Methods for forming protective coatings on aerospace components are provided. In one or more embodiments, the method includes exposing an aerospace component to a first precursor and a first reactant to form a first deposited layer on a surface of the aerospace component by a first deposition process (e.g., CVD or ALD), and exposing the aerospace component to a second precursor and a second reactant to form a second deposited layer on the first deposited layer by a second deposition process. The first deposited layer and the second deposited layer have different compositions from each other. The method also includes repeating the first deposition process and the second deposition process to form a nanolaminate film stack having from 2 pairs to about 1,000 pairs of the first deposited layer and the second deposited layer consecutively deposited on each other.