GB732966A - Improvements in or relating to a blade for rotary wing aircraft - Google Patents

Abstract

732,966. Blades for rotary wing aircraft. UNITED AIRCRAFT CORPORATION. Sept. 6, 1951 [Sept. 21, 1950], No. 21063/51. Class 4. A rotor blade for a rotary wing aircraft, comprising a tubular spar member which forms the leading edge and strength member of the blade and conforms to the aerofoil contour of the blade throughout a substantial chordwise extent from the leading edge aft, said member having its chordwise centre of gravity located substantially at the aerodynamic centre of the blade, a plurality of non-structural fairing members being carried by the trailing edge of said tubular spar member and completing the aerofoil contour of the blade, is characterized by a plurality of non-structural weights located in the outboard portion of said tubular spar member forward of the chordwise centre of gravity thereof for balancing said trailing members about the chordwise centre of gravity of the blade. The blade comprises a hollow extruded leading edge section 10 secured at its root end to an attachment fitting 48 and having its trailing edge profile completed by a plurality of panels 13 and an outer panel 12 that extends over approximately half the span. The section 10 is formed interiorly with a plurality of spanwise ribs or projections 30, the two forward ones being arranged to retain a plurality of balance weights 56 along the outboard portion of the leading edge. A plate channel member may be fitted within the section 10 to form, with the leading edge portion of the section, a thermal de-icing duct supplied with fluid by a conduit 33 and arranged to exhaust through an outlet pipe 36, 38 located in the tip 34. Specification 586,443 is referred to. Reference has been directed by the Comptroller to Specification 586,443.