BELL X-1 41
Bell X-1
Max speed: Mach 1.45, 957mph
(1,541km/h)
Engine: 1 x Reaction Motors
XLR-11-RM3 liquid-
propellant rocket
Power: 6,000lb thrust
Length: 30ft 11in (9.4m)
Wingspan: 28ft (8.5m)
Height: 10ft (3.3m)
Max T/O weight: 12,250lb (5,557kg)
Service ceiling: 71,902ft (21,916m)A
booming thunder roared across the
clear skies of the Mojave Desert on
14 October 1947, as Capt Chuck
Yeager nudged an experimental rocket-
powered aircraft faster than the speed of
sound. Though only a handful of people
realised it at the time, history had just
been made. The ight demonstrated that
aircraft could be designed to y faster than
sound, and the concept of a ‘sound barrier’
crumbled into myth.
The XS-1 was developed as part of a co-
operative programme initiated in 1944 by the
National Advisory Committee for Aeronautics
(NACA) and the US Army Air Forces to develop
special manned transonic and supersonic
research aircraft. Bell Aircraft Corporation was
awarded a contract to develop three transonic
and supersonic research aircraft under project
designation MX-653. The Army assigned the
designation XS-1 for Experimental Sonic.
The XS-1s were constructed from high-
strength aluminium, with propellant tanks
manufactured from steel. The rst two XS-1s
did not utilise turbopumps for fuel feed to
the rocket engine, relying instead on direct
nitrogen pressurisation of the fuel-feed
system. The smooth contours of the XS-1,
patterned on the lines of a machine gun
bullet, masked an extremely crowded fuselage
containing two propellant tanks, 12 nitrogen
spheres for fuel and cabin pressurisation, the
pilot’s pressurised cockpit, three pressure
regulators, a retractable landing gear, theBell X-1
wing carry-through structure, a Reaction Motors
6,000lb-thrust rocket engine, and more than
500lb of special ight-test instrumentation.
Bell Aircraft chief test pilot Jack Woolams
became the rst person to y the XS-1 making
ten glide- ights before March 1946, when the
aircraft was returned to Bell for modi cations
to prepare for the powered ight tests. These
were performed at Muroc Army Air Field near
Palmdale, with Chalmers ‘Slick’ Goodlin as the
primary Bell Aircraft test pilot for the X-1-1 (serial
46-062). He made 26 successful ights in both
X-1s from September 1946 through June 1947.
The USAAF was unhappy with the cautious
pace of ight envelope expansion and the test
programme was acquired from Bell. 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.
Capt Charles ‘Chuck’ Yeager’ entered the
history books on 14 October 1947 when the
rst manned supersonic ight took place, less
than a month after the US Air Force had been
created as a separate service. Two days before
his historic ight, Yeager was thrown from a
horse while riding with his wife and broke two
ribs. Knowing that he would never be allowed
to y, he travelled to a doctor o base and had
them taped up. Unable to close and latch the
side door by hand, he used a broom handle at
the suggestion of a fellow pilot. Yeager and the
X-1, were dropped from the B-29, and quickly
accelerated away. As the X-1 reached Mach
1.06 (700mph), controllers on the ground heardThe need for speed
One of the greatest moments in aviation
history occurred on 14 October 1947
when the Bell X-1 became the rst aircraft
to y faster than the speed of sound in
level ight. Piloted by US Air Force Capt
Charles E. ‘Chuck’ Yeager, the X-1 reached
a speed of Mach 1.06 (700mph) at an
altitude of 43,000ft (13,000m). Yeager
named the aircraft Glamorous Glennis in
tribute to his wife.
Below: The rst man to y faster than the
speed of sound. Capt Charles ‘Chuck’ Yeager
seated in the cockpit of the Bell X-1.Left: The Bell X-1 streaks over over Rogers Dry
Lake during a test ight.Right: The B-29 mothership with the Bell X-1
slung underneath.the rst sonic boom. Following burn-out of the
engine, Yeager glided to a landing on the dry
lake bed. On 26 March 1948, again with Yeager
at the controls, the X-1 attained a speed of
Mach 1.45 (957mph) at an altitude of 71,900ft
(21,900m), the highest velocity and altitude
reached by a manned aircraft up to that time.AA33_p43.indd 43 10/08/2017 08:32