Jetrader - Summer 2015 - 42

In any event, by then the X-1s had
contributed as much as they could to the
knowledge of high-speed flight. The first
one had already been retired and the second one was being groomed for a major
upgrade. More about that one later.

The Second Generation of X-1s
In 1947, just a month after Yeager's first
supersonic flight, the Air Force had begun
studies with Bell for a follow-on to the X-1
program, and by April 1948 Bell was contracted to deliver four second-generation
models with the designations X-1A, X-1B,
X-1C and X-1D. Speeds of at least Mach
2.0 and altitudes above 90,000 feet were
targeted.
These second-generation X-1s were minimally changed derivatives of the first three,
retaining the same straight unswept wings,
but with the fuselage stretched about five
feet to make room for more fuel and liquid
oxygen. The rocket motor was an improved
model, and the flush "greenhouse" cockpit
window was replaced with a more fighterlike canopy to give the pilot a better view
looking forward.
The first of the second-generation X-1s
to be delivered by Bell was the X-1D, which
made its initial unpowered glide flight in
July 1951. This first flight was also its last.
On the next attempt, an explosion and fire
erupted in the X-1D aft fuselage as it was
about to be dropped from the B-50 mother
ship. The pilot scrambled back into the
B-50 bomb bay and the smoking X-1D was
jettisoned.

The unlucky third X-1, tail number 6064 being loaded onto the B-50 mother ship. The B-50 was
raised on hydraulic jack-pads, then the X-1 was rolled into position and hoisted up into the bomb
bay. This X 1 made only one glide flight. It exploded on the ground while attached to the B-50
before what would have been its second flight. Photo courtesy of NASA.

At this point in mid-1951, there were no
flyable X-1s left. X-1 number 1, Glamorous
Glennis, had gone to the Smithsonian, X-1
number 2 was in mothballs, X-1 number
3 had exploded on the ground, and the
X-1D was a sad pile of wreckage out on the
desert. No X-1s flew in 1952.

Back in Business, the X-1A and
X-1B Twins
Next up was the X‑1A, making its first
glide flight in February 1953, followed later

42 743859_KLM.indd publication of the International Society of Transport Aircraft Trading
The official 1

by its twin, the X-1B. Yeager got the X-1A
up to Mach 1.9 on its third powered flight.
As described in his autobiography, Yeager
had misgivings about the X-1A. If something went wrong he wouldn't be able to get
out of it; it had no ejection seat. Neither
did the original X-1, but at least with the
X-1 he could jettison the cockpit door and
bail out. Not so with the X-1A. Once he got
in, the canopy was bolted into place, to
be later unbolted from the outside by the
ground crew back at Edwards. If the ship

30/04/15 10:30 pm

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Jetrader - Summer 2015

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