HELICOPTER MAIN ROTOR BLADE Russian patent published in 2008 - IPC B64C27/46 

FIELD: aviation.

SUBSTANCE: proposed blade has shank section and aerodynamically profiled section; it also has chord, rounding-off radii of nose section of profile and tail plate. Aerodynamic profiles of sections which are normal relative to blade longitudinal axis have thickness ratio of 0.109-0.121 of profile chord within range of relative radii of from 0.5-0.6 to 1.0. Coordinates of maximum thickness ratio are within 0.32-0.46 of profile chord. Radius of tangent of circle of profile leading -edge which is common for upper and lower parts of profile contour is equal to 0.012-0.026 of profile chord. Maximum curvature of profile medium line is equal to 0.02-0.025 of chord and is located within 0.20-0.40 of chord. On trailing edge, angle between tangent to medium line and chord is not positive, it is equal to 0-2 degrees. Geometric twist of shank section is equal to zero. Finned part of blade begins from relative radii of 0.20-0.35. Width of tail plate is equal to 0.04-0.14 of profile chord without plate.

EFFECT: improved quality of blade.

7 dwg, 1 tbl