The F-117A Nighthawk is the worlds first operational aircraft designed to exploit low-observable stealth technology. A product of Lockheeds highly classified Skunk Works department the Have Blue program called for an aircraft that could enter enemy airspace without detection by radar. First conceived in 1978, it took to the skies in 1981 (rumour has it over Area 51) and operated under total secrecy until 1988 when its existence was made public.