Everybody was so interested in our recent episode about weird aircraft that we figured you’d like some more where that came from, and luckily there are lots and lots of weird aircraft!

The twentieth century was full of strange, experimental jets, but there have been plenty of other flying machines to choose from, too. And we’ve learned a surprising amount from them.

With this episode, we’ll see just how far people have drifted from your average plane, from gigantic flying ships to personal helicopters. Which are like personal pizzas, but way more dangerous. The Soviet Union’s Caspian Sea Monster and other crafts like it spend most of their time in the water, and they officially count as ships.

Unofficially, they’re totally just cool planes. At about 75 meters long and over 500,000 kilograms when fully loaded, the Sea Monster was the largest plane in the world when it first flew in 1966. Americans looking at satellite images quickly gave it its colorful name, though they also called it the KM, based on its Russian name.

Those Americans also noticed that the KM never seemed to fly high enough to register on conventional radar. It only ever skimmed across the surface of waters like the Caspian Sea. But it took years for them to realize that the KM never flew very high because it couldn’t.

It only lifted off at all thanks to the ground effect. Usually, part of the lift that lets planes fly comes from air getting pushed down as it flows past the wings. In return, that pushes the plane up.

But near the ground, that air can’t go any farther down once it’s below the wings. It just gets squished into the air that’s already there. The extra pressure from squishing the air pushes up on the wings even more than it would normally, giving the plane even more lift than usual.

The ground effect helps planes take off all the time, and it’s part of that floating or bouncing feeling that they can have during landing. And that extra lift provided by the ground effect was also just enough to keep the enormous KM in the air -- although it couldn’t fly more than twenty meters or so above the water. Unfortunately, it wasn’t exactly the safest aircraft.

During flight, the slightest wrong twist would plunge the KM’s gigantic wings straight into the water. That might have been what happened when the only KM ever built crashed and sank into the Caspian Sea in 1980, though the details are still murky. After that, the Sea Monster was never brought back, because by then, the Soviet Union had a few new ground effect planes.

Those flew into the 1990s before being retired, and there haven’t been many ground effect planes since then. But there has been talk for the last couple of years of Russia bringing the program. So soon, we might have another Caspian Sea Monster.

From one of the heaviest piloted planes ever to one of the lightest:. Please welcome the Gossamer Albatross, the first human-powered plane to cross the English Channel. People have dreamed of human-powered flying machines for centuries, ever since somebody flapped their arms around.

But by the early 1900s, most designs had a pilot pedal something like a bicycle to get them moving fast enough to lift off. No matter the design, though, the biggest challenge was always the same:. People and wings are heavy, and lifting that weight into the sky generally takes more energy than someone can muster.

The first big flap forward came in 1921, when champion cyclist Gabriel Poulain won 10,000 francs for his world-record, jaw-dropping… 11 and a half meter flight. The Gossamer Albatross didn’t come along until nearly 60 years later. But when it did, it flew some 3000 times farther than that.

Like with Poulain’s aircraft, the Albatross was also inspired by a cash prize. This time, the money was offered by industrialist and inventor Henry Kremer. He ultimately offered 200,000 dollars for the first human-powered flight from England to France -- a distance of 35.6 kilometers.

The Albatross was designed by engineer Paul MacCready, who had been the first to win another Kremer prize in 1977 with his bicycle-based Gossamer Condor. MacCready prioritized weight over everything, so he got rid of a lot of the heavier equipment that steadied or helped speed up other designs. This made his aircraft, both the Condor and the Albatross, pretty slow, but they were super-light, and that was important.

The Albatross was based on the Condor, but it used carbon fibers and Kevlar to save weight without losing the strength it needed to hold up during a flight across the English Channel. And at about 6:00 in the morning on June 12, 1979, pilot Bryan Allen lifted off and slowly flew away from the English coast. He endured leg cramps, dehydration, broken radios, and broken way-finding equipment during a flight that was slower and longer than expected due to strong cross winds.

But 2 hours and 49 minutes after takeoff, he and the Albatross landed in France -- ready to claim that 200,000 dollar prize. And today, even in our jet-dominated world, human-powered planes are still out there in the skies -- including more than a few inspired by the Albatross. In our last video, we talked about the X-29’s backward wings and the V-22’s folding wings.

But that’s nothing compared to no wings, like on Avro Canada’s VZ-9AV Avrocar: America’s flying saucer! At first, a saucer can seem like a great shape for an aircraft. Air goes over it the same way in every direction, so flying in any direction should provide the same amount of lift.

Engineers thought so, too. The Avrocar was supposed to be the prototype for a planned supersonic flying saucer that could cruise 30 kilometers above the ground. But don’t break out the tin foil just yet.

Tests with the Avrocar taught us that large, saucer-shaped aircraft are super impractical. Without wings, the only way the Avrocar could get off the ground was to suck air in the top and blast it out the bottom. But even with three jet engines, it could only rise a meter off the ground before there wasn’t enough of an air cushion to keep it stable.

And instead of zipping all over the place, it couldn’t move any faster than about 50 kilometers an hour. Now, the Air Force planned for their supersonic saucer to be the same shape, but with /six/ engines instead of three. They hoped those extra engines would get it going about 70 times faster once it was up in the air, so maybe there was still hope.

To test their modified design, they put the original Avrocar in wind tunnels to see what a saucer-shaped craft would do at very high speeds. They found that if the Avrocar could just go three or four times faster, the ground effect would help it take off and get higher into the air. Which would have been great news for the program, if dust kicked up from the ground didn’t constantly clog up the engines.

The wind tunnels also helped reveal a problem that stopped the entire program. Even if a saucer got high in the air and up to really high speeds, it would jerk around uncontrollably, and engineers couldn’t find a way to fix it. With so many more conventional planes that already worked better than a flying saucer, the U.

S. government suspended the Avrocar project in 1961, after just a couple years of testing. And plans for a supersonic flying saucer were canceled for good. At least, that’s what they /want/ you to think.

So far, we’ve seen one aircraft without an engine and another without wings, so why not one without either? Because that’s what came out of the Briegleb Glider Company in 1963, with the M2-F1. The original idea was to use light, wingless aircraft to glide astronauts home from space, instead of capsules with parachutes on them.

But even though that ultimately didn’t happen, that doesn’t mean the M2-F1 was a dud. Instead of wings, this craft had a rounded bottom and a flattened top, making it look kind of like a cone that got flattened on one side. Engineers had discovered in the 1950s that this shape generated lift without wings, just based on how air moved past both sides of the flattened cone.

And the M2-F1 took full advantage of that discovery. In early tests, it had to be towed behind a car because it had no engine of its own. And once the car reached about 190 kilometers an hour, enough air would be moving over the aircraft that it would start to fly.

After a few hundred successful tests, engineers moved from towing the aircraft behind a car to towing it behind another plane. This time, they released it about 3 and a half kilometers up so that it could glide down to the ground. And in all 77 of those tests, it again maneuvered and landed safely.

Even with capsules successfully serving the space program, NASA kept researching new wingless designs, anyway, to learn how different shapes glided through the air. Some were bigger than the M2-F1, some were heavier, and some even had their own engines. And many of the designs worked well, even going supersonic a couple times.

But these lifting bodies, as they were known, also had a couple pretty nasty crashes -- including one whose footage made it into the opening sequence of “The Six Million Dollar Man” … if anyone watching this remembers that show. We have so many other ways of getting in the air that there aren’t many wingless wonders these days. But one of their biggest legacies is still world-famous, despite entering retirement back in 2011.

Because even though they had wings, the landing style of the Space Shuttles was inspired in part by the M2-F1 and its descendants. If an aircraft without wings isn’t extreme enough for you, there’s the HZ-1 Aerocycle: a helicopter without any actual helicopter. It was developed during the 1950s, the golden age of ridiculous flying machines.

And it featured two spinning sets of blades that acted like a helicopter and lifted a soldier high into the air. The United States imagined giving them to soldiers so they could quickly move around in swarms and descend on a battlefield from above. But there were a couple of holes in this plan.

For one, these were just regular soldiers, not trained Air Force pilots. And each Aerocycle only fit one person on its pedestal. Each rider would also get only about 20 minutes of training -- basically, a crash course in how to not fall into the spinning rotor blades of death below you..

If nothing else, at least the Aerocycle was easy to steer. You controlled it almost like a Segway, by shifting your weight in the direction you wanted to go. And it wasn’t like there were /no/ safety precautions on there.

Each cycle’s pedestal, where the soldier stood while driving, had its very own harness! And early models even had airbags underneath to smooth out landings -- although those were later removed. The first test flights were done with professional pilots in 1955, and they, surprisingly, went off without a hitch.

Unfortunately, the next round of testing was with less-experienced pilots. And they didn’t go as well -- although it wasn’t really the pilots’ fault. A pair of crashes involved rotor blades smacking into each other as the Aerocycle flexed during flight, and another came on a windy day when the Aerocycle was too unstable to control.

Wind tunnel tests also showed that the Aerocycle would pretty much always be unstable in high winds. And those wind tunnel tests killed this incredibly dangerous project, just like they killed the Avrocar. The amazing aircraft we’ve talked about in these videos are just beginning of the creative, sometimes terrifying designs that fill aviation history.

But every one of these weird experiments, whether it failed on the launch pad or was used for decades, has taught us something about flight. They’ve helped us fly through the air faster and smoother than any bird ever could. Thanks for watching this episode of SciShow!

If you can’t get enough of cool aircraft, you can watch our episode about the future of air travel. ♪.