#4. XP-82 Twin Mustang
"The P-51 Mustang is a pretty awesome plane. But what could be even better? Hmm ... wait, we've got it! Take two P-51's, weld them at the wing and then ... well, that's actually about it." And thus was born the XP-82.
It was the only aircraft ever to inspire a Doublemint commercial.
Believe it or not, the Twin Mustang actually did quite well. With one cockpit dedicated to flying, and the other dedicated to sonar or weapons, the Twin Mustang was efficient, alert and did tag=team damage to those who dared to attack the Siamese twin of the Air Force freak show. Also, it was perfect for when the pilot and co-pilot hated each other, or when one of them smelled bad.
"I keep telling you Jim, that hippy salt deodorant does fuck all for your B.O."
While early designs had some issues getting into the air and pilots complained that that flying from that off-center position proved somewhat difficult, it passed testing just after World War II ended. They served well in Korea, escorting large aircraft and occasionally taking out Chinese planes. But replacement parts became hard to get as production for other planes began stepping up with the growing Cold War. By the end of the Korean War, the Twin Mustang fad was over.
"Screw it. Let's sell them all to Bespin."
#3. XFV-1 "Pogo"
Vertical liftoff planes (that is, planes that can take off straight up and don't need a runway) are commonplace now, but getting there took a lot of insane trial and error. For instance, you have the XFV-1, one of two competing designs that did the same thing: sit on their tails and buzz straight into the sky.
That other plane looks sort of embarrassed to be seen with it.
After a brief test flight in 1953, its first full flight came in 1954, and defied all expectations by actually taking off vertically and hovering.
So what's the problem? Watch the video. The ass-down method seems fine for taking off, but then you have to land. It forced the pilot to land blind, or try to look back over their shoulder as they carefully -- carefully -- eased the tiny, ridiculous little wheels back onto the pavement. Imagine trying to do that in an emergency, or onto the deck of a battleship bobbing up and down in rough seas (which is, in fact, what the XFV-1 was designed for).
"Shit. Nobody brought a ladder?"
The program ended in 1955, and the only XFV-1 ever built went to a museum in Florida.
#2. Aerospacelines Pregnant Guppy
All right, let's all just admit now that we apparently have no clue how the principles of flight actually work. If that thing can catch air, then apparently you can just slap wings and propellers onto any old thing and you're up in the clouds.
We're going to go ahead and call "Photoshop."
The Aerospacelines 21024V was created out of necessity. NASA needed a way to get huge Saturn V parts from California to Texas and Florida for the upcoming moon landings. So, they bought a Pan Am jet and lit their blowtorches. The top of the plane was extended up over 10 feet, the cabin was bloated out and the entire back of the plane was detachable for easier loading of huge cargo.
This would have made a fantastic Micro Machine playset.
When it rolled out, it was immediately called the "Pregnant Guppy" because the name obviously makes complete sense (guppies are enormous and give birth through their brains, right?). Van Nuys airport officials in California were so nervous about the thing crashing that each time the plane took off, they called police and fire officials "just in case."
But the Pregnant Guppy was safe, and even spawned a few other guppy planes, such as the super guppy and the wonderfully named Sky Monster. The guppies were in regular NASA use until the end of the 1970s.
Somehow, we expected more fangs.
#1. SNECMA Coleoptere
And ... we owe that other vertical liftoff plane from earlier an apology. This is the far more insane version France came up with.
The Coleoptere (French for "annular" or "cylindrical") had an even more unusual design than the XFV-1. But if you can believe it, having an enlarged bottom and retractable short wings actually helped during early trials. Well, it helped when taking off, anyway.
They didn't call it the "Flying Nipple." But they should have.
Unfortunately, they forgot about the whole "flying" aspect, which if you think about it, is pretty important to an aircraft design. Test pilots said the plane was extremely unstable during flight, which probably had something to do with having no real wings to speak of.
"So ... what if I want to go any direction but 'up'?"
On only its ninth flight, the Coleoptere crashed and burned, at which point the French military entered the "what were we thinking?" phase of the experimental aircraft design cycle. The program was ended in the early 1960s, and nothing that looked remotely like it was ever attempted again.
For more head-scratching designs, check out 7 Planes Perfectly Designed (To Kill The People Flying Them) and 7 WTF Military Weapons You Won't Believe They Actually Built.