The B-2 Spirit blew more than a few minds when it made its public debut in 1988. But America's flying wing was not the first of such aircraft. In fact, one such plane nearly darkened the skies over Washington at the end of WWII with a nuclear present from the Fuhrer.
The head of the German Luftwaffe, Reichsmarschall Hermann Göring, was a notorious stickler, often demanding exceedingly stringent performance standards from the aircraft under his command. In 1943, he unveiled his most ambitious requirement set to date, quickly dubbed the "1000/1000/1000 rule". It dictated than any future aircraft purchased by the German air force must be capable of hauling a 1000 kg load over a distance of 1000 km at a speed of 1000 km/h. And given the state of jet engine technology at the time, that requirement eliminated just about every aircraft currently in development.
There was one however. A prototype built by brothers Reimar and Walter Horten and based on their dozen years of unpowered glider design and research. And it quickly caught the Reichsmarschall's eye and purse strings. He paid the brothers a whopping 500,000 reichsmarks (£1.72 million in 2014 GBP, adjusted for inflation) for it. It would become the Horten Ho 229, the world's first flying wing jet, as well as the first to incorporate stealth technology. Had it entered the fray, this long range bomber could have done to Washington DC what the Enola Gay did to Hiroshima.
The Ho 229's canopy on static display at the Smithsonian Image: Eric Long
The Ho 229, which is also commonly referred to as the Gotha Go 229 because Gothaer Waggonfabrik actually constructed them, were single seater long range bombers capable of carrying two 1,100 pound (500 kg), nuclear tipped bombs clear across the Atlantic, drop them on DC, then fly back to Germany.
The flying wing design—wherein all vertical control structures (i.e. the tail) are removed to decrease drag—was nothing short of revolutionary and promised the same degree of performance advancement that jet engines provided over turbo-props. The prototype 229 measured 26 feet long with a 55 foot wingspan. Its central cockpit was constructed from welded steel tubing but the wings were made from a pair of plywood panels glued together with a mix of adhesive, sawdust, and charcoal. It's conical inlet caps were crafted from multiple layers of carbon-impregnated laminate.
These materials were impregnated with charcoal dust as one of the earliest forms stealth. The coal's carbon content absorbs radar, thereby drastically reducing the plane's radar cross-section and making it appear much smaller than it really was, about the size of conventional twin engine prop aircraft of the day.
The jet was powered by a pair of 1,900 lbf Junkers Jumo 004B turbojet engines that propelled the aircraft up to and estimated 977 km/h (not quite what Göring wanted but could likely have been achieved in later iterations) with a 60,000 foot service ceiling.
But, as the first of its kind, the Ho 229 was plagued by development issues and the first prototype crashing multiple times. But the Luftwaffe was undeterred, fast tracking the plane's development and even going so far as to assign it to an active bomber wing. Luckily, the 229's development came too late to help the German War effort. By the time it entered production in early 1945, the Allies were already marching on Berlin. The Gothaer Waggonfabrik factory, where the planes were being built, fell in April of that year.
Though all but one of the 229 prototypes were destroyed before being completed, Operation Paperclip (which sought to spirit German scientists away to America at the end of the war) ensured that the technology was not lost. Today, the only Nazi jet prototype left on Earth is represented by a static model at the Smithsonian National Air and Space Museum's Paul E. Garber Restoration Facility in Maryland while the genuine item undergoes a piecemeal restoration. [Smithsonian - Wiki - Military Factory - Fiddler's Green - Horten Conservation]