AirVenture Oshkosh is the largest air show on the planet, with more than 10,000 aircraft and more than half a million people. Viewers get an insider's perspective when National Geographic flies along with the world's best aerobatic pilots as they twist and tumble through the sky, and follow a father and son crew as they fly their restored P-51 Mustang on its maiden voyage to Oshkosh after a 14-year restoration—and compete for best in show. But even with unparalleled preparation and precaution two things could destroy this event—bad weather and bad luck.