Patent ID: 6315522
Filing Date: 2001-11-13
Classification: B64C,Y10S

Abstract:
A helicopter blade aerofoil having coordinate values within .+-.3% errors of upper and lower surfaces on the basis of a reference aerofoil having a thickness to chord ratio of 10%, of which upper and lower surfaces are substantially defined by the following coordinates, and of which leading edge profile is substantially defined by the following leading edge radius and center of a circle:X/C Yup/C Ylow/C 0.00000 0.00000 -0.00000 0.00100 0.00511 -0.00584 0.00250 0.00843 -0.00813 0.00500 0.01218 -0.01014 0.00750 0.01505 -0.01136 0.01000 0.01747 -0.01218 0.01250 0.01959 -0.01277 0.01500 0.02150 -0.01328 0.01750 0.02325 -0.01375 0.02000 0.02487 -0.01415 0.02500 0.02780 -0.01483 0.05000 0.03891 -0.01714 0.07500 0.04682 -0.01862 0.10000 0.05291 -0.01979 0.15000 0.06152 -0.02206 0.20000 0.06666 -0.02470 0.25000 0.06892 -0.02729 0.30000 0.06895 -0.02949 0.35000 0.06841 -0.03109 0.40000 0.06744 -0.03211 0.45000 0.06568 -0.03270 0.50000 0.06301 -0.03272 0.55000 0.05943 -0.03211 0.60000 0.05498 -0.03084 0.65000 0.04968 -0.02883 0.70000 0.04349 -0.02600 0.75000 0.03649 -0.02237 0.80000 0.02886 -0.01794 0.85000 0.02087 -0.01315 0.90000 0.01279 -0.00777 0.95000 0.00538 -0.00304 1.00000 0.00236 -0.00095Leading edge radius r/C=0.0096,Center of circle X/C=0.0097, Y/C=-0.0018,where X is a distance from the leading edge to a trailing edge along a chord line of the aerofoil, C is a length of the aerofoil in the chord direction, Yup is a distance from the chord line to the upper surface, Ylow is a distance from the chord line to the lower surface, and r is the leading edge radius.