Bell X 1

Le X-1 vu par Wikipedia.en

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The [Vous devez être inscrit et connecté pour voir ce lien] X-1, originally designated XS-1, was a joint [Vous devez être inscrit et connecté pour voir ce lien]-[Vous devez être inscrit et connecté pour voir ce lien]/[Vous devez être inscrit et connecté pour voir ce lien] supersonic research project and the first [Vous devez être inscrit et connecté pour voir ce lien] to exceed the [Vous devez être inscrit et connecté pour voir ce lien] in controlled, level flight.

This resulted in the first of the so-called [Vous devez être inscrit et connecté pour voir ce lien], an [Vous devez être inscrit et connecté pour voir ce lien] series of experimental aircraft designated for testing of new technologies and usually kept highly secret.

Design and development

On 16 March 1945, the United States Army Air Forces' Flight Test Division and the [Vous devez être inscrit et connecté pour voir ce lien] (NACA) (now [Vous devez être inscrit et connecté pour voir ce lien]) contracted [Vous devez être inscrit et connecté pour voir ce lien] to build three XS-1
(for "Experimental, Supersonic", later X-1) aircraft to obtain flight data on conditions in the transonic speed range.

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The XS-1 was the first high-speed aircraft built purely for aviation research purposes and was never intended for production.

The X-1 was in principle a "bullet with wings" that closely resembled the shape of the [Vous devez être inscrit et connecté pour voir ce lien] (12.7 mm) machine gun bullet that was known to be stable in supersonic flight.

The pattern shape was followed to the point of seating the pilot behind a sloped, framed window inside a confined cockpit in the nose.

After the aircraft ran into compressibility problems in 1947, it was modified to feature a variable-incidence [Vous devez être inscrit et connecté pour voir ce lien].

An all-moving tail was developed by the British for the [Vous devez être inscrit et connecté pour voir ce lien], and first saw actual transonic flight on the Bell X-1 that allowed it to pass through the sound barrier safely.

Maquette d'étude Miles M 52

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The rocket propulsion system was a four-chamber engine built by [Vous devez être inscrit et connecté pour voir ce lien], one of the first companies to build liquid-propellant rocket engines in America.

It burned ethyl alcohol diluted with water and liquid oxygen.

The thrust could be changed in 1500 lbf increments by firing one or more of the chambers.

The fuel and oxygen tanks for the first two X-1 engines were pressurized with nitrogen and the rest with steam-driven turbopumps.

The all-important fuel turbopumps, necessary to raise the chamber pressure and thrust, while lightening the engine, were built by [Vous devez être inscrit et connecté pour voir ce lien] who was under Navy contract to provide jet-assisted takeoff rockets.

XLR-11 rocket engine on display at the National Air and Space Museum.

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Operational history

Bell Aircraft Chief [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien] became the first to fly the XS-1, in a glide flight over [Vous devez être inscrit et connecté pour voir ce lien], in Florida, on 25 January 1946.

Woolams would complete nine additional glide flights over Pinecastle before March 1946, when the #1 aircraft was returned to Bell for modifications in anticipation of the powered flight tests, planned for Muroc Army Air Field (now [Vous devez être inscrit et connecté pour voir ce lien]) in California.

Following Woolams' death on 30 August 1946, [Vous devez être inscrit et connecté pour voir ce lien] was the primary Bell Aircraft test pilot of X-1-1 (serial 46-062).

He made 26 successful flights in both of the X-1 aircraft from September 1946 until June 1947.

The Army Air Force was unhappy with the cautious pace of flight envelope expansion and Bell Aircraft's flight test contract for aircraft #46-062 was terminated and was taken over by the Army Air Force Flight Test Division on 24 June after months of negotiation.

Goodlin had demanded a US$150,000 bonus for breaking the sound barrier.
Flight tests of the X-1-2 (serial 46-063) would be conducted by NACA to provide design data for later production high-performance aircraft.

On 14 October 1947, just under a month after the [Vous devez être inscrit et connecté pour voir ce lien] had been created as a separate service, the tests culminated in the first manned supersonic flight, piloted by Air Force [Vous devez être inscrit et connecté pour voir ce lien] in aircraft #46-062, which he had christened Glamorous Glennis after his wife.

The [Vous devez être inscrit et connecté pour voir ce lien]-powered aircraft was launched from the bomb bay of a specially modified [Vous devez être inscrit et connecté pour voir ce lien] and glided to a landing on a runway.

XS-1 flight number 50 is the first one where the X-1 recorded supersonic flight, at Mach 1.06 (361 m/s, 1,299 km/h, 807.2 mph) peak speed; however, Yeager and many other personnel believe Flight #49 (also with Yeager piloting), which reached a top recorded speed of Mach 0.997 (339 m/s, 1,221 km/h), may have, in fact, exceeded Mach 1.

(The measurements were not accurate to three significant figures and no [Vous devez être inscrit et connecté pour voir ce lien] was recorded for that flight.)

As a result of the X-1's initial supersonic flight, the [Vous devez être inscrit et connecté pour voir ce lien] voted its 1948 [Vous devez être inscrit et connecté pour voir ce lien] to be shared by the three main participants in the program.

Honored at the [Vous devez être inscrit et connecté pour voir ce lien] by President [Vous devez être inscrit et connecté pour voir ce lien] were [Vous devez être inscrit et connecté pour voir ce lien] for Bell Aircraft, Captain Yeager for piloting the flights, and [Vous devez être inscrit et connecté pour voir ce lien] for the NACA contributions.

Histoire du Collier Trophy :

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On 5 January 1949, Yeager used Aircraft #46-062 to carry out the only conventional (runway) take off performed during the X-1 program, reaching 23,000 ft in 90 seconds.

Legacy

The research techniques used in the X-1 program became the pattern for all subsequent X-craft projects.

The NACA X-1 procedures and personnel also helped lay the foundation of America's space program in the 1960s.

The X-1 project defined and solidified the post-war cooperative union between U.S. military needs, industrial capabilities,
and research facilities.

The flight data collected by the NACA in the X-1 tests then provided a basis for American aviation supremacy in the latter half of the 20th century.