Patent ID: 8172185

Claim:
An aerofoil body comprising: a leading edge, the leading edge including an attachment line being a region where air impinging on the region flows in a boundary layer spanwise along the leading edge and a duct, the duct having a duct entrance for receiving spanwise flow along the leading edge of the aerofoil body, wherein the duct is formed by the leading edge of the aerofoil body and a plate member attached over and around the leading edge, at a spanwise upstream end of the plate member the plate member being spaced from the leading edge to form with the leading edge the duct entrance which extends around the leading edge and has a width which extends over the range of positions of the attachment line and in that the duct further comprises a duct exit for discharging flow, the plate member abutting the leading edge of the aerofoil body at a spanwise downstream end of the plate member whereby the duct exit is disposed spanwise downstream of the duct entrance and is formed along a side edge of the plate member extending between the spanwise upstream and downstream ends thereof.