In 1942, a Russian fighter pilot name Alexey Maresyev was shot down by Germans and crash-landed behind enemy lines. His legs were badly injured, and it took him 18-days to get back into Soviet territory. Both his legs had to be amputated, and he spent a year getting used to his prosthetics before flying again. Shortly after returning to the air, he shot down three German fighters in a single dogfight.
Source: Unbelievable Facts