GB998895A - Improvements relating to aircraft - Google Patents

Abstract

998,895. Boundary layer control. DE HAVILLAND AIRCRAFT CO. Ltd. July 20, 1961 [Aug. 4, 1960], No. 27001/61. Heading F2R. [Also in Division B7] A droop nose aircraft wing has a closure member to fill a` spaee formed between the drooped portion and the main wing section, movable from an operative position, in the drooped position of the nose section, in which the outer wall of the closure member forms a continuation of the upper surfaces of the nose and main wing sections, to a retracted flight position which the nose section returns to its normal flight position, the outer wall being formed at least in part by a permeable element spaced from an inner wall to form a chamber therebetween, means being connectible to the chamber to produce a pressure differential across the permeable element. The wing 12 comprises a main section 14 and a droop-nose section 20 mounted on a hinge 32 for pivotal movement under the control of an hydraulic jack 30. The section 20 carries a curved panel 42 which, during movement of the section, co-operates with a pivoted closure member 38, mounted on a hinge 36 and inter-connected with section 20 by a link 66 so that when section is drooped as shown, the member 38 fills the space between the upper surfaces of sections 14 and 20. The member 38 comprises an outer perforated plate 40 and an inner plate 44 which forms a chamber 46 connected by a flexible conduit 50 to a transverse duct 52 in the wing. In operation, jack 30 is operated to droop section 20 and suction is applied to duct 52 to remove boundary layer air through plate 40. After restoration of the apparatus to normal flight position compressed air is supplied to duct 52 to clear obstructions in the perforations of plate 40. The hydraulic jack may be replaced by screw jacks.