_Excitement and Frustration_
“You might as well try a rocket flight,” Joe Vensel said.
We were sitting in his office, which faced the NACA hangar workshop.
His tone lacked enthusiasm. His whole attention seemed focused on the
pencil he was twirling between his fingers.
It was the day after Christmas, twenty days since my first X-4
flight. The Chinese Communists had entered the Korean War,
splitting and decimating our armies on the peninsula. The President
had declared a state of national emergency. In the Pentagon the
economizing Secretary of Defense, Louis Johnson, had been replaced by
General George Marshall. The aviation industry, now overwhelmed with
money, was gearing for a future freighted with uncertainty, perhaps
a global war with the Soviet Union. Its engineers desperately needed
data. Wind-tunnel results from scale models of the newly designed,
supersonic, Century Series jet fighters--the F-100, the F-101, F-102,
and F-104--had foreshadowed critical instability at high speed. Every
man at NACA was anxious to press ahead.
“Okay,” I said. “I’ll tell them to get 945 ready.”
The number 945 was our mundane designation for the Douglas D-558-II
Skyrocket, a research airplane with an impressive background and a
sensational future.
It requires much time and planning to prepare a rocket plane for
a test flight. This was especially true in those pioneering days.
Rocket engines are complicated and temperamental, something like the
engines of expensive high-speed racing cars. They burn a powerful,
dangerous fuel combination of liquid oxygen (Lox) and water-alcohol,
and sometimes even more exotic fuels, which eat into the pipes and
fittings, corroding or unsealing joints. The fuel is pumped into the
engine through a complex maze of plumbing, which forever leaks and
loses pressure. The liquid oxygen is very cold, approaching minus
300 degrees Fahrenheit. This intense cold forms a coating of ice on
the outside of the tanks and the plane, and permeates everything,
sometimes freezing systems not designed for extreme temperatures. The
preparation of a rocket engine for flight was always an adventure for
our mechanics.
I made my way into the hangar to pass on the word to Eddy Layne, our
crew chief on 945.
“How about it, Eddy?” I said. “Can we fly tomorrow?” The skin of 945
lay about the hangar floor. The bare skeleton was under siege by half
a dozen mechanics, who appeared to be devouring the plane like so
many piranha fishes. It hardly seemed possible that it could all be
reassembled in one day.
“Sure thing, Scotty,” Eddy said. “Got a leaky regulator in the fuel
tank, but we’ll get it squared away in a while. Go ahead and plan on
it. Is this a speed run?”
“No, just a check-flight,” I said.
“I think Bridgeman and the Douglas people will be flying 943 in the
morning. You might want to touch base with them.”
“Right,” I said. It was obvious that I had not yet scored among the
mechanics. What Eddy meant was that I had better check with Bridgeman
and find out how to fly the 945. I had already done that.
I remained in the hangar for some time, looking over the ship and
recalling the plane’s history.
In late 1944, when the Air Force and NACA launched the X-1, the
Navy, as part of the overall research airplane program, began a
separate project of its own, referred to as the D-558. (In the
Navy’s hopelessly confusing aircraft terminology, the “D” stands for
Douglas, the manufacturer.) The D-558 “Skystreak” was similar to the
X-1 in shape; the main difference was that the plane was powered by
a jet instead of a rocket engine. The X-1, which was intended to be
launched in the air from a mother plane, would fly fast in brief
bursts. The D-558, which was designed to take off conventionally from
a runway, was slower, but it could stay aloft longer. Between the two
designs, it was thought, the aerodynamics in the trouble area at, or
just below, the speed of sound could be thoroughly blanketed.
Three of the original jet-powered D-558 Skystreaks were built. In
August, 1947, a couple of months before Yeager flew the X-1 through
the sound barrier, Navy Commander Turner Caldwell, flying the first
D-558, set a speed record of 640.7 miles an hour. Five days later
Marine Major Marion Carl pushed the same plane to 650.6 miles an
hour, a speed considered sensational at that time. In May, 1948, the
“time bomb” engine in one D-558 blew up on take-off, killing NACA
test pilot Howard Lilly. The second airplane became a Hangar Queen
and was cannibalized for parts. The third Skystreak was still at NACA
gathering data. I had flown it before my first hop in the X-4.
From the outset the D-558 program grew into a second generation of
airplanes. To distinguish these from the earlier models, we called
the later ones “Phase Two” airplanes, which was short for D-558-II.
The plane was popularly called the “Skyrocket.” Three Phase Two
airplanes were built, all with the new swept wing. In 1946 there
was then much controversy, but little swept-wing flight data except
those which we had obtained from the Nazis. In each of the Phase Two
airplanes, the power-plant or launch scheme was deliberately varied
to cover a wide range of research possibilities. The first Phase Two
model was, like the 558-I, powered by a single jet engine. Designed
to take off conventionally, it was fitted with two small jettisonable
rocket bottles (JATO) to help boost it into the sky. The second
model, also intended for conventional ground take-off, was powered
by a jet engine _and_ a rocket engine, similar to the rocket engine
in the X-1. The third model (945), built to be dropped from a mother
plane like the X-1, was also equipped with a jet and rocket-engine
combination. Its maximum speed was about Mach 1.2, somewhat slower
than the X-1’s top of Mach 1.4.
Douglas test pilots John Martin and Gene May first flew these
tricky Phase Two’s, taking off from the ground, burning the rocket
barrel, the jet engine, or both at once. The adventures they logged
would make a book in themselves. Ex-Navy pilot Bill Bridgeman of
Douglas was later recruited to make the Phase Two air-launched
demonstrations. By the time I arrived at NACA, the Phase Two
Skyrocket was a familiar sight on the Edwards runway, and Bill
Bridgeman was on his way to the Hall of Fame.
Bridgeman flew the jet-rocket ground take-off version of the plane
fairly regularly at Edwards. The jet-only JATO-boosted version never
really panned out. The Navy ordered it shipped back to the factory
for changeover to an all-rocket version, designed for an air-launch
(causing even more model confusion). It was this plane that Walt
Williams, in our first interview, hinted might reach Mach 2 and
100,000 feet. NACA--I, to be specific--would get a crack at it after
Bridgeman had worked out the bugs. The third Phase Two airplane, the
air-launched jet-rocket combination, had been delivered to NACA in
the fall of 1950, after Bridgeman had made three test air-launches.
No NACA pilot had yet flown this model. This was ship number 945, my
next challenge. In the long run it turned out to be a very useful and
worthy research airplane in the trans-sonic zone, a work horse as
well as a race horse.
On the following day, when I reported to the flight line, lugging
my parachute and crash helmet, the ground crews were ready. The
Skyrocket had already been “mated”--snugged up like a bomb in its
special nesting place in the belly of the B-29 mother plane. The
Skyrocket’s fuel tanks, for both the jet and the rocket engine, were
brimming. The B-29 mother-plane pilot was George Jansen, a top man
for Douglas, and experienced in air-launch. Douglas intended to
keep the mother plane until Bridgeman had checked out the all-rocket
version of the Skyrocket.
I spotted the tanned bald dome of Bill Bridgeman towering above the
knot of men clustered near the boarding ladder of the B-29. He was
dressed in a flying suit. A crash helmet dangled loosely from his
right hand. I walked over.
“You going along, Bill?”
“Yeah. Might be able to help out a little,” he said with that
wonderful friendliness that was his hallmark.
“Fine. Fine.”
We climbed aboard and made our way back to the bomb-bay compartment,
into which the top of the Skyrocket fuselage protruded. The Skyrocket
cockpit canopy was erect. A maze of wires and tubes--the umbilical
cords--was plugged into the back of the Skyrocket, supplying power
from the B-29 en route to the launch point. At the proper time I had
only to climb into the cockpit, close the hatch, and fall away.
Jansen lost no time. Through my earphones in the bomb-bay
compartment, I heard him contact Edwards tower, and the two chase
pilots, Fitzhugh Fulton and John Konrad, both Air Force types.
In the following years, Fulton became something of a legend at
Edwards. I think he must have spent three or four tours at the base,
specializing in mother-plane operations. He launched most of the
rocket pilots and was back again in 1959 to launch me in the X-15.
Soon we were airborne, straining for altitude. I sat beside Bridgeman
on a bench, going through the long pre-flight check-list. At 10,000
feet the crew went on oxygen and I started to board the Skyrocket.
I climbed down into the tiny cockpit, connecting my oxygen hose
to the supply inside the Skyrocket. As Bridgeman towered over me,
helping to cinch up my shoulder harness straps, I wondered how that
long drink of water had ever managed to squeeze into the Skyrocket
cockpit. Bridgeman and the launch operator slammed the canopy shut.
The floodlights inside the bomb-bay compartment spilled through my
windshields, affording enough light for me to see the instrument
panel. At twenty minutes prior to launch, Jansen called the time.
Following an item on the check-list, I lit off the jet engine. This
added thrust would help the B-29 through the thin air and provide the
Skyrocket with flying speed when I dropped.
Now all hands in the air kept a sharp watch for signs of danger. They
could come from a hundred points. At that time we had not yet lost a
rocket-powered airplane, either in the air or on the ground. But it
could happen at any moment--and did, in later months. The B-29s were
something of a problem, too. They were fire-prone.
A few minutes before drop I primed the rocket engines. Chase pilots
Fulton and Konrad, who were flying alongside the B-29 beyond my view,
reported routinely:
“Prime looks good.”
As we bore down over the dry lake at 35,000 feet, seconds before
launch, I glanced one last time at the instrument panels and made
ready. Launching a rocket plane and lighting off the engine properly
is an exacting task. Improper observation of the numerous gauges
and their reactions, or a small mistake in their analysis, can
bring failure, possibly fatal. To gain maximum performance from the
engines--the basic purpose of any research airplane flight--they
should be touched off before the plane has dropped too far into the
thick atmosphere. The plane must also be maintained at a precise
angle of attack. If it noses down too steeply, precious rocket
fuel is expended regaining lost altitude. If the plane is overly
nose-high, the increased drag consumes fuel needlessly.
In theory, the jet-rocket Skyrocket gave the pilot a nice edge.
He could launch with the jet engine going full blast. This would
help him maintain the plane’s equilibrium during the rocket-engine
light-off.
The next sixty seconds were crowded with excitement and frustration.
Jansen, keying his radio mike, droned a brief countdown: “Five ...
four ... three ... two ... one ... DROP.”
I heard a rattle as the two bomb shackles holding the Skyrocket
in its metallic perch were disengaged. Suddenly, then, brilliant
sunlight poured into the Skyrocket cockpit, blinding me. I was
falling like an elevator and flying!
I pulled the nose up and climbed; there was not much time. The jet
engine, fed by scoops that were far too small and inefficient,
would soon starve for want of air. My fingers had flicked across
the separate switches for the four rocket barrels. I felt a gentle
forward surge, indicating a successful light-off. Chase pilot Fulton
drawled on the radio:
“All four going.”
I glanced momentarily at the rocket pressure-gauges. They were in
the green--I think. My eyes were still adjusting to the glare of the
sunlight.
Five ... ten ... fifteen seconds. My Mach meter and altimeter seemed
to be running a clock-like race. Speed: Mach .9 and increasing.
Altitude: 40,000 feet and increasing. My chase planes were far
behind, left in a cloud of rocket dust. Altitude: 43,000 feet.
In the next second, fifteen events--all of them bad--took place
simultaneously. In the first brief instant, I was suddenly thrown
forward against my shoulder straps, almost to the face of the
instrument panel. I heard the jet engines popping crazily, then
the rockets burned out, followed by eerie silence. I knew what had
happened: the balky jet had flamed out; the sudden loss of thrust
had sloshed the rocket fuel forward in the tanks, shutting down all
four barrels. Suddenly my chest felt as though it were supporting the
weight of a platoon of soldiers. The engines were out; cabin pressure
was seeping off. The battery, which should have supplied ship’s power
in the event of engine failure, responded slowly. Everything was out:
radios and electrical instruments.
In that particular airplane, the windshield defogging system was
hooked directly into the electrical system. With no power to supply
defogging air to the windshield, a coat of ice quickly formed,
shutting off my vision. Now the emergency was complete; no power,
no instruments, no cabin pressure, iced-over windshields. Breathing
heavily under the strain of the decompression, I leveled the plane
and then banked until the sun beamed directly on the windshield. I
knew, at least, that I was pointed in the general direction of the
lake, which lay to the west of my position.
By strange coincidence, it happened that the same critical sequence
of events had taken place on Bridgeman’s Skyrocket flight that
morning. When I suddenly left the radio circuit, he guessed
immediately what must be taking place in the Skyrocket cockpit. He
yelled on the radio for chase pilots Fulton and Konrad to pull up and
lock wingtips with my plane--to guide me, if possible, back to the
landing area.
My battery came on the line at last and began to pump power. To
conserve it, I switched off all but the most important instruments.
As I descended, the ice began to thaw and the breathing became
easier. I reached up and scratched a small hole on both sides of the
windshield. Now I could see Fulton and Konrad sitting on my wingtips.
They flew formation on me until 10,000 feet, where the ice became so
slushy that I could brush it off with my hand. I never wore gloves.
Flying a sensitive airplane with gloves is like playing a piano with
gloves.
I brought the Skyrocket in dead-stick and made a normal landing on
Rogers Dry Lake. The mechanics towed the powerless craft to the NACA
hangar with a tractor.
“Scotty,” Walt Williams said later, “if we can just get you through
these first check-out flights, I think we’ve got it made.”