Chapter 35: ►

_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.