Abstract: An aerofoil 31, 43, 56 is provided by layers of material with at least one layer of the material being relatively stiff while other layers of material are less dense but are subject to less stress within the aerofoil. Thus, by judicious positioning of the stiffer layers of material an effective operational aerofoil is achieved, with the other layers of material having a lower stiffness but also lower mass so that the overall mass of the aerofoil is reduced. It will be understood by appropriate positioning of the layers of material it is possible to tune the aerofoil for deformation and vibrational response effects, particularly under impact loading from bird strikes etc.

Abstract: An aerofoil 31, 43, 56 is provided by layers of material with at least one layer of the material being relatively stiff whilst other layers of material are less dense but are subject to less stress within the aerofoil. Thus, by judicious positioning of the stiffer layers of material an effective operational aerofoil is achieved, with the other layers of material having a lower stiffness but also lower mass so that the overall mass of the aerofoil is reduced. It will be understood by appropriate positioning of the layers of material it is possible to tune the aerofoil for deformation and vibrational response effects, particularly under impact loading from bird strikes etc.