_The Reluctant Dragon_
At 0730 on April 1, I climbed into the X-15 cockpit, ready for a
second “captive” flight. Although we had learned a great deal on the
first, none of us felt the ship was quite ready for a free glide
to earth. First, we would make another dry run, to be sure. In the
intervening two weeks we had made many improvements on the X-15.
The temperamental APUs had been pulled out, rebuilt, and tested in
repeated “runs” on the ground. We had removed the canopy and baked
it in a hot oven for hours to purge it of the water trapped in the
insulation, and then waterproofed it. As a further precaution against
windshield icing, the nitrogen defogging gas was routinely turned on
three hours prior to take-off. By Stormy’s edict, we had installed
a radio intercom between the X-15 and B-52, which would, in theory,
keep a line of communication open to me, if the single X-15 radio
transmitter conked out at a crucial moment.
As usual, there were some pre-take-off delays. The men swarmed about
the fuselage of the X-15, pulling wires and making last-minute
repairs which were checked and rechecked by the ground service cart
operators. The X-15 panel was alive. I sat staring at the lights and
gauges looking for signs of trouble. By that time I had spent at
least three hundred hours in that cockpit and I could sense a fault
or impending crisis almost subconsciously.
At 0812 Oscar Freeman and Pete Barker slammed the X-15 canopy shut.
Charlie Bock and Jack Allavie wheeled the giant mother plane to the
take-off runway and cobbed the engines. At 0844 the wheels left the
ground and we were airborne for the second time. I tested the new
intercom (unsatisfactory) and droned off the gauge readings, making
a “data burst” every five minutes. At 25,000 feet altitude the X-15
radio transmitter and receiver, perhaps because of the intercom
modification, faded drastically. But the windshield remained clear.
The chase moved in close and we droned skyward for a launch rehearsal.
At 25,000 feet altitude, I could faintly hear Q. C. Harvey come on
the radio circuit: “I guess we’ll have to abort. I can’t hear Scotty.
His radio is out.”
I already had the transmitter on, but the amplifiers were not putting
out. Breaking a long-standing personal rule, I shouted as loud as I
could over the radio mike: “No, Q.C. No. No. Don’t abort. No abort.”
“Okay, Scotty,” Q.C. replied. “I can just barely hear you, very faint
and intermittent.” Determined that a simple radio malfunction would
not stop the test, I shouted myself hoarse. Then Q.C. came up with an
ingenious, spur-of-the-moment solution to our radio difficulty.
“I can hear your mike loud and clear when you key it, Scotty. But I
can’t hear your voice. We’ll follow a system here. You key your mike
in response to my questions. One dick means yes. Two clicks mean no.
Okay?”
I keyed the mike one click.
Following this system, we worked through the thirty-page flight
check-list with Q.C. in command on the ground. “Okay, Scott,” he
would say. “We have completed item 10. Are you ready to go to item
11? Repeat, are you ready to go to item 11?” If I was satisfied, I
responded with one click of the mike. If I did not think the ship
was ready for the next item, I transmitted two clicks. Slowly we
accumulated the necessary data, which included various severe
maneuvers of the B-52, a carefully monitored speed run to check the
X-15’s air-speed indicator, and finally the big item, the launch
rehearsal. The APUs came on the line and held steady, purring like
kittens.
Taking advantage of our good luck, we circled Edwards for well over
an hour and a half. When I noted the coolant for the APU bearings was
getting dangerously low, I waved my hand at the B-52, suggesting we
return to base and land. Bill Berkowitz, the launch-panel operator,
watching the X-15 through a closed-circuit television installation,
caught the signal and relayed my request by radio to the ground. Q.C.
came on the line:
“You want to land, Scott. Correct?”
I keyed the mike one dick, and Charlie Bock banked toward the Edwards
runway. We dropped the X-15 gear for a routine test, and shortly
thereafter Bock greased on, one hour and forty-four minutes after
take-off.
* * * * *
Except for the simple radio failure, the X-15 had performed well
on this flight. But the full-pressure suit had not. The seals were
leaking, and the valves failing. In fact, in the post-flight report,
I noted thirteen discrepancies in the suit and asked that the Clark
company send a team to Edwards without delay to make the necessary
modifications and adjustments. With all our tests on the ground and
in the air, we were wearing the suit out. On one of the hundreds of
ground tests I nearly killed myself.
It happened right in the X-15 cockpit while the canopy was open.
Decked out in the suit and helmet, I was running a test which
involved innumerable selections of oxygen supply, on, off, on B-52,
on X-15, etc. I made an error and got out of sequence. I proceeded
with the test, breathing not X-15 oxygen as I supposed, but the
nitrogen gas suit coolant which was leaking into the helmet through
a crack in a rubber seal. There were several ground crewmen working
about the X-15, and Pete Barker was bending down in the cockpit
helping me with the test. Nobody was aware of the developing crisis.
Nitrogen gas is an insidious suffocant. Man cannot long survive
breathing only nitrogen. Quite soon I began to feel its effect.
The instrument panel facing me seemed to be floating away. I gazed
in wonder at this phenomenon for several seconds, too stupefied to
realize my predicament, then I drifted off into unconsciousness.
Barker, working with me on the test, still had no inkling of the
danger.
By the grace of God I suddenly snapped back into momentary
consciousness. Bewildered, I sought to escape from my slow
suffocation. Not knowing what caused the blackout and dizziness, and
unable to think clearly, I was desperate. I clawed helplessly at the
fittings of my helmet, and then cast up my arms in one final protest
and, as I recall it dimly, probably yelled.
Luckily for me, Barker saw me raise my hands and sensed trouble. He
jerked off the helmet in the nick of time. I feel I owe my life to
his quick response.
* * * * *
On the evening before an X-15 flight was scheduled, Stormy always
came up to the desert for a last-minute look-see. He checked in at
the North American hangar, talked to the X-15 mechanics, and toured
the mating area, where the men were working to attach the X-15 to the
mother plane and to check out the systems. When Stormy was satisfied,
the two of us slipped away and drove far down the desert to a remote
roadside restaurant, where we could lay plans during dinner without
interruption. On April 13, the eve of the third flight, Stormy was
restless and quietly angry. He was involved in a tight poker game
with high stakes. Like all the rest of us, he wanted to see the
X-15 fly--and the sooner the better. But we knew that if we pushed
too hard and fast and something catastrophic happened, the country
would suffer a black eye and we and the company would be severely
criticized. At the same time, if we didn’t show more promise, we
would be chided for dragging our feet. Thus Stormy--all of us in
fact--was seeking to strike a balance between fast action and sound
technical advance. Ridiculously petty items were sabotaging us: APU
regulators, radio intercom wiring, two-dollar valves--horseshoe nails
that could conceivably lose us a kingdom. Each time we aborted a
flight we lost two weeks, the time it took to “turn around” the X-15
or prepare it for a new trip into the air.
Stormy is one of the few men I have met in my life whom I sincerely
admire. I like his approach to building airplanes. He is not only
enthusiastic and eloquent in presenting his case for this or that
airplane, but also he is more technically honest than any engineer
I have ever known. If something doesn’t work, it doesn’t work,
and it is discarded. He doesn’t prolong it, building an empire of
paper-pushers. He knows how to take on a job and do it right. And
once he begins, he is completely objective and ruthless about it.
“We’ll play it like this,” Stormy said. “Tomorrow we’ll go through
rehearsal. If the APUs look okay, go through another rehearsal. If
everything seems to be going well, then we’ll drop. But wait for the
word from me. The final decision to drop, of course, is yours.”
* * * * *
Just after dawn the following morning I climbed in the X-15 cockpit
and droned the gauge readings into my portable tape recorder: “Liquid
nitrogen source 3700. Number one hydraulic temperature 18 degrees.
Number two hydraulic temperature 5 degrees. Number one APU source
pressure 3500. Number two APU source pressure 3500....” As far as the
X-15 was concerned, everything was near-normal. Except for a radio
line in the helmet, which was snagging on the neck seal, the Clark
suit was working well. It had been completely overhauled in the past
ten days by Clark’s experts.
After reading the gauges I stared at the instrument panel, waiting
for the ground crews to seal up. Stormy, wearing a gabardine
topcoat, was huddled with Q. C. Harvey and Sam Richter next to the
communications van.
At 0823 Charlie Bock released the B-52 brakes and we rolled down the
runway to begin the third X-15 flight. When the B-52’s wheels lifted
off, the three circling chase planes squeezed in close and climbed
out toward what I hoped would be, by Stormy’s decision, our first
launch. I was anxious and eager. By then we had been grooming the
airplane for five months. To gain added X-15 performance, the launch
altitude was raised from 38,000 to 45,000 feet. It took almost an
hour to reach peak altitude.
After the usual checks of the pressure suit, the X-15 cabin
pressurization, and some special B-52 speed-tests and maneuvers to
feel out the “mating” at that extreme height, we proceeded to the
first launch rehearsal. Everything worked perfectly--almost. Radio
communications were good, and the APUs came on the line with no
trouble, although we expected trouble at higher altitude where the
temperature is colder. I deliberately opened the ram-air door to try
to fog the windshield. It remained clear. We simulated a drop and
closed down. Then Bock wheeled the B-52 through a gigantic ten-mile
turn high in the sky to repeat the rehearsal. The chase planes,
hanging in the thin air at reduced speed, struggled to keep position.
Our path through the sky was marked by seven white contrails.
For the second time on that flight we moved in to a launch rehearsal.
I started the APUs again, anxiously awaiting the key words from
Stormy on the ground. But Stormy, who was watching and listening at
Sam Richter’s truck out on the lake bed, didn’t say a word on the
radio. His intuition told him the time was not ripe. With no positive
word from him we continued the launch rehearsal and at one minute
before drop time aborted the flight. I was quite disappointed.
As a matter of routine, after launch rehearsal on the descent to
Edwards, I kept the APUs on, so that the X-15 would have power in the
unlikely event that an emergency arose and Charlie Bock had to cut me
loose in a hurry. The APUs were still running as we descended through
42,000 feet. At 41,000 feet both APU generators suddenly dropped off
the line. I recycled number one and got it back on, but number two
refused to connect. I reported this by radio.
A few seconds later I became aware of an ominous, heavy vibration
somewhere in the after end of the X-15. Something was quite wrong.
My eyes automatically swept across the gauges; my ears tuned to the
growing rumbling. Number two APU had failed. I was not aware of the
full extent of the malfunction then, but I knew it was serious. Later
we discovered that the unit had seized and shaken completely off
the mounts. This severe wrench also disturbed the second APU. I shut
both units off, thankful then that Stormy’s intuition was working. A
minute later I noted a wisp of smoke in the cockpit.
This time there was no connection between the APU failure and the
smoke. A wire in one of the cabin blowers simply overheated and
caused the insulation to smolder. I was tempted to ignore the smoke
because nothing strikes fear in the hearts of the ground people quite
so rapidly and decisively as smoke or fire in a rocket airplane.
But one of my duties as test pilot was to report _every_ routine
and non-routine event in the X-15 cockpit. Reluctantly I passed the
word on the radio circuit and, as expected, there was quite a bit of
excitement on the ground. But the smoke diminished and by the time we
reached the ground, an hour and nineteen minutes after take-off, it
had disappeared altogether.
When we parked in the mating area, the ground mechanics opened the
doors on the APU access compartment almost immediately. Charlie
Feltz, Stormy, and I peered in at the shambles of metal that had once
been two highly refined, critical pieces of X-15 machinery. The APUs
at that point had been under laboratory and field test for a whole
year, yet they were still obviously a long way from being reliable.
Sick with disappointment, Stormy hurried off to Los Angeles to set
in motion words and action that soon solved the X-15 APU problem. I
don’t know how much money and time were spent in the extensive APU
rebuilding and testing that followed in the next few weeks, but I do
know that with one exception in the year that followed we had no more
APU trouble.
These APU problems, which I probably have dwelt upon at too great
length, were not confined exclusively to the X-15 rocket airplane.
Other companies were having much the same kind of trouble in
ballistic missiles. At Cape Canaveral scores of multi-million-dollar
birds blew up on the pads or in flight because of APU failure. This
is one part of the price of progress, of probing into the unknown.
The big advantage in the X-15 was that we did not lose our bird.
With a pilot at the controls we were able to detect and avert fatal
trouble, and save the ship for another flight. We could bring
the broken APUs back to earth in one piece--or sometimes in one
piece--for engineering analysis. The fixes we made, I hope, were
passed on to the missiles at Cape Canaveral. Thus in one sense the
X-15 was already beginning to pay its way as a research tool.
After the flight Captain Richardson was waiting in the 16th
Physiological Training Unit van with the usual martini. It tasted
weak. I commented on this while squirming out of the pressure suit.
“It’s watered down,” Richardson said.
“What?”
“That’s right. If you can’t pull off a full-blown flight, you don’t
get a full-blown martini.”
Ribbing of this kind was directed toward us from many official
sources. Our tiger was gaining a reputation for being a Reluctant
Dragon. This hurt in more ways than I can remember.
* * * * *
21 May, 1959. Thirty-one weeks had flown by since we trucked X-15
number one to the Edwards test base. Seventy-two days since our
first shaky captive flight in the airplane. Forty-one days since
captive flight number three. NASA and the Air Force were becoming
increasingly anxious and no longer hiding it. Our saga of troubles
had stung the X-15 flight-test team badly. Every man felt a personal
responsibility. Each worked with an intensity and devotion that no
amount of money could buy, and at last we were ready to go into the
air once again. This time there was no talk of a drop. Our sole
objective was to stage a completely successful captive test, to prove
that all the machinery of the X-15 would perform as designed under
flight conditions.
On this climactic day, when they placed their mechanical stethoscopes
to “listen” for signs of trouble in the X-15, the ground crews
were more meticulous than ever before. They checked every system
three times over, and then once again. Although I knew we couldn’t
possibly take off before 0900, I climbed into the X-15 cockpit,
fully rigged in the pressure suit, about 0700. I did this mainly for
morale-building purposes. I wanted the ground crews to know that I
had confidence in the airplane and that I was ready--eager--to get
into the air. It was an uncomfortably long wait, yet a necessary one,
I believed.
It was 0922 by the time Bock and Allavie lifted the B-52 off the
runway. We were late but the X-15 was tuned to a fine pitch. A few
minor items cropped up, as usual--a screeching in my radio receiver,
an insufficient flow of nitrogen coolant in the lower half of the
pressure suit--but during the familiar launch rehearsal the X-15 ran
a jeweled watch. We circled Edwards for an hour and fifteen minutes,
starting and stopping the APUs with no difficulty. The APU bearings,
cooled by nitrogen gas, held to a normal temperature range: about 115
degrees Fahrenheit.
It was clear now that we were over the big hurdle. We would have
stayed aloft longer that day, but the supply of APU nitrogen gas
coolant, designed to last only for a normal X-15 flight of about
half an hour, was dwindling rapidly, and as I have said before we
preferred to land with APUs operating in case Bock had to cut me
loose in emergency.
During the gradual descent the APU bearing temperatures began to
climb. Number one reached 245 degrees; number two moved up to
200 degrees. I was not unduly concerned. The bearings, G.E. had
calculated, could reach 400 degrees without seizing. Certainly we
could keep below that figure. To decrease the drain on the single
nitrogen gas supply, I turned off the windshield defogging and
pressure-suit ventilation. But the diminishing supply of nitrogen gas
to the APUs was not sufficient. Number one crept up to 295 degrees. I
watched the gauge closely. If it got much hotter, I intended to shut
it down and make the descent on one APU.
At 15,000 feet number one APU had inched ahead to 350 degrees. Since
it was approaching a danger point, I reported the fact by radio to Q.
C. Harvey. After consulting his panel of X-15 experts, gathered near
his mike in the NASA tower, Q.C. responded:
“Scotty. Q.C. We suggest you shut down number one APU if the bearing
temperature reaches 395 degrees.”
“Okay, Q.C.,” I replied. “That’s what I was going to do. Number one
bearing temperature is now 376 degrees.”
My eyes were glued on the number one APU bearing gauge. It moved
steadily ahead: 376 ... 380 ... 390 ... 395. I reached for a switch
on the instrument panel and turned it, reporting by radio:
“Number one APU 395 degrees. Shut down.”
My eyes remained on the gauge. I expected it to “coast” still higher
for a moment or so and then drop off rapidly. The gauge swung to
400 ... 416 ... 430. Number two APU, which was then getting all the
nitrogen gas coolant, leveled out at about 200 degrees, as expected.
I snapped into my mike:
“Q.C., this damned number one is up to 450.”
“You can expect it to peak a little bit and then fall off, Scotty,”
Q.C. replied.
“Yeah,” I said. “I know. But it isn’t falling off. It’s now up to 460
and climbing. Number two is okay, steady at 200 degrees.”
When the temperature of number one APU reached 475 degrees, I heard
a familiar rumbling in the rear of the X-15. The unit had seized and
vibrated to a stop. But why? Then in a flash I realized I had made a
dreadful error. I had not shut down number one APU at all. Instead, I
had shut down number two.
“Holy smoke,” I muttered on the radio circuit.
My spontaneous comment touched off a tremendous flurry of excitement
on the ground. Sam Richter came on the radio instantly.
“Scotty. Did you say smoke? Repeat. Do you have smoke in the
cockpit?” (I later learned that Charlie Feltz, who was in Sam’s van,
and whose ear was not then attuned to airplane radio circuits, leaped
from his chair and said: “Wha’d he say? Wha’d he say?” And thereafter
“Wha’d he say?” became a very big joke on the X-15 team.)
“No. No. Sorry,” I replied. “No smoke in the cockpit. I just goofed.
I shut down number two APU by mistake. Number one was running all the
time. It blew.”
It took only the thinnest imagination to conjure up the disbelieving
expressions which spread over the faces of the people on the ground.
After six agonizing months of APU difficulties, we had finally
made a successful airborne demonstration. Then at its climax I had
stupidly blown an APU because I turned the wrong switch. Short of
losing the airplane altogether, no mistake I might have made in the
air that day could have stung our team deeper. They could not have
been more depressed. I felt like a fool, and of course I assumed full
responsibility for the blooper.
The APU failure was properly judged pilot error. Since everything,
including APUs, was considered satisfactory, all hands agreed the
ship was fit for her next great test, the first glide flight to earth.