'X Planes' investigates the highly secret world of spyplanes, advanced aircraft projects and the US Air Force's so-called "black programs". From the final days of World War II, when the Nazis planned to launch rockets on New York from submarines in the Atlantic, to aerial combat over the USSR in the 1950s and 60s, to the rumoured use of "alien technology" by the USAF, David Oliver and Mike Ryan reveal what's really out there . . .
