
From 1935, Hanna began to be involved in glider research and test gliding. In 1937 she was one of the first pilots to cross the Alps in a glider. Around this time she was ordered to report to a Luftwaffe testing station for duty as a test pilot, and thus began the type of flying for which she is best known. She flew a wide variety of types of military aircraft, including the Junkers Ju 87 Stuka and Dornier Do 17. Her obvious flying skill made her a star in the Nazi party, though she herself was not interested in politics and simply loved flying.
With the outbreak of war in 1939 Hanna was asked to fly many of Germany's latest designs. Among these were the rocket-propelled Messerschmitt Me 163 Komet, and several larger bombers, on which she tested various mechanisms for cutting barrage balloon cables. She became Adolf Hitler's favourite pilot and was one of only two women awarded the Iron Cross First Class during World War II.
In 1937 Hanna first flew an early helicopter, designed by Professor Focke of Bremen. Teaching herself to fly it, she thoroughly impressed its inventor, and was soon engaged to fly indoors, demonstrating the new flying machine to the public inside the Deutschlandhalle at the Berlin Motor Show. This gave her a love of helicopters which was to last all her life.
Hanna was captured and interned towards the end of the war, but afterwards settled in Frankfurt am Main, in Germany. She took up gliding again, and became German champion in 1955. Throughout the 1970s she continued to fly, breaking gliding records in many categories. She died in Frankfurt at the age of 67, on 24th August 1979, following a heart attack.