What the Dog Saw [112]
Had Kennedy been flying during the day or with a clear moon, he would have been fine. If you are the pilot, looking straight ahead from the cockpit, the angle of your wings will be obvious from the straight line of the horizon in front of you. But when it’s dark outside, the horizon disappears. There is no external measure of the plane’s bank. On the ground, we know whether we are level even when it’s dark, because of the motion-sensing mechanisms in the inner ear. In a spiral dive, though, the effect of the plane’s G-force on the inner ear means that the pilot feels perfectly level even if his plane is not. Similarly, when you are in a jetliner that is banking at thirty degrees after takeoff, the book on your neighbor’s lap does not slide into your lap, nor will a pen on the floor roll toward the “down” side of the plane. The physics of flying is such that an airplane in the midst of a turn always feels perfectly level to someone inside the cabin.
This is a difficult notion, and to understand it I went flying with William Langewiesche, the author of a superb book on flying, Inside the Sky. We met at San Jose Airport, in the jet center where the Silicon Valley billionaires keep their private planes. Langewiesche is a rugged man in his forties, deeply tanned, and handsome in the way that pilots (at least since the movie The Right Stuff) are supposed to be. We took off at dusk, heading out toward Monterey Bay, until we had left the lights of the coast behind and night had erased the horizon. Langewiesche let the plane bank gently to the left. He took his hands off the stick. The sky told me nothing now, so I concentrated on the instruments. The nose of the plane was dropping. The gyroscope told me that we were banking, first fifteen, then thirty, then forty-five degrees. “We’re in a spiral dive,” Langewiesche said calmly. Our airspeed was steadily accelerating, from 180 to 190 to 200 knots. The needle on the altimeter was moving down. The plane was dropping like a stone, at three thousand feet per minute. I could hear, faintly, a slight increase in the hum of the engine, and the wind noise as we picked up speed. But if Langewiesche and I had been talking, I would have caught none of that. Had the cabin been unpressurized, my ears might have popped, particularly as we went into the steep part of the dive. But beyond that? Nothing at all. In a spiral dive, the G-load — the force of inertia — is normal. As Langewiesche puts it, the plane likes to spiral-dive. The total time elapsed since we started diving was no more than six or seven seconds. Suddenly, Langewiesche straightened the wings and pulled back on the stick to get the nose of the plane up, breaking out of the dive. Only now did I feel the full force of the G-load, pushing me back in my seat. “You feel no G-load in a bank,” Langewiesche said. “There’s nothing more confusing for the uninitiated.”
I asked Langewiesche how much longer we could have fallen. “Within five seconds, we would have exceeded the limits of the airplane,” he replied, by which he meant that the force of trying to pull out of the dive would have broken the plane into pieces. I looked away from the instruments and asked Langewiesche to spiral-dive again, this time without telling me. I sat and waited. I was about to tell Langewiesche that he could start diving anytime, when, suddenly, I was thrown back in my chair. “We just lost a thousand feet,” he said.
This inability to sense, experientially, what your plane is doing is what makes night flying so stressful. And this was the stress that Kennedy must have felt when he turned out across the water at Westerly, leaving the guiding lights of the Connecticut coastline behind him. A pilot