Designer Walter Horten had lost hundreds of Luftwaffe colleagues during the Battle of Britain in 1940, and he was keen to avenge their deaths by developing a plane that would be pretty much invisible to Britain's radar system.
He and his brother built and flew the prototype Ho 2-29 just before Christmas 1944, but the war ended before the plane could enter mass production.
The only remaining Horten 2-29 is kept hidden from public view at the Smithsonian's National Air and Space Museum's Paul E. Garber Preservation, Restoration and Storage Facility outside Washington, DC.
Did the plane truly have stealth capability against WWII radar? A team from Northrup Grumman built and tested a full-scale replica to find out.
Photo by Linda Reynolds/Flying Wing Films