On the Wing Read Online Free PDF Page B

out, the name of the vehicle itself, an air(borne) plane. So, which is it: the lowered pressure on the upside of an airfoil or the greater pressure on the underside of a plane at the proper angle of attack? (In certain circles, this is still the subject of lively debate.) For the answer, I turn to Pope and Otis, my quondam mentors Frank and Art:
    When an airfoil is presented to the wind at a positive angle of attack, the impact of the air on the under surface of the airfoil produces lift. This kind of lift is called dynamic lift. [The] lift which comes from the reduced pressure of the air above an airfoil is called induced lift. The total lift is the sum of these values, which is merely the difference between the increased pressure below and the diminished pressure above the airfoil.

    F RANCIS P OPE AND A RTHUR S. O TIS , E LEMENTS OF A ERONAUTICS
    For Frank and Art, it’s not a case of either-or. Both the dynamic and induced forms of lift play their parts.
    As it is in flight, so it is in life—my life with Albertine, at any rate.
    When Albertine commences an undertaking, she assumes a positive angle of attack and thrusts herself forward, attacking that undertaking head-on, with power and purpose and a plan. The undertaking could be something as simple as a cross-country drive or as complex as “taking Peter out for an airing so that his outlook on life will be refreshed.” The result is the same: the woman produces lift. Her kind of lift is called dynamic lift.
    When I commence an undertaking, I begin conducting thought experiments at once, and in a remarkably short time my head is in the clouds. My kind of lift is called induced lift.
    Through the combined effects of dynamic and induced lift, Albertine and I manage to transport each other over many of life’s little obstacles. Ordinarily, she provides the dynamic lift, and I’m the simple airfoil, providing the induced lift. Together, we are a complex airfoil like the one described by Frank and Art.
    So it has been for many years, but something happened to Albertine during her recovery from her crash and fracture. She underwent a Baudelairean turn toward childhood, and to my great surprise began to exhibit an inclination and talent for producing induced lift, culminating in her selection of the Electro-Flyer as a vehicle suitable for a cross-country trip. I found this a little alarming. What would such a trip be like with two agents of induced lift and none of dynamic lift? I was relieved to find, while we were packing the Electro-Flyer, that she had reverted to form.
    â€œYou know,” I said, squeezing a small bag into a small nook in a corner of the trunk, “in recent years, my favorite journeys, my best journeys, have been the ones I’ve made in my mind. They have required no shopping, no tickets, no luggage, no packing, and no maps.”
    â€œMmm,” she said, thereby displaying her practical dynamic-lift side by disparaging my impractical induced-lift side.
    â€œArmchair travel is surely one of the greatest benefits of the human imagination,” I asserted.
    â€œOne of its virtues,” she admitted, “is that you get to sleep in your own bed.” She frowned at the pile of things we hadn’t been able to find nooks for. “I’m beginning to think that we should have bought a car with a bigger trunk.”
    â€œThe tiny trunk makes it more like my aerocycle—which hardly had room for a change of socks.”
    â€œOh, I do hope we’re not going to find it difficult to get our laundry done,” she fretted. “We have only a week’s worth of underwear each.”
    â€œWe could stuff some more into the pockets in the doors if we got rid of all those maps and turn-by-turn directions and just trusted to hunch, whim, and serendipity.”
    â€œIf you’re going to travel with me, Peter, you’re going to be in a car driven by a woman who knows where she’s