He was a member of the
Soviet-German scientific expedition to the
Pamir Mountains in 1928. On that expedition he made the
first ascent of
Lenin Peak with
Karl Wien and on 25 July 1928. At that time the mountain had the name Kaufman Peak and, with Schneider's ascent, it became the highest summit reached in the world. Because of poor weather and snow conditions they failed to climb Kangchenjunga but the party did make the first ascent of four 7000m peaks. Those included
Nepal Peak , which Schneider ascended by himself and
Jongsong Peak which he climbed a few days later with . In 1932 he made the first ascent of
Huascarán Sur , the highest mountain in
Peru, on 20 July 1932. It has been written that the 1932 expedition, led by the geographer
Hans Kinzl, "made Peru's ranges known to the mountaineering world" and it was "the year that inaugurated modern climbing in Peru". He went to
Pakistan in 1934 with the
Austro-German expedition attempting to make the first ascent of
Nanga Parbat. On that expedition he became one of a large group of climbers trapped by a storm at . After spending two nights waiting for the storm to abate Schneider and were deputed to lead the party down to lower levels. They took three
Sherpas, the other three German mountaineers were to follow them with the rest of the Sherpas. When Schneider's group reached easier ground the party unroped and Schneider went ahead with Aschenbrenner, they expected the Sherpas to follow closely behind but they became separated and the Sherpas ended up spending two more difficult nights out in the storm before rejoining Schneider and Aschenbrenner at a lower level. The three other German mountaineers, including the expedition leader
Willy Merkl, and eight Sherpas also struggled in their descent, the three Germans and six of the Sherpas died in the struggle. Schneider and Aschenbrenner were later accused of abandoning the other members of the party. Some commentators felt that "he was treated with great injustice", He returned to Peru, with Kinzl and others, in 1936. They spent four months mountaineering and carrying out geographical and topographical work in the
Cordillera Blanca and the
Cordillera Huayhuash. During the course of that expedition Schneider and made first ascents of
Quitaraju via the west ridge on 17 Jul 1936 and the first ascent of
Siula Grande on 28 July 1936. The Peruvian expeditions of 1932 and 1936 formed the basis of the book "Cordillera Blanca". Schneider suffered severe
frostbite during a winter ascent of the Biancograt on
Piz Bernina. This was the end of his serious mountaineering, it led to the amputation of all of his toes and the middle section of his foot in 1939. When he ascended
Lenin Peak in 1928 he set the
world altitude record for the highest summit reached. He broke that record himself in late May 1930 when he made a solo ascent of Nepal Peak, and then for a third time when he and Hoerlin made the first ascent of
Jongsong Peak just a few days later on 2 June 1930. ==Cartographer==