Called the Horten 229, the radical "flying wing" fighter-bomber looked and acted a lot like the U.S. Air Force's current B-2 — right down to the "stealth" radar-evading characteristics.

Fortunately for the world, the Ho 229 wasn't put into mass production before Nazi Germany surrendered in May 1945.

Northrop Grumman Corp. spent its own time and money using the original German blueprints to replicate the wood-and-steel-tube bomber, right down to its unique metallic glue and paint, at its facility in El Segundo, Calif.

Using radar of the same type and frequency used by British coastal defenses in World War II, the engineers found that an Ho 229, flying a few dozen feet above the English Channel, would indeed have been "invisible" to the Royal Air Force — an advantage that arrived too late for the Nazis to exploit.