Partial differential equations are key to solving aerodynamics (Navier-Stokes, Euler, potential equations of motion) and structural dynamics ( for example, the vibrating string, beams in bending and torsion). The reader is encouraged to explore any paper that uses computational fluid dynamics and computational structural dynamics to see how these are used. For aerospace applications, the suite of American Institute of Aeronautics and Astronautics (AIAA) journals and the Journal of the American Helicopter Society (JAHS) include a number of these papers.