Turbulence Read Free Page A

each snowflake in my head: p = the pressure, h = the height, x = the mass of water per unit mass, v = the velocity per unit mass, y = the entropy …
    â€˜You want to avoid cumulonimbus,’ I said to the pilot, after a while watching the snow clouds. ‘Very bad for turbulence.’
    â€˜To the deuce with that,’ he said, pushing the joystick. We went into a sharp dive. The plane began to spin, a phenomenon at first oddly lacking in turbulence, since it was controlled. Nonetheless, it was terrifying.
    I knew that if there was a ‘wobble’ severe turbulence would soon occur and we could lose control of the plane. I had done experiments on this sort of thing while at Cambridge – throwing boomerangs on the Backs and seeing when they would lose aerodynamism, or spinning beach pebbles on wooden surfaces and judging when they would fall.
    We continued to drop. A penetrating noise sounded through the riveted aluminium of the cabin. ‘What the hell are you doing?’ I shouted.
    We were still heading down, diving through one cloud layer after another, the engine roaring – 6,000 feet, 5,000, 4,000 …
    â€˜Are you telling me how to fly?’ came the reply through the headphones. ‘I’ve been flying cunims since you were in short trousers. This is nothing! I’ve flown in weather in which even the birds were walking.’
    I clutched my seat, feeling the beans and bacon rise in my stomach. ‘That may be so,’ I said, ‘but …’ My voice dried up as wordless terror filled my bones.
    He stamped on the pedals and pulled out the throttle to full. The nose was still pointing down. I looked at the altimeter in horror. The engine screamed as aero-fuel shot into it – and then in another swift movement he centralised the joystick.
    Suddenly we were upright and calm. The needle began to creep round the dial – 2,000 … 3,000 … 4,000 … then he flattened out, allowing the instruments to acquire level values for a minute or two, before starting to climb again steadily.
    â€˜What did you do that for?’ I said angrily as we regained height. ‘Is that your idea of a joke?’ With the increase in height came a faint feeling of my intestines being squeezed.
    The pilot laughed. ‘Simmer down, old chap. I was doing a thumb.’
    â€˜A thumb?’ I asked, my heart still racing. Something familiar rubbed at the back of my mind. Not ‘thumb’ – THUM: Temperature and Humidity. The manoeuvre was a legitimate one to record those values at successive heights. But there was no need to do THUMs over the English Midlands.
    I spent most of the rest of the journey in sullen silence, staring into the oncoming snow. There was not much I could do. The joker was a Lieutenant Geoffrey Reynolds, who proceeded to tell me about a noteworthy engagement in which he had become involved. Flying back from his sortie he had spotted a U-boat on the surface. The U-boat crash-dived on seeing him but Reynolds attacked with two anti-submarine bombs that exploded just ahead of the wake …
    â€˜The U-boat was virtually blown out of the water, rearing up stern first before sinking. I was bloody chuffed with myself, I can tell you, and headquarters were pretty pleased, too.’
    I imagined the U-boat sinking in a widening slick of bubbles and oil and flotsam. ‘They wouldn’t have been quite so happy if the U-boat had had time to call in air support,’ continued Reynolds. ‘Mind you, nothing’s so hairy as picking up damaged instruments from weather ships. The crews sling them out in a waterproof bag on a line attached to a buoy, and we have to fly down and pick up the line with a hook lowered from the undercarriage. Then come round again and throw the new gauges down to the crew. You don’t want Jerry creeping up on you in the midst of that malarkey. It seems a lot of trouble to go to for a broken barometer. I don’t