Free One Summer: America, 1927 by Bill Bryson

they were reliable enough. He would compute his fuel use manually, though that was essentially an academic exercise: either he would have enough fuel or he wouldn’t. The plane also had no brakes. Planes in 1927 almost never did. That would not matter in most circumstances, but it would prove an unnerving absence when, later, crowds streamed on to runways wherever Lindbergh landed.
    The plane’s frame was covered in Pima cotton painted over with six coats of aluminium-pigmented dope – a kind of aromatic varnish that made the cotton shrink to fit tight around its wood and tubular-steel skeleton. Although the Spirit of St Louis looked metallic, and was often described as such in newspaper reports, only the nose cowling was actually of metal. With only a thin layer of canvas between Lindbergh and the outside world, the Spirit of St Louis was deafeningly noisy and unnervingly insubstantial. It would have been rather like crossing the ocean in a tent. Lindbergh and the other Atlantic competitors were slightly too early for a great unsung invention of the age – Alclad, a new type of non-corrosive aluminium invented by Alcoa and unveiled later that year. For the next eighty years (until the introduction of carbon fibres) virtually every plane built on earth would have an Alclad skin – but not in the summer of 1927. Lindbergh did at least have a metal propeller, which was much more reliable and resistant to cracking than the wooden propellers used until quite recently. The American flyers also had an advantage over their European competitors that nobody yet understood. They all used aviation fuel from California, which burned more cleanly and gave better mileage. No one knew what made it superior because no one yet understood octane ratings –that would not come until the 1930s – but it was what got most American planes across the ocean while others were lost at sea.
    The completed Spirit of St Louis , as has often been said, was little more more than a flying fuel tank. Though it was vastly sleeker than planes of a few years earlier, it still had a lot of drag built into it: the jutting cylinders on its engine, its many struts and guy wires, above all its fixed landing gear with its two dangling wheels dragging through the wind – all acted like an arm thrust out of a car window. To maximize mileage, every ounce of unnecessary weight was discarded. Lindbergh took nothing he didn’t need. He reportedly even trimmed the white margins off his maps.
    Because of its many design compromises, the plane was not nearly as stable as it ought to have been – a fact that troubled Hall greatly – but there wasn’t time to make it better and Lindbergh was convinced, probably rightly, that having to work harder would help him to stay awake. ‘Lindbergh didn’t want an innovative plane,’ says Alex Spencer of the Smithsonian National Air and Space Museum in Washington. ‘He wanted nothing but tried and tested technology.’
    Only the engine, a 223-horsepower Wright J-5 Whirlwind, was of a new design. It was the one thing on the plane that was unquestionably of the latest technology. The J-5 was air-cooled, which made it simpler, lighter and more reliable than conventional water-cooled engines, and it had two additional benefits. It was the first machine in the world to incorporate Samuel Heron’s sodium-cooled valves, which eliminated the serious problem of burned exhaust valves, and it had self-lubricating rocker arms, which allowed the valves to putter along contentedly for hours without attention. The J-5 was first used on Richard Byrd’s North Pole flight in 1926, and did its job admirably. The irony, as we shall see, is that Byrd probably never got anywhere near the North Pole.
    Lindbergh made his first test flight on 28 April, two months to the day after placing the order. The plane performed better than he had dared to hope. It was agile and fast – he got it up to 128 miles an hour on its first flight – and it