US Admiral Richard Byrd, with the assistance of his first pilot Bernt Balchen, became the first person to fly over the South Pole on November 29, 1929. However, it was not until 31st October 1956 that men once again set foot at the Pole, when a party led by Admiral George Dufek of the US Navy landed there in a R4D Skytrain (Douglas DC-3) aircraft. The US Amundsen-Scott South Pole Station was established by air over 1956–1957 for the International Geophysical Year, and has been continuously staffed since then by research and support personnel.