Without any context, you might look at this photo and think, "that's a mockup of a modern stealth fighter jet" — perhaps a first stab at an F-22 or an F-35. But this is very different: what you're seeing here is Boeing's "Quiet Bird," a classified project from the early 1960s — yes, the early 1960s — to develop a military aircraft with an extremely low radar profile. That kind of stealth technology didn't end up seeing wide use in small military aircraft until the production of Lockheed's F-117 two decades later.

Foxtrot Alpha reports that it was provided details of Quiet Bird by Boeing, including a number of photographs and schematics, but that much of the information about its development has been lost over time. The aircraft never flew; in fact, it never made it beyond the half-scale model pictured here, which was tested at a radar facility in Kansas and found to be very stealthy indeed. The company filed a number of patents relating to stealth technology as a result of the Quiet Bird program, but that's about it: the US military wasn't interested in stealth fighters at the time, so the project was shelved.

Head over to Foxtrot Alpha for the full story.