The Flight Demonstration Wind Tunnel (AF4IV) from TecQuipment is an open-circuit wind tunnel with a suspended model aircraft designed for classroom demonstrations and learner investigations of the behavior of fixed-wing aircraft and wing performance during take-off and landing. With its open-circuit wind tunnel, learners can study the effect of speed on attitude, measure the lift curve for the wing up to and beyond stall, plot trim curves, and determine the neutral point and more.