Patent ID: 8529720

Claim:
A method for forming an aerofoil comprising: providing a first skin panel; providing a first web-forming membrane adjacent the first panel; selectively bonding part of the web-forming membrane to parts of the first panel; providing a second skin panel; providing a second web-forming membrane; selectively bonding parts of the second web-forming membrane to parts of the second skin panel; selectively bonding parts of the first web forming membrane to parts of the second web-forming membrane; arranging the panels together so that the first skin panel overlays the second skin panel with the first and second web-forming membranes arranged therebetween to define an aerofoil sub-assembly; heating the aerofoil sub-assembly to a temperature sufficient to effect plastic deformation of the panels and the web-forming membranes; and inflating the aerofoil sub-assembly, after the bonding steps and the heating step, to draw the first and second skin panels apart and to cause the first and second web-forming membranes to form webs internally of the aerofoil.