A method for forming a metallic structure having a non-linear aperture includes providing a main tool having a formation surface corresponding to a desired structure shape of the metallic structure. The method also includes attaching a removable tool having a shape corresponding to a desired aperture shape of the non-linear aperture to the main tool. The method also includes depositing a layer of material on the formation surface using a cold-spray technique. The method also includes removing the removable tool from the layer of material such that the layer of material defines the non-linear aperture.