"It is a sap"s game," I agreed with him. "But starvation is dangerous too." He laughed, and we all laughed.
He studied me for a minute. We hadn"t seen each other in a couple of years. Finally he said soberly, "You"ve grown older, Jim."
"Yeah, I"ve grown older, Bill," I answered him banteringly, "and I want to grow a lot older too. I want to have a nice long white beard trailing out in the slip stream some day. So I hope you guys are building good airplanes for diving. By the way, let"s go out in the hangar and take a look at the crate. After all, I"m mildly interested in it, you know."
We all went out into the hangar. There was the ship, suspended from a chain hoist with its wheels just off the cement in the middle of a large cleared area. It was silver and gleamed even in the somewhat darkened interior. It looked st.u.r.dy and squat and bulldoggish, as only a military fighting ship can. I was glad it looked st.u.r.dy.
A group of mechanics were swarming around it and over it and under it.
They all looked up as we approached the ship. I knew most of them. I was introduced to the others. You could see that they felt toward that ship as a brood hen feels toward her eggs. They didn"t want me to break it. I didn"t want to break it either.
I walked around the ship and looked it over. The engineers pointed out special features and talked metal construction and forged fittings and stress a.n.a.lysis and safety factors, and I asked questions. I was fascinated by the wires that braced the wings. They looked big enough to hold up the Brooklyn Bridge. I liked those wires.
I learned that a pilot had been up there and had gone over the whole stress a.n.a.lysis with them and had recommended only one little change in the ship, which had been made. I learned that he had expressed willingness to dive the ship after that, but that he had been unable to because another job he had contracted to do some time previously was coming up at the same time this one was. I was glad to hear this man had gone over the ship. He was not only one of the most, if not the most, competent test pilots in the country, but also a very good engineer, which I was not.
I crawled into the c.o.c.kpit. There were more gadgets in it. Something for everything except putting wings back on in the air. The racket had changed, I decided. In the old days, dive demonstrating hadn"t been so accurate a thing. You took a ship up and did a good dive with it and came down and everybody was happy. But now, as I could see, they had developed a lot of recording as well as indicating instruments. You used to be able to get away with something. You couldn"t get away with anything now. They could take a look at all those trick instruments after you had come down and tell just what you had done. They could tell accurately and didn"t have to take your word for it.
There was one instrument there, for instance, that the pilot couldn"t see. It was called a vee-gee recorder. It made a pattern on a smoked gla.s.s of about the size of one of those paper packets of matches. This pattern told them, after the pilot had come down, just how fast he had dived, what kind of a dive he had made, and what kind of a pull-out he had done.
There was another instrument there that I had never seen before. It looked something like a speedometer and was called an accelerometer. I was soon to find out what that was for! Oh, they told me what it was for then. They explained everything in the c.o.c.kpit to me, and I sat there and familiarized myself with it as best I could on the ground before taking the ship out. But I wasn"t really to find out what that accelerometer was for until I used it. And did I find out then!
We rolled the ship out that afternoon, after last-minute adjustments had been made on it-an airplane is like a woman that way: it always has to have last-minute adjustments-and I made a familiarization flight in it.
I just took it off and flew it around at first. Then I began feeling it out. I rocked it and horsed it and yanked it and pulled it and watched.
I watched the wires, the wings, the tail. Any unusual flexing? Abnormal vibration? Any flutter? I brought the ship down and had it inspected that night.
The next day I did the same thing. But I went a little bit further this time. I built up some speed. I did shallow dives. I listened and felt and watched. I did steeper dives. Anything unusual?
This went on for several days. Some minor changes and adjustments were made. Finally I said I was ready to start the official demonstrations, and the official naval observers were called out to watch.
I did five speed dives first. These were to demonstrate that the ship would dive to terminal velocity. Contrary to popular opinion, a falling object will not go faster and faster and faster and faster. It will go faster and faster only up to a certain point. That point is reached when the object creates by its own pa.s.sage through the air enough air resistance to that pa.s.sage to equal in pounds the weight of the object.
When that point is reached, the object will not fall any faster, no matter how much longer it falls. It is said to be at terminal velocity.
A diving airplane is only a falling object, but it is a highly streamlined one, and therefore capable of a very high terminal velocity.
A man falling through the air cannot attain a speed greater than about a hundred and twenty miles an hour. But the terminal velocity of an airplane is a lot more than that.
I led up to it carefully. I went to fifteen thousand feet to start the first dive. The ship dove smooth and steady. I pulled out at three hundred miles an hour and climbed back up to do the next dive. I dove to three hundred and twenty miles an hour this time. Everything was fine.
Everything was fine as far as I could tell, but when I had eased out of the dive I brought the ship down for inspection before I did the next two dives.
I did the next two dives to three hundred and forty miles an hour and three hundred and sixty. I lost seven thousand feet in the last one. It had me casting the old fish eye around to see if everything was holding before I got through it. Everything held, but I brought the ship down for inspection again before the final speed dive.
I went to eighteen thousand feet for the final one. It was cold up there, and the sky was very blue. I lined all up facing down wind and found myself checking everything very methodically. Was I in high pitch?
Was the mixture rich? Was the landing gear folded tightly? Was the stabilizer rolled? Was the rudder tab adjusted? I was a little extra methodical and extra deliberate. I knew that my mind wasn"t normally clear. I was breathing harder than usual. It was the alt.i.tude. There wasn"t enough oxygen. I was a little groggy.
I was a little worried about my ears. I had always had to blow my ears out when just normally losing alt.i.tude. I had funny ears like that that wouldn"t adjust themselves. I might break an eardrum.
I eased the throttle back, rolled the ship over in a half roll, and stuck her down. I felt the dead, still drop of the first part of the dive. I saw the air-speed needle race around its dial, heard the roaring of the motor mounting and the whistle of the wires rising, and felt the increasing stress and stiffness of the gathering speed. I saw the altimeter winding up-winding down, rather! Down to twelve thousand feet now. Eleven and a half. Eleven. I saw the air-speed needle slowing down its racing on its second lap around the dial. I heard the roaring motor whining now, and the whistling wires screaming, and felt the awful racking of the terrific speed. I glanced at the air-speed needle. It was barely creeping around the dial. It was almost once and a half around and was just pa.s.sing the three-eighty mark. I glanced at the altimeter.
It was really winding up now! The sensitive needle was going around and around. The other needle read ten thousand, nine and a half, nine. I looked at the air-speed needle. It was standing still. It read three ninety-five. You could feel it was terminal velocity. You could feel the lack of acceleration. You could hear it too. You could hear the motor at a peak whine, holding it. You could hear the wires at a peak scream, holding it. I checked the altimeter. Eight and a half. At eight I would pull out.
Suddenly something shifted on the instrument board and something hit me in the face. I sickeningly remembered that dazing smack on the head of six years before, and the old electric startle shock convulsed me as I remembered the resounding crack of those wings tearing off. I involuntarily took a fear-glazed glance at my wings and instinctively tightened up on the stick and began to ease out of the dive. Through the half-daze pull-out and the dawning ice-cold clearness always aftermathing fright I dimly checked the trouble while I leveled out.
When I had got level and got things quieted down and my head had cleared I saw that I was right. Only the gla.s.s cover had vibrated off the manifold-pressure instrument, and the needle had popped off the dial. I was thoroughly shaken. And I was mad because I had allowed so little a thing to upset me so much.
I checked my altimeter. It read five thousand feet. I figured I had dived eleven thousand and taken two for recovery.
My ears had a lot of pressure on them. I held both nostrils and blew.
The pressure inside popped my ears out easily. They were going to stand the diving all right.
I brought the ship down to be inspected that night and decided to celebrate the successful conclusion of the long dive. Cirrus clouds were forming high up in the blue sky, so I figured maybe I could do it safely. I went up to the weather bureau on the field to check on it.
"How is the weather for tomorrow?" I asked. "Terrible, I hope."
"I think it will be," the weather man said. He consulted his charts further. "Yes, it will be," he a.s.sured me.
"Definitely?" I pressed him.
He looked his charts over again. "Yes," he rea.s.sured me, "definitely.
You won"t be able to fly tomorrow."
"Swell!" I exclaimed to the mildly startled man. He didn"t quite get it.
It was lousy the next morning, all right. You couldn"t see across the field. Even the birds were walking. The engineers were dismayed. They wanted to get on with the demonstrations. I was overjoyed. I had a head.
I had celebrated a little too much.
Along about the middle of the morning it began to lift. The engineers began to cheer up. I watched with gathering apprehension while it lifted still further and began to break. In an incredibly short time there were only a few clouds in the sky. I was practically sick about it, but the engineers, with beaming faces, were having the ship pushed out.
I went up to the field lunch wagon to get a cup of coffee while the mechanics warmed up the ship.
I went back down to the hangar and crawled into the ship to do the first two of the next set of five dives. These were to demonstrate pull-outs instead of speed. Here was where I found out what the accelerometer was for.
I knew that the accelerometer was to indicate the force of the pull-outs. I knew that it indicated them in terms of _g_, or gravity. I knew that in level flight it registered one _g_, which meant, among other things, that I was being pulled into my seat with a force equal to my own weight, or one hundred and fifty pounds. I knew that when I pulled out of a dive, the centrifugal force of the pull-out would push the _g_ reading up in exactly the same proportion that it would pull me down into my seat. I knew that I had to pull out of a ten-thousand-foot dive hard enough to push the _g_ reading up to nine, and pull me down into my seat with a force equal to nine times my own weight, or thirteen hundred and fifty pounds. I knew that that would put a considerable stress on the airplane, and that that was the reason the Navy wanted me to do it; they wanted to see if it could take it. But what I didn"t know was that it would put such a terrific stress on me. I had no idea what a nine _g_ pull-out meant to the pilot.
I decided to start the dives out at three hundred miles an hour and increase each succeeding dive in increments of twenty miles an hour for the first four dives, as I had in the speed dives. I decided to pull out of the first dive to five and a half _g_, and pull out of each succeedingly faster dive one _g_ harder, until I had pulled out of the fourth dive of three hundred and sixty miles an hour to eight and a half _g_. Then I would do the grand dive of ten thousand feet to terminal velocity and pull out to nine _g_.
I took off and went up to fifteen thousand feet and stuck her down to three hundred miles an hour. I horsed back on the stick and watched the accelerometer. Up she went, and down into my seat I went. Centrifugal force, like some huge invisible monster, pushed my head down into my shoulders and squashed me into that seat so that my backbone bent and I groaned with the force of it. It drained the blood from my head and started to blind me. I watched the accelerometer through a deepening haze. I dimly saw it reach five and a half. I eased up on the stick, and the last thing I saw was the needle starting back to one. I was blind as a bat. I was dizzy as a coot. I looked out at my wings on both sides. I couldn"t see them. I couldn"t see anything. I watched where the ground ought to be. Pretty soon it began to show up like something looming out of a morning mist. My sight was returning, due to the eased pressure from letting up on the stick. Soon I could see clearly again. I was level, and probably had been for some time. But my head was hot with a queer sort of burning sensation, and my heart was pounding like a water ram.
"How am I going to do a nine-_g_ pull-out if I am pa.s.sing out on five and a half?" I thought. I decided that I had held it too long and that I would get the next reading quicker and release it sooner, so I wouldn"t be under the pressure so long.
I noticed that my head was completely cleared from the night before. I didn"t know whether it was the alt.i.tude or the pull-out. One or the other, or both, I decided, was good for hang-overs.
I climbed back to fifteen thousand feet and stuck her down to three hundred and twenty miles an hour. I horsed back quick on the stick this time. I overshot six and a half and hit seven before I released it. I could feel my guts being sucked down as I fought for sight and consciousness, but the quicker pull and the earlier release worked, and I was able to read the instruments at the higher _g_.
I brought the ship down for inspection. Everything was all right. I went back up again and did the next two. They sure did flatten me out, but the ship took it fine. I brought it down for a thorough inspection that night.
I felt like I had been beaten. My eyes felt like somebody had taken them out and played with them and put them back in again. I was droopy tired and had sharp shooting pains in my chest. My back ached, and that night I blew my nose and it bled. I was a little worried about that nine-_g_ business.
The next morning was one of those crisp, golden autumn days. The sky was as blue as indigo and as clear as a mountain stream. One of those good days to be alive.
To my surprise, I felt fine. "Those pull-outs must be a tonic," I thought.
I went out to do the terminal-velocity dive with the nine-_g_ pull-out.
I found that the last dive I had done the day before had flattened out the fairing on the belly of the ship. The sudden change of att.i.tude of the ship in the eight-and-a-half _g_ pull-out had pushed the belly up against that pretty solid three-hundred-and-sixty-mile-an-hour blast of air and crushed the metal bracings that held the belly fairing in shape as neatly as if you had gone over it with a steam roller. It was not a structural part of the ship, however, as far as strength went, and could be repaired that day. They decided to beef up the bracings when they repaired it.