One embodiment of a Vertical Take-off and Landing (VToL) air-vehicle (FIG. 1.) having a horizontal rotor, a. providing lift and propulsion, and communicating at or near its centre to structural elements, or fuselage, b. Upon or within the fuselage structure is attached a platform, to which a payload, or occupant or pilot, d. is secured in such a manner as to permit a movement, or range-of-motion, of the payload, as a means of weight-shifting, or mass-balancing, of the vehicle for stability and control in flight. At least two planar elements, or descent-vanes, c.i & c.ii are connected to a structural element of the fuselage at a location which provides vertical and horizontal separation between the rotor and the descent-vanes, thus creating a tandem, biplane arrangement of two aerodynamically active elements which are aerodynamically balanced to provide stability and controllability in hovering flight, in forward flight, and in un-powered gliding and vertical descents. Other embodiments are described and shown.