was the 50th flight made by the XS-1 [as it was then known]. On 5 January 1949 aircraft 46-062 flown by Colonel Yeager carried out a conventional launch from a runway, reaching 7,010 m (23,000 ft) in 90 seconds.

The engine was developed and built by Reaction Motors Inc, this unit burning ethyl alcohol diluted with water with a liquid oxygen oxidiser. The thrust could be altered by using just one chamber at a time, each providing 1,500 lb thrust. The fuel and oxygen tanks in the first two aircraft built were pressurised with nitrogen.

Development aircraft were built to continue the aerodynamics involved with supersonic flight, the X-1A (serial 48-1384) attaining Mach 2 (2,451 km/h – 1,523 mph) on 2 April 1948, being fitted with a Reaction Motors XLR-11 engine. On 12 December 1953 Colonel Yeager achieved an altitude of 22,769 m (74,700 ft) and a speed of Mach 2.44 (2,608 km/h – 1,620 mph). This aircraft was followed by the X-1B (serial 48-1385) which was fitted out for thermal research and was similar to the X-1A but had a new design wing. This machine carried out a total of 27 flights before being eventually retired to the National Museum of the United States Air Force at Dayton, Ohio.

The Bell X-1C (serial 48-1387) was expected to be used to test armament and munitions at transonic and supersonic speeds but in the event only a mock-up had been built when the program was cancelled. The X-1D (serial 48-1386) was completed and launched from a Boeing EB-50A (serial 46-006) on 24 July 1951 with Bell test pilot Jean Ziegler at the controls over the Rogers Dry Lake but this aircraft was destroyed following a fuel explosion.

The Bell X-1E was the second X-1 (serial 46-063) rebuilt and flown on 15 December 1955, this being a non-powered flight with test pilot Joe Walker at the controls. He made 21 flights in the aircraft reaching Mach 2.21 (2,704 km/h – 1,680 mph). NACA research pilot John McKay took over the testing in September 1958 but the aircraft in November that year was grounded due to structural cracks in the fuel tank.

Three of the original aircraft survive: X-1 (serial 46-062) on display at the National Air & Space Museum in Washington; the X-1B (serial 48-1385) at the USAF Museum in Dayton, Ohio; and the X-1E (serial 46-063) at the NASA Armstrong Flight Research Centre at Edwards Air Force Base in California.

In March 2007 at the Australian International Air Show at Avalon, VIC the breaking of the sound barrier, and the building, development and flight of the Bell X-1 series, was celebrated on its 60th Anniversary. A full-scale mock-up of the Bell X-1 was constructed and displayed, the show being themed as ‘Breaking the Barriers’.  Colonel ‘Chuck’ Yeager was the Guest of Honour at the show, placing his signature on the replica aircraft, and was the guest speaker at the ‘Breaking the Barriers’ Award presentations at the show. The aircraft was later placed in storage and in later years has been stored with the collection of aircraft operated by Judy Pay at Tyabb, VIC.