Paul MacCready with a van, son Tyler and pterosaur model. Lacking a wind-tunnel, the model is driven up and down a street in Simi Valley. MacCready's son Tyler (atop the van) and Aerovironment staff hang from the sides, observing while instrumentation measures the flight characteristics.Thewing-flapping 1/2 scale model mimics the 11 m wing-span 'Quetzalcoatlus northropi' (QN), largest animal to have flown on earth, extinct for 65 million years. QN, lacking a tail,had no inherent dynamic stab