_The Old Pro_
On the morning of September 17 the weather at Edwards was as blustery
as it usually is in the rainy season in December. There was a heavy
cloud layer hovering near the edge of the base. The winds on the lake
bed were gusting to twenty and twenty-five miles an hour. But as I
have said, landings are my strong point. Crosswinds have never kept
me on the ground. On that day I don’t think anything could have kept
me on the ground. “Let’s go,” I said to Stormy and Charlie Feltz.
And we did.
Bock lifted the B-52 off the runway at precisely 0730. Major Bob
White, Joe Walker, and Al White, the North American X-15 back-up
pilot, flew chase. Of the forty critical gauges on the X-15 panel,
only one was out of line. The nitrogen gas supply for the equipment
that cooled the electronics gear was sagging. When I called the gauge
readings to Q.C., I deliberately skipped this one. After four years I
knew intimately the requirements of each system. I had three limiting
figures in mind: the specification figure, which was conservative;
our agreed-upon “no go” realistic figure, less conservative, and one
which Harvey must cancel on; and then I had my own absolute minimum
that I knew would not endanger the X-15 (after all, the final
decision is the pilot’s). Today we were going to _fly_.
At 0756 Bill Berkowitz switched on the Lox top-off. This time it did
not fail. We moved into a launch rehearsal.
Q. C. Harvey spoke from the ground: “Okay--let’s go ahead.”
“We’re in good shape,” I said. We were--all but the coolant nitrogen.
Charlie Bock called the ten-minute warning. Q.C. reported the cloud
front holding stationary. The lake bed was clear.
* * * * *
Watching the creeping rate on the nitrogen pressure, I made up
my mind we could be committed without hazard. I made last-minute
preparations to fly, zipping through the lengthy check-list fixed to
my knee-pad. At six minutes to launch I started the APUs. At five
minutes to launch I released the pressure to the main tanks. The
helium regulator worked beautifully. At four minutes to launch I
checked the jettison system. I started the fuel-line purge and opened
the main fuel shut-off valves. The pre-heat lights came on green.
Suddenly I heard a familiar--and ominous--clanking. The Lox tank
safety vent had popped. I thought, here we go again. I sang out
on the radio: “Hold the phone.” Too much pressure had built up
in the Lox tank. I held my breath momentarily, watching the Lox
tank-pressure gauge. It dropped off slowly and the vent reset
properly. The Lox tank regulator had a slow leak. I timed the
pressure cycles and decided it was acceptable.
“Okay,” I said. Bock resumed the countdown.
At the one-minute warning we shut off power and oxygen from the
B-52 and the X-15 was in effect “on its own.” I turned on the
rocket-engine master switch and started the prime of fuel and Lox
through the engines. Then I rolled the automatic photorecorders,
which would keep a concise record of all events in the X-15. Finally
I flashed the green launch-light for the second time on Bock’s panel.
“Ready to go,” I said.
Bock called the brief countdown: “Three ... Two ... One ... DROP!”
For the second time in eight flights I fell away from the B-52 pylon
into open sky. My left hand felt the toggle switches which would
light two barrels of the lower motor. I flicked them as soon as I
heard the “kerchunk” of the shackles releasing the X-15. In less than
five seconds my hand moved to the other six toggles, and before I had
dropped 2,000 feet I was able to report: “Got eight of ’em going.”
On the earlier rocket planes we felt a push, like a gentle kick in
the rump when we lit the rockets. We would feel a much greater push
when the 57,000-pound thrust XLR-99 engine was installed. With the
smaller X-1-type engines, the heavy X-15 responded rather slowly. The
effect is somewhat like opening the throttle on a jet airplane.
I fell to about 33,000 feet before the rocket took hold and began
pushing the X-15. I reported: “Going uphill at 33,000.” I added:
“Looks good across the board.” It _was_ good--even the helium
pressure, which was still within my absolute limit.
Since the X-15 has no compass and I cannot see the horizon during the
steep climb, I had to rely on Bock during the first few seconds for
a steer. He reported I was to his right. The F-104 chase planes were
now flying wide open. I soon left them in a cloud of vaporish white
rocket exhaust.
Pushed by the eight flaming barrels the X-15 suddenly became a
tiny thing of immense power and speed darting across the deep blue
desert sky. Had it not been for my exhaust trail the observers on
the ground could not have followed my course except by radar. More
at ease now after a successful light-off, I directed my attention to
these questions: Did we have a stable airplane? Was it dangerous or
difficult to fly? Were the controls now adequate?
It was apparent almost instantly that we had built a beautiful
airplane. Her nose held straight and firm without the yaw and pitch
common to most high-performance planes. As I blasted toward the
heavens I alternated between sidearm control and the center stick,
pumping in tentative control motions to feel her out. She remained
sound and stable. Because she is long and slim and has stubby
wings, she was extremely sensitive when I rolled her. But this we
had anticipated and it was no surprise. The plane eased through
the speed of sound imperceptibly with little or none of the usual
buffet-and-control disturbance.
As I was nearing 50,000 feet I was startled to hear a loud buzzing.
What could it be? My first thought was that an APU unit was
vibrating. But a glance at the gauges indicated they were running
perfectly. It was not until later that I discovered the source of the
noise. The cockpit of the X-15 is so small that when I lean forward
to reach some of the controls my helmet wedges in the V-shaped canopy
glass. The noise I heard was caused by the normal, healthy vibration
of the X-15 machinery. My helmet, which is a kind of sound chamber,
magnified this vibration manifold. I called this noise on the radio
to my subsequent regret. All the vibration experts in the country
have had a field day trying to solve this one. It would never have
been noticed had not my helmet touched.
Two minutes after launch I reached 50,000 feet and pushed over in
level flight. Then I dropped the nose slightly for a speed run,
meanwhile maneuvering the ship through a series of turns and rolls,
conscious of the deep rumbling noise of the rocket and a great rush
of wind on the fuselage. It was obvious the black bird was in her
element at supersonic speeds. She responded beautifully. I stared in
fascination at the Mach meter which climbed quickly from 1.5 Mach
to 1.8 Mach and then effortlessly to my top speed for this flight
of 2.3 Mach or about 1,500 miles an hour. Then, because I was under
orders not to take the X-15 wide open, I shut off three of the rocket
barrels. As I slowed down, I recalled the agony at Edwards many years
before when we had worked for months pushing, calculating, polishing,
and who knows what else to achieve Mach 2 in the Skyrocket. Now with
the X-15 we had reached that speed in three minutes on our first
powered flight and I had to throttle back.
About four minutes (230 seconds, to be precise) after launch, the
fuel tanks ran dry and the engines shut down. I got set for the
fast dead-stick landing. As I swung into a turn to line up with the
lake, the X-15’s wedge-shaped tail bit the air and the nose turned
sharply, causing me to comment on the radio: “Very powerful rudders
on this little baby.”
My altitude was dropping off rapidly. But now, with a total of nine
or ten minutes flight time in the ship, including the first glide
flight, I had complete confidence in her. I had probed her weaknesses
and strengths and knew what would please her or make her angry.
Routinely I called for a re-check of the winds on the lake bed. A
comical exchange, no doubt arising from the tension on the ground,
followed.
Sam Richter, parked on the lake in his van, consulted the readings
from his anemometer and reported the winds as “four knots.”
At the same moment Edwards tower reported the winds as “eighteen
knots.”
“Repeat, please,” I said. The lake was growing larger by the second.
I could see Sam’s van, parked in the row of emergency vehicles. A
crosswind of four knots was no problem. But a crosswind of eighteen
knots required sharp attention at touchdown.
Sam came back: “Four, repeat four, knots.”
Edwards tower broke in: “Eighteen, repeat eighteen, knots.”
Then on the radio circuit Sam and the Edwards tower lapsed into a
debate about the winds. To relieve the mounting tension, I broke in:
“Sambo, why don’t you stick your head out of the van and see how bad
the winds are?”
Sam stuck by his four-knot figure. Since he was stationed nearest
the landing strip, though still several miles away, I accepted
his estimate and lined up on the north-south runway, disregarding
crosswinds. By now my chase pilots, Bob White and Joe Walker, had
found me and were glued to my wingtips.
The winds at Edwards are often very variable and Edwards tower, it
turned out, had correctly estimated them for my landing area. They
were very strong from the west. When this fact was established, I
was advised to shift to the east-west runway. But it was too late.
The X-15, “gliding like a brick,” was already too close to the
ground. The men, concerned mainly for my personal safety, were still
cluttering up the air with their debate. I cut them off sharply:
“I’m committed. Let the chase have the radio.”
During the turn on base leg I droned the readings on the panel
gauges. I read off the APU bearing temperature as a disastrous 1700
degrees instead of 170, which is normal. Hearing this on the ground,
Charlie Feltz nearly fell dead. He shouted at Sam: “Wha’d he say?
Wha’d he say?” I quickly reassured him.
My speed fell off to 250 miles an hour when I crossed the edge of
the lake bed and I blew off the ventral fin. Just at that moment I
thought I heard chase Bob White report his plane had run into the
fin. This would have been catastrophic.
I was concerned. With only a few seconds remaining before the X-15
would touch down on the lake, I spoke into the radio: “You fouled the
tail?”
“No,” White replied. “The chute fouled. It failed to open.” It was a
minor matter. Anyway, the chute did open a split second later. White
dutifully reported this fact with the additional comment, “Isn’t that
nice?”
I was now beginning to feel the strong crosswind. To compensate, I
aimed the X-15 cross the marked lake-bed runway. My hope was that I
would drift over between the black lines by touchdown. I commented on
the radio: “That’s a pretty good crosswind.”
Chase White, who was “talking” me down, said: “Very nice.” As a
matter of fact, the ship was flying smoothly. There was no sign of
the violent porpoising I had experienced on the first glide flight.
I held the nose high and seconds before touchdown, at 200 miles an
hour, dropped the rear steel skids and nose wheel and flipped the
flap switch.
Exactly ten minutes from launch by the X-15 clock the skids dug into
the hard-packed surface and almost instantly the nose fell heavily,
cushioned by the nose wheel. White repeated: “Very nice.” As we
skidded along throwing up dust, I joked: “What do you expect from the
old pro, Daddy-O?”
This comment was typical of the radio repartee of fighter pilots, who
by nature will admit to no limitations whatever. With God’s help I
had accomplished my mission as I was sure I would; the X-15 and I had
not failed our friends, associates or, if you will, the nation. It
was a great pleasure to confirm this triumph to myself. Involuntarily
I voiced my feelings on the radio.
At that moment I became aware of a new danger looming in my path.
The crosswind was stronger than I thought and the ship did not drift
over onto the marked runway as I expected. I touched down outside
the right boundary line and skidded at 150 miles an hour directly
toward a deep drainage ditch about a mile ahead. If I coasted into
that ditch, I knew that I could very well wipe out the X-15’s landing
gear or possibly damage the plane more seriously. The old pro, now
feeling sheepish, pushed hard on the rudder pedal, hit the speed
brakes, and dropped the elevators full down, desperately trying to
steer the plane to the left and stop it all at once, to avoid another
F-100 through the hangar wall. I snapped into the radio: “Hollered
too soon, didn’t I? I’m going to coast into that ditch.” I thought:
that’s the way it will always be at Edwards--hero one minute, bum the
next.
As it turned out, I was only fifty feet off the marks and fortunately
stopped a hundred yards short of the ditch.
After reporting with relief to Q. C. Harvey, who could no longer
see the X-15, that everything was okay, I tried to open the canopy,
but the release was stuck fast. While waiting for the ground crews
to arrive and let me out, I proceeded with the post-flight chores,
shutting down various systems and taking final readings. The decision
on the coolant gas had been right and all systems looked good.
Unknown to me, a new and far more serious crisis was developing
in the X-15. A pump casing had ruptured. Alcohol was flowing into
the after engine bay and a furious though not yet visible fire had
broken out. We later calculated that it started just after I blew the
ventral, when I was still fifty feet in the air.
Sam Richter and Charlie Feltz arrived with the fire trucks, official
observers, and ground-support equipment. The crewmen opened the
canopy from the outside and removed my helmet. I climbed out into the
stiff desert breeze to meet half a dozen outstretched hands.
Our mutual admiration society was in full flower when Sam spotted
the fire. Dismayed, we all ran to look. Sam waved the fire trucks
toward the tail section. The firemen unreeled the hoses and showered
the tail section with fog. There was still a considerable quantity
of alcohol on board. The X-15 at that moment was like a bomb with
a lighted fuse. We chased the official observers back while the
firemen, with no display of concern for their personal safety, put
out the fire.
When I got a close look at the rear of the plane I realized again for
the millionth time over the past twenty years that airplanes are not
for the impatient. We would have to retrench and try again and again.
The fire had burned through a large area, melting aluminum tubing,
fuel lines, valves, and other machinery. Before the X-15 could fly
again I knew we would have to rebuild the damaged section completely,
and it would take time.
The fire was one more delay. The plane was built for the specific
purpose of ferreting out such weaknesses. Our job was to correct
these weaknesses one by one until an irreducible minimum remained, so
that we could then move ahead. The X-15 was earning her way showing
us how to advance. There was a little matter, however, for which we
could all be thankful; if the alcohol fire had broken out one minute
earlier, it is quite likely that the X-15 and the pro at the controls
would have been blown to oblivion.