An airfoil for flow control, comprising an outer skin in contact with an ambient air flow, wherein the outer skin extends between a leading edge and a trailing edge and forms two opposite sides (27a, 27b), and surrounds an interior space, and wherein the outer skin comprises a porous section in the area of the leading edge, a pressure chamber arranged in the interior space, wherein the pressure chamber is fluidly connected to the porous section, an air inlet provided in the outer skin, wherein the air inlet is fluidly connected to the pressure chamber and configured to cause an overpressure in the pressure chamber such that air discharges through the porous section into the ambient air flow, and an air outlet provided in the outer skin, wherein the air outlet is fluidly connected to the pressure chamber and configured to cause an underpressure in the pressure chamber such that air of the ambient air flow is sucked in through the porous section, wherein the air inlet and the air outlet are integrated in a common inlet/outlet device that is arranged in one side of the outer skin and that is configured to selectively let air in from the ambient air flow or discharge air into the ambient air flow, wherein the air inlet is formed as an opening that is flush with the outer skin, wherein the air inlet is formed by the inlet/outlet device comprising a door, the door is pivotable between a closed position where the ambient air flow is inhibited from passing through the outer skin and entering the airfoil, and an inlet position where the ambient air flow may pass through the outer skin into the airfoil, and in the closed position the door is flush with the outer skin, and in the inlet position a channel is formed between the door and an edge of the opening for ambient air flow to pass through the outer skin into the airfoil, characterized in that the door is inward-pivoting. an outer skin in contact with an ambient air flow, wherein the outer skin extends between a leading edge and a trailing edge and forms two opposite sides (27a, 27b), and surrounds an interior space, and wherein the outer skin comprises a porous section in the area of the leading edge, a pressure chamber arranged in the interior space, wherein the pressure chamber is fluidly connected to the porous section, an air inlet provided in the outer skin, wherein the air inlet is fluidly connected to the pressure chamber and configured to cause an overpressure in the pressure chamber such that air discharges through the porous section into the ambient air flow, and an air outlet provided in the outer skin, wherein the air outlet is fluidly connected to the pressure chamber and configured to cause an underpressure in the pressure chamber such that air of the ambient air flow is sucked in through the porous section, wherein the air inlet and the air outlet are integrated in a common inlet/outlet device that is arranged in one side of the outer skin and that is configured to selectively let air in from the ambient air flow or discharge air into the ambient air flow, wherein the air inlet is formed as an opening that is flush with the outer skin, wherein the air inlet is formed by the inlet/outlet device comprising a door, the door is pivotable between a closed position where the ambient air flow is inhibited from passing through the outer skin and entering the airfoil, and an inlet position where the ambient air flow may pass through the outer skin into the airfoil, and in the closed position the door is flush with the outer skin, and in the inlet position a channel is formed between the door and an edge of the opening for ambient air flow to pass through the outer skin into the airfoil,