Actuating system for wing leading-edge slats

A wing leading-edge slat actuating system comprising a beam fast with the wing, an intermediate slat having a trailing edge and hinged to said beam, a front slat hinged to said beam, and a leading edge hinged to said front slat, characterized in that said system includes a first jack having one end hingedly connected to a fixed point on the wing and a second end hingedly connected to a moving point fast with said front slat and placed substantially at middle distance on a line drawn from a hinge point common to said front slat and said leading edge and reaching a trailing edge of said front slat;

• two rectilinear rods on either side of said jack having their hinge-points respectively located, on the one hand, at points fast with said leading edge which is fair shaped and on an outer part of the undersurface thereof, and at fixed points on said beam on the other;
• a second jack having a fixed hinge-point on the wing and a moving hinge-point on said intermediate-slat trailing edge;
• said jacks and rods being so arranged that when said jacks are in their extended position said slats are extended and form two slits, one of said slits between said intermediate slat and said wing and the other slit between said front slat and said intermediate slat, it being possible for said slits to be masked for certain flight configurations such that when said jacks are in their retracted position said slats have been retracted by pivotal motion and blend completely with the leading-edge profile.