The thesis deals with the analysis of corrosion on the structure of a firefighting aircraft and consists of a theoretical and experimental part. In the theoretical part of the thesis, the basic concepts of corrosion are explained, including the mechanisms of corrosion formation, types of corrosion, and factors influencing its development. Methods of corrosion protection are described. Special attention is given to the impact of corrosion on the structure of the Canadair CL-415 firefighting aircraft and to the prevention of and protection against corrosion. The thesis also presents and comments on examples of corrosion damage on the mentioned aircraft. The experimental part of the thesis involved selection and preparation of test samples, testing in a salt chamber, testing in a climate chamber with a heated water tank, and electrochemical testing. The preparation of the test samples was carried out at the Aeronautical Technical Center, while the tests were performed at the Materials Protection Laboratory at the Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb.