Hillary became interested in mountaineering while in secondary school. He made his first major climb in 1939, reaching the summit of Mount Ollivier. He served in the Royal New Zealand Air Force as a navigator during World War II and was wounded in an accident. Prior to the Everest expedition, Hillary had been part of the British reconnaissance expedition to the mountain in 1951 as well as an unsuccessful attempt to climb Cho Oyu in 1952. As part of the Commonwealth Trans-Antarctic Expedition he reached the South Pole overland in 1958. He subsequently reached the North Pole, making him the first person to reach both poles and summit Everest.