The professional estate of Prof. Tränkle (*1905 - †1996) covers the period from 1930 to 1965. It contains four notebooks with lecture notes and reprints of scientific journals. In 1963, Prof. Tränkle was appointed to the newly established chair of flight mechanics and flight control at the Institute of Aeronautics and Astronautics of the Technical University of Munich, which he held until his retirement in 1973.