Amundsen believed that the future of Arctic exploration was in the air. On 21 May 1925, accompanied by Lincoln Ellsworth, the son of an American millionaire, he took off northwards from Ny-Ålesund with two Dornier-Wal seaplanes, N 24 and N 25. They landed in an ice-free lead at 87°44’ N. One of the planes was damaged and ice closed up the lead. The two men spent three weeks making a 500-m long runway and managed to return to civilisation.
11 May 1926 the dirigible airship Norge started off on its transpolar flight over the Arctic with Amundsen, Nobile and Ellsworth onboard. The airship had been constructed by the engineer Umberto Nobile, a colonel in the Italian Air Force. They reached the North Pole after about 16 hours and landed at Teller in Alaska 14 May after a 72-hour flight. Their course had taken them through an as yet unexplored part of the Arctic and Amundsen could now say with certainty that it contained no large body of land. The last of the great unexplored blank spaces on the map had been eliminated.