On the shore of Lake Isabella, about 150 miles north of Los Angeles, a crowd of flight techs, most of them either pierced or tattooed, swarms around a small white airplane. It's called an Icon A5. It's a collaboration between an F-16 pilot and a skateboard designer, and it looks like an odd, rakish sea monster.

Today is the plane's first flight. Aeronautical calculations, computer simulations, and wind tunnel tests have been performed, of course. And yet … every maiden flight is a dance with death. If all that math was foolproof, after all, no one would need test pilots. At 6:30 am, the winds are calm. Jon Karkow pulls a parachute over his shoulders, hugs his girlfriend—a long embrace with whispers exchanged—and clambers into the cockpit; the A5 is remarkably stable on the water for something with a knife-edged underside. The tech crew chief closes the cockpit and gives the carbon-fiber skin a few pats; Karkow fires up the propeller and taxis the A5 out onto the lake.