Horten 229, the fly wing

In the final months of World War II, American troops discovered a top-secret facility in Germany with an advanced batwing-shaped jet fighter. If Nazi engineers had had more time, would this jet have ultimately changed the outcome of the war? In this National Geographic documentary they rebuild a jet discovered in a top-secret German facility during the final months of World War II - the Horten 229. This is not only an insight into Nazi technology that was years ahead of its time but also an insight into the work of the people reconstructing it who usually work on secret X Projects

 

During the First World War, an attempt to reduce the visibility of military aircraft through the experimental use of "Cellon" plastic transparent covering material resulted in single examples of the Fokker E.III Eindecker fighter monoplane, the Albatros C.I two-seat observation biplane, and one German heavy bomber design, the Linke-Hofmann R.I all being covered with the "Cellon" material; the latter two aircraft had all-wooden structures covered with the "Cellon" material, which degraded rapidly in direct sunlight and were not proceeded with any further.

Nearly three decades later, a more serious attempt at "invisibility" was tried with the Horten Ho 229 flying wing fighter-bomber, developed in Germany during the last years of World War II In addition to the aircraft's shape, which may not have been a deliberate attempt to affect radar deflection, the majority of the Ho 229's wooden skin was bonded together using carbon-impregnated plywood resins designed with the purported intention of absorbing radar waves. Testing performed in early 2009 by the Northrop-Grumman Corporation established that this compound, along with the aircraft's shape, would have rendered the Ho 229 virtually invisible to the top-end HF-band, 20-30 MHz primary signals of Britain's Chain Home early warning radar, provided the aircraft was traveling at high speed (approximately 550 mph (890 km/h)) at extremely low altitude (50–100 feet).

We had to admint the level of engineering that these guys had..... unbelievabel the level to RCS