As one means of achieving the required movement of a flying control the simple skew-hinge mechanism appears attractive because it has a significant range of approximately linear operation and because all of its mechanical components can be accommodated easily within the sort of shallow depth available in some wings. The mechanism is kinematically similar to that of the well-known Z-crank and Fig. 1 shows one possible arrangement of it inside a wing. For this particular case an axial translation of the control push-pull rod AA causes rotation of the flying control H about its hinge axis BB and the mechanical connection between these driving and driven members consists of the skew-hinge itself, which is attached to the flying control H and which has an axis CC which intersects the axis BB at an angle α, together with the other components of the mechanism. These are the hinge driving-block F, the driving-link G, and the drive transmission-collar I.