In 1928 he rescued Umberto Nobile after Nobile"s airship crash on the ice north of Spitsbergen. He was later promoted to captain in the Swedish Air Force. Before joining the airforce, Lundborg participated in the Finnish Civil War in 1918 and in the in 1919–1920.
Lundborg was killed during a test flight of the Jaktfalken airplane at Malmslätt in 1931.
He is buried in Linköping, Sweden.