Page 7 - The Future of Aerospace is X - X-Planes 2021

X-1, from 6
acteristic of fast (Mach 2 plus) su- aircraft spun out of control, due to transferred to NACA during January a new low-pressure fuel system and two lives, caused injuries and lost
personic flight: inertia coupling. Only the then not yet understood phenom- 1955. NACA continued to fly the air- a slightly increased fuel capacity. several aircraft.
Yeager’s skills as an aviator prevent- enon of inertia coupling. The X-1A craft until January 1958, when cracks There were also some minor changes The changes included:
ed disaster. Later Mel Apt would lose dropped from maximum altitude to in the fuel tanks forced its ground- of the avionics suite. • A turbopump fuel feed system,
his life testing the Bell X-2 under 25,000 feet, exposing the pilot to ac- ing. The X-1B completed a total of On July 24, 1951, with Bell test which eliminated the high-pressure
similar circumstances. celerations of as much as 8g, during 27 flights. A notable achievement pilot Jean “Skip” Ziegler at the nitrogen fuel system used in ‘062 and
which Yeager broke the canopy with was the installation of a system of controls, the X-1D was launched ‘063. Concerns about metal fatigue
X-1A — Bell Model 58A his helmet before regaining control. small reaction rockets used for direc- over Rogers Dry Lake, on what was in the nitrogen fuel system resulted
Ordered by the Air Force on April On May 28, 1954, Maj. Arthur W. tional control, making the X-1B the to become the only successful flight in the grounding of the X-1-2 after
2, 1948, the X-1A (serial number Murray piloted the X-1A to a new first aircraft to fly with this sophis- of its career. The unpowered glide its 54th flight in its original configu-
48-1384) was intended to investigate record of 90,440 feet. ticated control system, later used in was completed after a nine-minute ration.
aerodynamic phenomena at speeds The aircraft was transferred to the North American X-15. The X-1B descent, but upon landing, the nose • A re-profiled super-thin wing,
greater than Mach 2 and altitudes NACA during September 1954, and is now at the National Museum of landing gear failed and the aircraft based on the X-3 Stiletto wing pro-
greater than 90,000 feet, specifically subsequently modified. The X-1A the United States Air Force, where slid ungracefully to a stop. Repairs file, enabling the X-1E to reach Mach
emphasizing dynamic stability and was lost on Aug. 8, 1955, when, it is displayed in the Museum’s Maj. took several weeks to complete and a 2.
air loads. Longer and heavier than the while being prepared for launch Gen. Albert Boyd and Maj. Gen. Fred second flight was scheduled for mid- • A ‘knife-edge’ windscreen re-
original X-1, with a stepped canopy from the airborne RB-50 mothership, Ascani Research and Development August. On Aug. 22, 1951, the X-1D placed the original greenhouse glaz-
for better vision, the X-1A was pow- an explosion ruptured the plane’s Gallery. was lost in a fuel explosion during ing. An upward-opening canopy re-
ered by the same Reaction Motors liquid oxygen tank. With the help preparations for the first powered placed the fuselage side hatch and
XLR-11 rocket engine. The aircraft of crewmembers on the RB-50, test X-1C — Bell Model 58C flight. The aircraft was destroyed allowed the inclusion of an ejection
first flew, unpowered, on Feb. 14, pilot Joseph A. Walker successfully The X-1C (serial 48-1387) was in- upon impact after it was jettisoned seat.
1953, at Edwards, with the first pow- extricated himself from the plane, tended to test armaments and muni- from its EB-50A mothership. • The addition of 200 pressure
ered flight on Feb. 21. Both flights which was then jettisoned. Explod- tions in the high transonic and super- ports for aerodynamic data, and 343
were piloted by Bell test pilot Jean ing on impact with the desert floor, sonic flight regimes. It was canceled X-1E — Bell Model 44 strain gauges to measure structural
“Skip” Ziegler. the X-1A became the first of many while still in the mockup stage, as the The X-1E was the result of a re- loads and aerodynamic heating along
After NACA started its high- early X-Planes that would be lost to development of transonic and super- construction of the X-1-2 (serial the wing and fuselage.
speed testing with the Douglas Sky- explosions. sonic-capable aircraft like the North 46-063), in order to pursue the goals The X-1E first flew on Dec. 15,
rocket, culminating in Scott Cross- American F-86 Sabre and the North originally set for the X-1D and X-1- 1955, a glide-flight controlled by Air
field achieving Mach 2.005 on Nov. X-1B — Bell Model 58B American F-100 Super Sabre elimi- 3 (serial 46-064), both lost in explo- Force test pilot Joe Walker. Walker
20, 1953, the Air Force started a The X-1B (serial 48-1385) was nated the need for a dedicated experi- sions during 1951. left the X-1E program during 1958,
series of tests with the X-1A, which equipped with aerodynamic heat- mental test vehicle. The cause of the mysterious explo- after 21 flights, attaining a maximum
the test pilot of the series, Yeager, ing instrumentation for thermal re- sions was finally traced to the use of speed of Mach 2.21. NACA research
named “Operation NACA Weep”. search (more than 300 thermal probes X-1D — (Bell Model 58D Ulmer leather gaskets impregnated pilot John B. McKay took his place
These culminated on Dec. 12, 1953, were installed on its surface). It was The X-1D (serial 48-1386) was with tricresyl phosphate (TCP), a during September 1958, completing
when Yeager achieved an altitude of similar to the X-1A except for having the first of the second generation leather treatment, which was used five flights in pursuit of Mach 3 before
74,700 feet and a new airspeed record a slightly different wing. of supersonic rocket planes. Flown in the liquid oxygen plumbing. TCP the X-1E was permanently grounded
of Mach 2.44. Unlike Crossfield in The X-1B was used for high-speed from an EB-50A (s/n #46-006), it becomes unstable and explosive in after its 26th flight, during November
the Skyrocket, Yeager achieved that research by the U.S. Air Force start- was to be used for heat transfer re- the presence of pure oxygen and 1958, due to the discovery of struc-
in level flight. Soon afterwards, the ing in October 1954, prior to being search. The X-1D was equipped with mechanical shock. This mistake cost tural cracks in the fuel tank wall.

Aerotech News and Review
July 16, 2021 www.aerotechnews.com ........ facebook.com/aerotechnewsandreview 7