This paper deals with a method to extract the free-state shape of aeronautical assembly components from part measurements independently of the assembly configuration of use. Knowledge of the free-state shapes enables to assess the geometrical conformity of an assembly through the assembly simulation using Finite Element Method (FEM). The component is measured, using optical means in a given configuration for which the setup is well-known. A coarse cleaning is thus applied on the measured data to obtain manipulative data in the CAD model frame. Meanwhile, displacements due to the measuring setup and to gravity are evaluated from the nominal geometry using FEM. Finally, the free-state shape, as a finite element mesh, is achieved by moving the nominal mesh nodes by a distance equal to the measured defect minus the evaluated displacement. The approach is applied to an aeronautical component.