Once again his quadcopter drone, a buzzing machine roughly the size of a loaf of bread, zooms daringly around obstacles and through hairpin turns; once again, it meets its demise. Welcome to drone racing, a would-be sport in which men, and a few women, fly remote-controlled drones against competitors at up to 80 miles per hour along looping courses with hairpin curves and drops. Fans sit on bleachers behind protective mesh, passing around antenna-equipped goggles to see the pilot's view. Big-screen TVs show off unique camera angles while glowing copters whizz by, emitting the high-pitched hum of weed whackers on steroids. While high-profile races such as the World Drone Prix, held in Dubai last March, pay out as much as $250,000 to the winning pilot, such affluence feels very distant here in the shell of the Hawthorne Plaza mall. The fast-talking 35-year-old helped turn "Tough Mudders," a quirky half marathon in which people pay to slog through artificial quagmires, into a $100-million-plus business as its chief revenue officer. Paintball thrived for several years, airing its own show on ESPN3 and drawing sponsors like Budweiser, Monster energy drinks and the U.S.