Abstract: Eddy current inspection of aging aircraft has currently achieved new developments with the introduction of Magneto-Optic Imaging(MOI).Finite element modeling of eddy current magneto-optic imaging is invoked in this paper and applied to a typical defects of aircraft configuration,such as a flaw initiating under the cap of a fastener used to connect two aluminum layers of the aircraft skin.Simulation results revealed that the change in the vertical component of the magnetic field is noticeable for this configuration,and that MOI can be used to detect hidden flaws covered by the fastener cap.