_Smoke in the Cockpit_
Until now, I like to think, the story of the X-15 was in essence
an array of engineering problems without equal or magnitude in the
history of aviation. I have deliberately tried to tell the highlights
of that story in coldly objective terms, the way every engineering
problem should be approached. I have introduced only those elements
pertinent to a full understanding of the flight accounts which
follow, and for the purpose of setting the X-15 in true historical
perspective. Except where it bore directly on the history of the
project, and therefore in some manner influenced our technical
judgment significantly, I have restrained a natural--I should say at
times nearly overwhelming--tendency to inject personal attitudes and
opinions. Some have seeped in, I know, but like the visible portion
of an iceberg, they only hint at what hangs beneath.
Perhaps it would be well if this account of the X-15 could be
continued in an unimpassioned vein. But this would be dishonest. An
objective, well-engineered airplane such as the X-15 is one thing.
But now it is being joined for the ultimate tests with a human being.
The final outcome, then, is the sum product of both, each in one
way or in several ways heavily dependent on the other. To be sure,
mechanical failure could spell spectacular failure; but equally
important is human failure. And thus, I am sure, all that came before
in my life, and everything that _was_ a part of my life during those
months at Edwards--my thoughts, reactions, goals--becomes important
and, for the first time, a vital part of the X-15 story.
From the human standpoint alone there were many incalculable forces
at work, and I have had some difficulty sorting them out in my mind
and attaching the proper weight to each. To begin with, from the
pilot’s view the first flights of the X-15 turned out to be a fierce
challenge. The plane is no toy. After it is launched from the B-52,
every second of flight involves a severe physical and mental exercise
wherein one is completely oblivious of all earthly influence except
the job at hand. Added to this flying challenge is another challenge
accruing through the flow of circumstances. The X-15 has become
an important symbol of our national scientific ability--or lack
of it. A simple mistake could severely tarnish the national image
and grant the Soviets a tangible gain in the cold war. Because the
X-15 had attained this prominence, North American’s prestige as an
aircraft company was laid squarely on the block. Having developed
a deep respect and admiration for the people of that company, I
assumed a special responsibility. Moreover, the success or failure
of the X-15 would directly influence the decision for or against our
much-hoped-for advanced X-15B, the vehicle to which we believed man
should turn next on his path to the stars. Finally, to a great extent
the flights of the X-15, we knew, would have a decisive impact on the
future of all manned combat airplanes, which were then beginning to
be viewed in high councils as less practical as a deterrent than the
ballistic missile, much to our disagreement.
From a strictly personal side, there is still another factor
involved, one which may be more important than all the rest.
Unfortunately, though we try to make it do so, the human mind does
not move from point to point on well-traveled, fairly straight tracks
like a commuter train on schedule. So I cannot, in all honesty, round
out this story as an orderly progression of personal reaction to our
many successes and several near-disasters--to form a neat closing of
the circle. It wasn’t that way at all. As it turned out, a fresh and
vital personal analysis was born in the cockpit of the X-15. Maybe
it was the closing circle focused here which brought it to the fore.
Maybe, as some people are moved to deep thoughts when near the sea,
so I was moved as I stared into space.
As is often the case in life, where nothing is black and white and
thus relatively simple like a mechanical problem, I discovered, like
many before me in dramatic circumstances, that to close one circle is
only to invite another, even larger and more challenging. Or as Ralph
Waldo Emerson put it: “Our life is an apprenticeship to the truth,
that around every circle another can be drawn; that there is no end
in nature, but every end is a beginning; that there is always another
dawn risen on mid-noon, and under every deep a lower deep opens.”
Ironically, the demanding flying of the X-15, which I had so
desperately sought and worked so hard for nine years to achieve, came
as an anticlimax, in a sense. The curve of a new circle was beginning
to form. After thirty-eight years, most of them dedicated to a single
purpose, one I had thought ambitious enough, my thoughts dissolved
into a tumultuous whirlpool of probings and questions. The X-15 was
not enough. But what was the new circle? The search for the answer to
that question paralleled my flights in the X-15 and seemed, at times,
even more demanding.
My daily life was necessarily crowded to the limit with preparations
for flight, or post-flight de-briefings, endless conferences at
North American, or NASA, press interviews, symposiums and technical
gatherings, urgent telephone calls, and what else I cannot remember
now. It seems strange, indeed, but the only place I could find time
for reflection and appraisal--time to probe the meaning of the new
circle--was the X-15 cockpit, during the long, lonely hours I sat
there, strapped in that tiny plane slung beneath the wing of the
B-52. Until then, I had neither time nor inclination to dwell on my
past life. But now I knew it was important to understand it in order
that I could intelligently chart my future.
There was not much time for reflection on the first flight.
Everything was too new and strange. We moved from one semi-crisis to
the next, it seemed.
As we sat, waiting at the end of the long runway while the chase
planes took off and circled, the clock on the instrument panel of the
X-15 showed 0955. I made a note on the tape recorder: the clock’s
second hand was not working. On signal, B-52 pilot Charlie Bock
cobbed the eight jet engines, standing hard on the brake pedal. As
the engines wound up to full military power, the X-15 trembled and
the noise was tremendous. Through my radio earphones I heard Bock
call a countdown for the benefit of the official movie cameramen who
would record every inch of the take-off:
“Five ... four ... three ... two ... one. BRAKE RELEASE.”
One hundred and thirty tons of aluminum, fuel, Inconel X, five men,
and the hope of a nation began rolling down the long runway. Success
or failure of this first take-off was now entirely up to Charlie
Bock. I was simply a first-class passenger, occupying a private
compartment out on the wing. Without flaps to give added lift to
the B-52, the take-off roll would be unusually long, the lift-off a
ticklish maneuver requiring a delicate pivotal movement on the rear
landing-gear truck of the B-52, a sudden and severe raising of the
nose.
The greatest point of concern was the predicted, possibly destructive
vibration the X-15 external store might impose on the B-52. A hundred
times in the past, Bock and I had reviewed corrective procedures to
follow if this should happen. We knew it would take 190 knots to
get the B-52 and its load into the air. We agreed that if severe
vibration developed during the take-off roll before he reached 170
knots, he would chop the B-52 throttles and abort the take-off.
But if no vibration set in up to 170 knots, he would continue
the take-off, climbing out. If during the climb at 260 knots the
vibration rose to a degree that seriously endangered the bomber, we
agreed that the X-15 must be jettisoned without delay. I would have
a few seconds warning--time enough to start the APUs and shift from
B-52 electrical power to X-15 power. Then I would attempt to glide
the X-15 in dead-stick. We plotted the take-off so that I would have
a fairly good shot at the lake bed in this event, but we both knew
that our scheme was pretty marginal--impossible, in fact--below
15,000 feet. In other words, if cut loose below that altitude, it
was most unlikely that I could reach the lake bed. I would try. If
I failed, I could always bail out at the last second. The important
thing was to separate the X-15 from the mother ship. There were four
men aboard that airplane. There was one in the X-15.
As we rolled, the huge runway distance markers flashed by, clocking
our path: 14,000 ... 13,000 ... 12,000 ... 8,000. When the X-15
air-speed indicator reached 170 knots, I noted only a minor
vibration. We would continue the take-off. 6,000 ... 5,000 ... 4,000,
and we broke ground. It was smooth and gentle, like the take-off of
an airliner. The air-speed indicator needle crept up to 260 knots.
The parched brown desert fell away rapidly. The vibration did not
increase.
My eyes were fixed now on a small but ominous trickle of water slowly
filming between the two layers of windshield glass in the X-15. It
was water which had accumulated in the insulation out in the open
during the long weeks of ground tests on the APUs. Who could have
guessed this would happen on the dry desert? The nitrogen defogging
gas flowing between the layers was designed to keep it clear under
ordinary flight conditions. But I knew it would not be sufficient to
check the vapor accumulation of three months of exposure to the rain
and night dampness. Already a faint haze, the first sign of ice, was
forming on the right panel.
Charlie Bock spoke on the radio:
“We’re at three thousand feet now. I’m going to throttle back on
number five and six engines.” Slowing these two engines on the pod
nearest me would reduce the noise and some of the vibration on the
X-15. Even with two engines idling, the giant jet bomber gained
altitude rapidly, circling Rogers Dry Lake.
By the time we reached 15,000 feet both windshields of the X-15 were
solidly iced over, recalling those early days at Edwards when I
faced an iced windshield in the X-1 and the Skyrocket. An emergency
launch was feasible. But an emergency dead-stick landing with iced
windshields would be tough, to say the least. I might make it, I
thought, if I blew the canopy. I made a mental note _never_ to go
aloft again in the X-15 without a plastic windshield scraper. (Later
this item was installed on the X-15’s instrument panel.)
The three chase planes tucked in close, and our $60 million space
task force bore skyward. There was not much noise beyond a steady
hum and some static on the radio circuit. We were all--the men in
the B-52, I in the X-15, Q. C. Harvey and the others on the ground,
and the chase pilots nearby--leafing our way simultaneously through
the thirty-page flight check-list. Occasionally Q.C. spoke: “Going
to item 39-A.” Or I would say: “Item 43 completed, going to item
44.” Charlie Bock put the B-52 through several stiff banks and turns
to check vibration and X-15 mating. I followed these maneuvers on
my instrument panel. Everything was going better than any of us had
dared expect.
Then, as on every subsequent flight of the X-15, we prepared for a
dress rehearsal of an actual air-launch. Since there were no rocket
propellants aboard on this first trip, we would eliminate an engine
prime. Except for this one step, it would be a realistic “dry run,”
which would give us much-needed practice for the real thing and an
opportunity to test the systems as well. Especially the temperamental
APUs.
Like the X-15, the Clark full-pressure suit, designed to protect
the pilot in the event the cockpit pressurization failed, was also
undergoing its first realistic test. Thus we planned each flight to
give the suit a chance to show what it could do. The cockpit of the
X-15 was designed to be pressurized “down” to 35,000 feet. The suit
was designed to go into operation if it sensed that the pressure
in the cockpit rose “above” 35,000 feet. Thus if we left open a
connection between the outside air and the cockpit and flew above
35,000 feet, the cockpit would fail to pressurize and the suit would
automatically go into action at slightly above 35,000 feet. This
connection between the cockpit and the outside air was called the
“ram-air door.” We simply left it open on the climb to altitude and
during the full-pressure suit experiment.
When we passed 30,000 feet both windshields were thick with ice.
However, I could still see the instrument panel: it was brilliantly
lighted by two strong thunderstorm flood lamps beamed over my
shoulders. Every five minutes I turned a switch which automatically
recorded all the gauge readings within the cockpit and at certain
key positions throughout the airplane, and I reported on the radio
circuit: “Data burst.” In addition, I kept a running log of gauge
readings on my portable tape recorder, along with some private,
personal observations.
At 35,000 feet, with the ram-air door open, I felt the Clark suit
pressurize. The link-net material seized me on all parts of my
body. From that point on my movements were slightly constrained
and slightly awkward, although not nearly so awkward as a deep-sea
diver’s.
Satisfied with the test, I strained forward at 38,000 feet to grab
a lever between my legs, the hardest piece of equipment in the
cockpit to reach. The lever operated the ram-air door. Grunting and
puffing, trying to get a good grip on the lever with my glove, I
finally pulled it shut. As soon as the outside air was closed off,
the nitrogen gas began to build up inside the cockpit, pressurizing
it back “down” to 35,000 feet. When the cockpit altitude stabilized
at 35,000 feet, the pressure suit relaxed its grip and once again I
could move my arms and legs with ease.
Now still at 38,000 feet we began final preparations for the mock
launch. Assuming everything else is going well, that is to say
that the fuel-tank gauges (which we were not concerned with on
that flight) are in the green, the big step is to make the X-15
independent of the B-52 with its own electrical and control power. It
was a crucial moment: the first airborne test of the X-15’s heart,
the electrical and hydraulic power source, the APUs. I flicked a
switch to start these units, keeping a close eye on various gauges
that would tell me if all was well in this department.
When the APU turbines turned up, I could hear a faint whirring
noise inside the X-15 cockpit. So far, so good. The turbine bearing
temperatures, a critical factor and frequent cause of breakdown, were
within normal range. Then I turned a switch which should have put
number one generator on the line. It failed. I tried to bring number
two generator to life. Again no luck. I recycled both, trying to
shift from B-52 to X-15 power source. Hopeless. The APU turbines were
turning up, but the generators for each were out of commission. With
iced windshields, if Bock had to cut me loose, I would have to bail
out. The X-15 would have hydraulic control power essential to flight,
but no electrical power for instruments essential to “blind” flight.
I cursed to myself, and then on the radio called: “Q.C., I can’t get
the generators on the line.”
“Okay, Scotty. Lets move on to the next item,” Q.C. replied.
This was a visual check of the X-15 controls--rudder, aileron,
elevators--and flaps. I horsed on the stick and kicked the rudder
pedals, following detailed instructions on the check-list. The
chase-plane pilots reported control response. Good.
Just about then I noticed a thin wisp of smoke curling up between my
legs. Impossible! I thought. We couldn’t have a fire in the cockpit;
it was completely sealed off, pressurized with inert nitrogen. No
fire could possibly burn in that space. The only answer was that
some wire must have overheated, smoldering the insulation. The smoke
thickened.
“Q.C.,” I reported. “I’ve got a little smoke in the cockpit. Nothing
serious. Must be a hot wire some place.”
“Okay, Scotty,” Q.C. responded quietly.
These, I learned later, were anxious moments at Edwards. But I was
not overly concerned. Except for the APU hydrogen peroxide, the X-15
was empty of its usual load of volatile fuels, and the chances of a
serious fire or catastrophic explosion were negligible. Besides, what
could I do about it? If it came, it came. I had no generators, no
vision. If a bad fire developed, we’d have to cut loose and I’d bail
out. In any case, the plane would be lost.
When the smoke in the cockpit became so dense that I could no longer
see the instrument panel nor observe any test intelligently, I spoke
quietly to Charlie Bock:
“Let’s go home.”
Q.C. broke in:
“On the descent make a test of the X-15 gear.”
“Okay, Q.C.”
At 15,000 feet the chase planes moved in close. I pulled the gear
handle. The telescoped nose wheel, extended by a ballistic charge,
snapped into position with a jolt that felt like a swift kick in the
behind. When the two rear skids popped down satisfactorily, chase
reported gear okay. Since the gear cannot be retracted again, we left
it in place as the B-52 lined up on final. Automatic movie cameras
mounted on the side of the B-52 and hand-held cameras in the chase
planes recorded all these drills. The smoke in the cockpit was pretty
thick, and I noticed a new and heavy vibration somewhere in the rear
of the X-15. What was that? It was too late to find out; we were
committed.
Landing the B-52 with its external store and no flaps was no cinch.
But I could see that Bock and Allavie were already practiced artists.
They brought the giant plane in very nose-high and greased in on the
rear gear-truck, one hour and ten minutes after take-off. Then the
nose fell forward heavily and we began the roll-out, long, easy, with
the X-15 rear skids almost touching the runway. If something happened
on landing--such as a crash and fire--I was in the safest possible
place. Sealed inside a cockpit designed to withstand 1200 degrees
Fahrenheit, I would just wait until the men put out the fire and then
open my canopy. If the heat became unbearable, I could always eject
right on the ground.
When the B-52 stopped rolling, I opened the X-15 canopy. Dense smoke
billowed forth, greatly and unnecessarily exciting the firemen. They
rushed in with trucks and sprayed the rear of the X-15 with water.
But there was no fire, as such, to put out. The smoke was caused
when one of the APU generators seized in flight and burned up. As we
discovered later, the generator was a mass of ashes. The fact that
the smoke had seeped into the cockpit turned out to be a blessing
in disguise. It revealed that under certain circumstances the
protection of the cockpit was compromised. This was quickly corrected.
Bock taxied the B-52 back to the mating area. The groundmen
skillfully directed the parking so that the X-15 hung directly over
her hydraulic lifting jacks used to lower the ship from the pylon.
They shoved the steel work platform against the nose and Mel Beach
climbed up and removed my helmet. I wriggled out of the cockpit and
chatted with Stormy and Charlie Feltz for a few moments, trying to
puzzle out the smoke in the cockpit, and then I walked somewhat
wearily over to the 16th Physiological Training Flight van.
Inside, to cool off, I quickly removed the top layer of my pressure
suit, and then washed the perspiration from my face and hands. When I
turned for a towel, Captain Richardson was standing there. He handed
me a martini--a real martini, with an olive. It was the perfect
touch. I wished that our first flight in the X-15 had been as perfect.