Abstract: A high lift stepped aerofoil section, incorporating a leading edge 1, trailing edge 3 and a step 2 to provide a higher vertical component in its construction; the aerofoil has greater perceived root thickness giving greater lift through compression 4 on the aerofoil under surface. The section has high pressure area 5 below the aerofoil and low pressure area 6 above the aerofoil. The aerofoil has much higher strength on all axes than conventional aerofoil sections.