Igor Sikorski's prototype machine, vertical jets and the revolutionary and controversial tilt-rotor designs of the 1990s are in the spotlight as Fly Past chronicles the development of vertical takeoff vehicles. The second episode, "Straight Up", details the history of VTOL (vertical takeoff and landing) aircraft, from Leonardo DaVinci's drawings, through Igor Sikorsky's invention of the helicopter, to the development of tilt-rotor and vectored-thrust machines such as the XV-15, V-22, Harrier, and the X-32/X-35 Joint Strike Fighter.