GB741261A - Improvements in or relating to airfoils for airplanes - Google Patents

Abstract

741,261. Aircraft. LANIER, E. M. Nov. 3, 1953, No. 30381/53. Class 4. An aerofoil has a passage extending from the upper to the lower surfaces, defined by a fixed front wall 36 (Fig. 2) of successively concave and convex configuration, and a movable rear wall 37 of matching configuration terminating in a portion 41 adapted to close the passage, or to open it and to form a scoop to direct the airstream into the passage, the rear wall 37 being pivoted near the upper surface of the aerofoil and movable to vary the cross-section of the passage. The wall 37 is pivoted at 40 to a lug on a spanwise member 13, and is connected at 46 to a link 49 pivoted to a lever 48 secured to a rotatable member 26 also extending spanwise of the wing, and under the control of the pilot. If the wing is in two portions with relative dihedral, universal joints are disposed in member 26. Positions of the wall 37 and member 41 are shown in dashed and chain dotted lines, and the member 41 has a flexible rear portion 42 to permit the positions shown. A portion 28 of the upper wing surface may be flexibly connected at 58 to the skin, and be movable inwardly by rotation of a member 27 under the control of a pilot. The members 26 and 27 may be interconnected by gearing, and have a control device affording, for example, twelve possible positions. A plurality of passages may be provided in a wing, separated by chordwise ribs. Operation of member 28 while the passage remains closed increases the drag for braking purposes. The device may be operated in conjunction with the elevators when angles of attack near the stalling angle are approached. Fig. 14 is an embodiment in which a further passage 81 of fixed configuration is provided, also closable by the member 84 which closes the passage 82. In Fig. 15, the portion 28d extending between the two passages 81d and 82d is movable into the wing like the member 28 of Fig. 2. Alternatively two variable passages each with a scoop may be provided, one near the trailing edge and one near the leading edge. One or both may have an associated member 28. Blowers are used to provide air ejected from a pair of tubes, one above and one below the wing, a pair being provided at the tip of each wing blowing from the leading edge rearwardly to control the boundary layer.