Von Greim was a legend. Renowned for his fearlessness in battle, in World War I he had recorded twenty-eight kills. In the 1920s and 1930s he was considered one of the top pilots in Germany and performed a variety of flight-related jobs, including exhibition dogfights against fellow World War I flying ace Ernst Udet. When Adolf Hitler needed a pilot to fly him from Munich to Berlin for the Kapp Putsch coup attempt in 1920, he chose Robert Ritter von Greim for the job. In 1926, von Greim was hired by Chiang Kai-shek to set up the Chinese air force in Canton, China. Returning to Germany, von Greim opened a flight school, located at the top of a mountain in Galgenberg, two miles from where Hubertus Strughold taught aviation medicine to college students.
Strughold hired von Greim to teach him how to fly, paying him six marks per lesson. The two men became fast friends. In Robert Ritter von Greim, Hubertus Strughold found a brilliant match—another man willing to push pilot performance to the edge of unconsciousness. The men would strap themselves into harnesses in von Greim’s open cockpit airplane and fly loops and rolls in the skies over Galgenberg. Strughold kept track of their physiological reactions to extreme flight, seeking answers to questions. Can a man draw a straight line while flying upside down? Can a pilot mark a bull’s-eye on a piece of paper immediately after a barrel roll? With how little oxygen could a man legibly write his name? How far up can a man fly before his vision fades? Von Greim was challenged by Strughold’s strange requests, and he was willing to fly faster and higher as his new young physician friend recorded data on von Greim’s pilot performance and physical capabilities in the air. Strughold knew his tests were original and hoped they would attract interest from the United States. In 1928 his wish came true when he received a prestigious fellowship from the Rockefeller Foundation. Strughold packed his bags, boarded the SS Dresden, and headed to New York.
Hubertus Strughold took to America like a fish to water, he later explained. As a Rockefeller Foundation fellow at the University of Chicago, he was at the center of the music scene in the roaring twenties. Listening to jazz music was his favorite pastime after flying. In Chicago he attended vaudeville shows, parties, and dances and became fluent in English. He loved to drink and almost always smoked. His thick German accent distinguished him from everyone else around and made most people remember him. His first scientific paper in English was on oxygen deficiency and how to revive a heart using electric shock. For research he used dogs as test subjects, importing them from Canada at a time when experimenting on dogs from the United States was illegal. Strughold attended conferences in Boston and visited the laboratories at Harvard, at the Mayo Clinic in Minnesota, and at Columbia University in New York. And he met and became friendly with American aviation medicine pioneers like Harry Armstrong.
The Rockefeller fellowship lasted only a year. Back in Germany, Strughold and von Greim took up where they left off. Von Greim was now flying a double-decker Udet Flamingo aircraft, an aerobatic sports biplane made of wood. To determine how many g-forces a man could take before his eyeballs suffered damage, the two men would climb high in the air, then dive down toward the ground until one of them blacked out.
Von Greim’s longtime friend and colleague Adolf Hitler took power in 1933. In secret, von Greim was called upon by Hermann G?ring to rebuild the German Air Force, in violation of the Treaty of Versailles. Through his personal friendship with von Greim, Strughold ingratiated himself into this inner circle of Nazi power. In 1935 he was offered a job that would shape the rest of his life. As director of the Aviation Medical Research Institute of the Reich Air Ministry in Berlin, he was now in the uppermost echelon of Luftwaffe medical research. The lab, located in the suburb of Charlottenburg, featured a state-of-the-art low-pressure chamber and a ten-foot centrifuge in which test subjects could be exposed to varying degrees of gravitational pull. The chamber could take both apes and humans to between fifteen and twenty Gs.