Paul Wilhelm Bäumer, also known as The Iron Eagle, was a German fighter ace in World War I. Bäumer died in an air crash at Copenhagen on 15 July 1927, age 31, while test flying a Rohrbach Ro IX fighter. Rohrbach's test pilot had already been involved in a spinning accident, and Bäumer, acting as a freelance test pilot, continued the testing and died after the aircraft entered a spin and crashed in the Øresund.