How is it that two bicycle-shop owners from Dayton, Ohio, managed to do what many others before them had tried but failed to do — invent the airplane? In this interview from NOVA Online, Wright biographer and aeronautics historian Tom Crouch explains how a genius for engineering, a dogged perseverance, and an unflagging belief in the ultimate success of their enterprise paid off for the Wright brothers on December 17, 1903, the day they ushered in the airplane age.