Abstract: Unmanned aerial vehicles (1), and methods of flying such, comprising at least four rotors (2) arranged such that the plane of rotation of each rotor (2) is co-planar with a face of a notional polyhedron, and wherein each face of the notional polyhedron is co-planar with the plane of rotation of at least one rotor (2). Such methods comprise: a first step of flying the vehicle (1) using a first rotor set (2a-c) to provide lift; and, a second step using a second rotor set (2d-f) to provide lift; wherein, the second rotor set (2d-f) includes at least one rotor (2) that is not used to provide lift in the first step or that operates so that airflow through the rotor (2) is in the opposite direction to that through the rotor (2) during the first step; and, wherein at least one of the first and second sets (2a-c, 2d-f) comprises a plurality of rotors (2).