De Lackner HZ-1 Aerocycle Strange Aircraft

This one man personal helicopter was designed as a reconnaissance aircraft for the Army. Unfortunately, it was hard to fly, and the thought of standing on top of an unguarded lawn mower blade wasn't very appealing to...anyone.

North American F-82 Twin Mustang Strange Aircraft

They say two heads are better than one, so why not apply the theory to airplanes? The "double P-51" was designed as a long range escort fighter in WWII, but the war ended before it was operational.

McDonnell XF-85 Goblin Strange Aircraft

The idea was this: the XF-85 would be carried in the belly of a Convair B-36 bomber, launch mid-flight to protect the bomber from enemies, then re-dock with the bomber using its retractable nose hook. Unfortunately, it was easier said than done, especially the re-dock procedure.

Northrup Tacit Blue Strange Aircraft

At first sight, it looks like part of a pine box racer competition, but this was actually a stealth testbed flown in the early 80s. The aircraft had a quadruple-redundant fly-by-wire system to keep it airborne.

Bartini Beriev VVA-14 Strange Aircraft

It looks like something out of Star Wars, but it was designed and flown here on Earth. The VVA-14 was a Russian ground effect aircraft designed to hunt US Navy submarines.

Mil V-12 Strange Aircraft

No one can build helicopters quite like the Russians, and their Mil V-12 takes the cake. The world's largest helicopter could carry up to 196 passengers, or 88,000 pounds of payload. However, its primary mission of deploying ballistic missiles became outdated as Russian missile technology moved forward in the 1970s.

Curtiss-Wright VZ-7 Strange Aircraft

The "flying jeep" was a unique concept, although inherently dangerous (there were no shrouds around the propellers). The aircraft was reportedly easy to fly, but never was able to meet Army standards.

Hiller X-18 Strange Aircraft

Is it an Osprey prototype? Actually, sort of. The X-18 was the first testbed for tiltwing and VSTOL technology. Unfortunately, the X-18 didn't handle wind gusts well, and the engines weren't cross-linked, meaning an engine failure would result in a crash.

Lockheed XFV Strange Aircraft

Lockheed's attempt at combining a helicopter and airplane yielded interesting results. The XFV did manage to transition from conventional to vertical flight, but its lack of speed and need for highly experienced pilots placed it on the chopping block.

Caproni Ca.60 Strange Aircraft

How many wings can we fit on this thing? The Ca.60 was a flying boat that served as a prototype for a 100-passenger trans-atlantic plane. It had 8 engines, 9 wings, and flew once, to an altitude of 60 feet. It promptly crashed into the water (fortunately, the pilot survived).

Vought V-173 Strange Aircraft

The "Flying Pancake" looks like it would have never taken flight, but it did, in 1942.

Convair F2Y Sea Dart Strange Aircraft

Is it a fancy jet-ski? Nope, it's the world's only supersonic seaplane. In the late 1940s, supersonic jets had too long of a takeoff roll to be used on aircraft carriers, so the Navy did the next best thing: put skis on the jet. Underpowered engines and violent vibrations during takeoff grounded (or watered?) this plane for good.

Goodyear Inflatoplane Strange Aircraft

Goodyear is great at making tires, but they may have taken this experimental project a bit too far. The all-fabric inflatable aircraft was designed as a rescue plane that could be dropped to downed pilots behind enemy lines. The project was cancelled by the army, because they couldn't find a "valid military use for an aircraft that could be brought down by a well-aimed bow and arrow."