Abstract: The invention arose in the design of vertical takeoff craft where a bladed rotor directs a jet of fluid over a curved surface so that the jet is turned from a radial direction towards an axial direction to create lift. These craft have stability problems when an attempt is made to hover close to the ground or to a vertical surface and for this reason such craft have been confined to paper proposals and unsuccessful experimental models. In accordance with the invention, the craft is designed so that its rotor and other moving parts have a large angular momentum. In this way, a gyroscopic effect is achieved, sufficient to give positive stability to the craft, eliminating the aforementioned problem.