A hybrid lift air vehicle for lifting and transporting a payload to a delivery location, which comprises a helium or other lighter-than-air gas filled envelope mounted on an airframe. A first insulating layer is disposed on sidewalls of the via. A viewer-tracking system monitors the viewer’s movements and directs each image of a stereopair to the proper eye of the viewer. The driving sprocket is disposed in a plane including the driven sprocket, and powers a chain.