Patent ID: 8419374

Claim:
A composite airfoil comprising: a three-dimensional composite core extending longitudinally and having a chord-wise direction, having a core in-plane thickness extending between opposing sides in a through-plane direction generally perpendicular to the chord-wise and longitudinal directions; a composite skin covering the opposing sides and having an exterior surface providing an airfoil contour, the skin having a total skin in-plane thickness corresponding to a sum of thicknesses through the skin in the through-plane direction from each of the opposing sides to their adjoining exterior surface, a sum of the core in-plane and skin in-plane thicknesses at a central portion of the composite airfoil being a total in-plane thickness, with the total skin in-plane thickness at the central portion being between 25% to 35% of the total in-plane thickness; and wherein the total skin in-plane thickness is 10% of the total in-plane thickness over a root from which the airfoil longitudinally extends.