For one fleeting moment, the Hélica—a plane without wings and an “unsteerable murder machine”—looked like the future of transportation. Good thing it wasn’t. ______________________________________________________________________________________ In 1909, Marcel Leyat, an engineer from the tiny mountain town of Die in southeastern France, designed and built his first airplane. Not long after, he ran out of money. The young engineer had trained in aeronautics, only to find his skillset obsolete in a market controlled by the military; bespoke airplanes were a dying business. Undaunted, Leyat turned his attention to the pursuit of his real dream: building what he called a “plane without wings.”...