A toy similar to this one http://www.dhgate.com/product/novelty-toys-ufo-with-light-remote-control/135334429.html weighs 30 grammes on a digital scale. It hovers and flies. Holding the toy over the weighing scale with the motor turned on, with sufficient thrust to fly, I was astonished to see the force of the air on the weighing scale register 35 - 40 grammes! Thrust greater than weight? What is hapenning here?