He looked his charts over again. “Yes,” he reassured 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 passing 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.