• Visit our partners: Our Partners:
  • Visit our partners: Our Partners:

The Most Unusual VTOL Vehicles of the Last 100 Years

Vertical take off and landing, or VTOL, is a trait prized in aerospace. The ability to ascend or descend at a straight trajectory, without the need for a runway and all the space that requires, is something that engineers have poured countless hours and dollars into trying to make reality. Today, VTOL aircraft are far less rare, but are still a notable sign of whether a military is considered state of the art or not.

There are some great designs to choose from when it comes to VTOL, such as the V-22 Osprey, the Harrier Jump Jet, or the F-35, but we’re not going to talk about those today. Instead, we’re going to delve into the history of aviation designing all the way back to when VTOL was first explored as a concept, and bring you some designs that, rather than inspiring interest, instead inspire interest as to how someone even came up with this. These are some of the weirdest VTOL designs in aviation.

Lockheed XFV / Convair XFY

Our first entry has us already bending the rules of this list, because this is actually two planes in one slot. Don’t worry, you’re still getting five title cards; we’ve only done this because these two designs are siblings, born of the same project.

Following World War II, the United States was faced with something of a problem. The war had demonstrated the vulnerability of surface ships, such as convoys, to aerial bombers; with the advent of jet-powered aircraft with huge ranges, this vulnerability was only going to get worse. The American Navy was undoubtedly the most powerful navy on the planet, sporting several top of the line aircraft carriers which could launch interceptors to defend vulnerable ships, but carriers are obviously expensive, and they couldn’t be everywhere at once.

Vertical display of the XFV-1 Prototype at Florida Air Museum at Sun-n-Fun
Vertical display of the XFV-1 Prototype at Florida Air Museum at Sun-n-Fun. By WatchmanDS, is licensed under CC- BY-SA

So, the US armed forces decided to study an as of yet fringe corner in the field of aeronautics – VTOL. The original idea was to put VTOL aircraft on ships that weren’t carriers, to act as a first line of defense against aerial attack, in order to buy time for proper aircraft to scramble in response. There was just one problem: those aircraft didn’t exist yet.

No matter. In May of 1951, a pair of companies named Lockheed and Convair were awarded contracts to make those theoretical aircraft a reality. The contract stipulated that both companies were to create two fighter designs, although they only managed one each because, again, this was the 1950s and the entire field was still a work in progress.

Nevertheless, they did the work, and each came up with their own design – the Lockheed XFV, nicknamed “Salmon”, and the Convair XFY, nicknamed “Pogo”. Their designs were remarkably similar to each other, where the plane sat on its tail end and would take off by going straight up, helped by the two sets of three propellors built into the cone of the plane. Then, once off the ground, it would transition from vertical flight to horizontal flight.

These types of planes are referred to as “tailsitter” aircraft, for obvious reasons, and you may have noticed that they aren’t really a thing nowadays. That’s because tailsitter aircraft generally have to be landed on their tails again, which… well. Imagine trying to back into a parking spot, except you’re in a plane, and your body is at a 90 degree angle, the damn thing won’t sit still, and the insurance rate rises to literal death if you mess up. This problem became apparent during test flights, and it was determined that only the most experienced pilots would be able to use either design, which rather killed the whole rationale of putting these planes on every smaller warship.

What’s more, the designs had a maximum speed of around Mach 1, and jet aircraft were rapidly exceeding that around this time, to almost Mach 2. This put the planes at a decisive disadvantage, and it was determined that the project had too many downsides and not enough upsides. And so, it was scrapped, but everything has to start somewhere, at least. And speaking of which….

SNECMA Coléoptère

Our next entry takes us to France, around the same time as the XFV and XFY were being tested in America. The United States was not the only country to be testing the concept of VTOL, and France, which has often been iffy on American hegemony, was eager to create some designs for itself. But, as stated before, jet engines were becoming more and more powerful with time. This created problems, but also opportunities for more experimental designs, and one engine manufacturer, SNECMA, built a “wingless vertical takeoff design” for their engine in 1956, called the Atar Volant. Basically, they took their engine, wrapped it in a rocket fairing, and called it good.

However, while they were designing the Atar Volant, some interesting work was being done by an Austrian engineer named Helmut von Zborowski. If you’re thinking, “Hang on, that name doesn’t sound very Austrian,” you’re right. He was born in 1905, in the Czech Republic, when it was still a part of Austria-Hungary. But he called himself Austrian, so yeah.

Zborowski’s work was varied; he was actually involved in the creation of the V-2 rocket with Wernher von Braun. After World War II, he moved to France and focused his attention on the concept of VTOL. He came up with a design for an annular wing, as in a wing that goes around the fuselage of the aircraft in a sort of doughnut shape. An odd design, to be sure, but it caught the attention of SNECMA’s team, and they integrated this into their own efforts for a VTOL craft. The final result was the C.450 Coléoptère, or “Beetle”, completed in 1958.

Now, the first thing that catches your eye about this plane is that it is dummy thick. That’s the annular wing, attached to the core of the plane, and the idea was that the wing would function as a big ramjet engine, propelling the aircraft to supersonic speeds and making it an ideal interceptor.

In any case, you wouldn’t be the first to notice the wing; the look of the aircraft caught the attention of both the public and aircraft designers around the Western world. There’s even speculation that the design prompted the US Navy to make a contract for an American company to make something similar. But that’s only speculation, because the Coléoptère turned out to be a bit of a deathtrap.

Problems emerged almost immediately. The engine shook violently, making radio communication on the ground difficult to understand over all the noise. That means no air-traffic control. The craft also slowly spun on its axis while hovering vertically, which made landings rather difficult; in fact, it was declared that “dead stick” landings, whereby the plane loses propulsion power and is forced to land, were impossible. The controls were almost unworkable; one engineer described it as, “like a bicyclist trying to keep his balance while he’s stopped”. The test pilot, Auguste Morel, reported as much while trying to land the plane. Basically, if you’ve ever played the air refueling missions in Ace Combat 7, it was like that, but for real life.

The plane never actually transitioned to horizontal flight, since it was deemed too dangerous. Overall, eight successful test flights were conducted, with Morel at the controls each time, and it was on the ninth flight that things went very wrong. He lost control of the craft while trying to transition to limited horizontal flight, and was unable to regain it. Morel made the choice to eject, escaping the rapidly descending craft at only 150 meters above the ground (492 feet). He survived, albeit with some bad injuries; the aircraft was totally destroyed. Following this incident, the project was shelved, and no test flights were made again. And so, we bid farewell to this truly dopey looking airplane.

VJ 101

Our next entry takes us to West Germany. At the same time as the US and others were developing and testing VTOL technology, West Germany was doing nothing of the sort. That was because, until 1957, West Germany had been banned from operating or developing combat aircraft, because of the whole World War II thing. But once that restriction was lifted, the country made it clear that it wanted its own crack at the tech. To that end, three German aviation firms – Dornier, Heinkel, and Messerschmitt – received an official request from the West German government to pursue the tech.

The X-1 Prototype exhibited at the 1964 Hanover Air Show
The X-1 Prototype exhibited at the 1964 Hanover Air Show. By RuthAS , is licensed under CC-BY

West Germany grasped, better than most, that a VTOL aircraft needed to match the performance of non-VTOL aircraft in order to be worth the effort. To that end, a number of different approaches were taken, relative to the efforts of France and the United States. To start with, the German defense ministry deliberately withheld a contract for the plane in order to incentivize multiple companies to work together on the project. Second, the engine manufacturer, MAN Turbo (which is an amazing name for an engine company), partnered with the British Rolls Royce to jointly develop an engine for the eventual plane.

It was in 1959 that these efforts started to coalesce. Heinkel and Messerschmitt formed a consortium with a third company, Bölkow, to merge the effort for a test plane; Dornier went off to make their own model, the Do 31. This consortium, called Entwicklungsring Süd, or EWR, was contracted to make two experimental VTOL aircraft, using the MAN Turbo/Rolls Royce engine. The design that they came up with was the VJ 101.

At first glance, the plane doesn’t look particularly unique. But look a bit closer, and you can see the design is rather unconventional. Today, we’re familiar with the so-called “tiltrotor” concept, most famously used in the V-22 Osprey. The rotors of the craft can tilt, big surprise, from being vertical to being horizontal, shifting the aircraft’s flight mode. The VJ 101 was of a similar mind, except it utilized this tilt functionality in its jet engines – a “tiltjet” interceptor.

Here’s how it worked. The engines were positioned at the wingtips, as opposed to being fitted to the undersides of the wing, and were capable of rotation from facing downwards to facing horizontally, depending on what type of flight was needed. In addition to that, two further engines were installed within the fuselage itself, facing downward; these lift jets would supplement the main engines during takeoff. If that sounds familiar, it’s because the modern F-35 does something very similar, albeit with a single superpowered engine instead of four dispersed ones.

VJ 101 Top View
VJ 101 Top View. By Jaypee, is licensed under CC-BY-SA

Speaking of modern arrangements, the VJ 101 also included an electronic flight control system as opposed to an analog system, which was something of a luxury at the time. This was a big upgrade, as a “fly-by-wire” system offered better control during hovering, something which had plagued many previous designs. The computer also covered all of the difficult parts, such as the altitude while hovering and the transition from vertical to horizontal flight, all of it adding up to quite an advanced piece of hardware.

Testing began in 1963, and the plane performed quite well for itself, especially relative to some other designs at the time. It performed dozens of successful test flights, including full transitions to horizontal flight from a vertical takeoff, and it earned the distinction of the first VTOL aircraft to break the sound barrier.

So, what happened with this plane? Well, despite being a successful demonstration of the concept of VTOL as well as an overall well-designed plane, politics ended up killing the project. The German government, historically averse to spending money, and doubly so for spending money on the military, decided that they didn’t want to keep paying for such an expensive project. Add in an unlucky crash during a test flight, and the writing was on the wall; the project was cancelled in 1968.

Despite that, the VJ 101 stands out as a remarkably successful design when compared to contemporary efforts. Some of its design concepts live on in cutting edge fighters today, including the aforementioned F-35, which is just as much a computer as it is an airplane. Success, after all, is built on what comes before.

The Flying Jeep

Once again, we’re bending the rules with this entry, because again, it’s actually three models of very similar design. With that said, we’re still in the 1950s, the US armed forces are still testing VTOL, but with this next contract, they go a little bit further. In 1957, the U.S. Army Transportation Research Command issued a contract for a so-called “flying jeep”. What’s a flying jeep, you ask? Well, it looks like this. It was an open cockpit helicopter-like vehicle, and the idea was to make something small and intuitive enough that it could be operated by just about anyone, just about anywhere. And yes, it does look like something straight out of Battlefield 2042.

The picture you see specifically is the Curtiss-Wright VZ-7, which was actually the second model in the competition for creating this vehicle. The first, the Chrysler VZ-6, performed rather poorly, being both overweight and underpowered – quite relatable problems, all things considered. These problems came from the fact that it was designed somewhat like a hoverboard, with two propellors, one on the front and one on the back. Even if you aren’t an engineer, you can probably sense, at least a little, that a design like that isn’t very stable. And it wasn’t – during one test flight, the craft actually flipped over and crashed. That was imitating Battlefield a little too much.

The VZ-7 performed somewhat better, in that it didn’t fail at the basic level. This design had four propellors instead of two, fixing the stability problem, and control of the vehicle was maintained by changing the thrust of each propellor, depending on where the pilot wanted to go. Test flights were promising, but the craft didn’t meet the standards that the Army was looking for, and so it was sent back to the manufacturer. What those standards were, exactly, is an open question.

It should be noted that there’s very little information on most of this, other than “it was real”. To give you an idea, Wikipedia lists the test flights of the VZ-7 as 1958, question mark. It gets even more confusing, because the VZ-6 supposedly had its first test flights in 1959, despite it being earlier in the series… you get the idea, it’s a messy timeline.

The last model in this competition was the Piasecki VZ-8, completed in 1959. This was probably the most complete design, returning to the two rotor model of the VZ-6 and improving upon it to make it more stable. It also made space for a crew of two, rather than just one; now the pilot of the craft could have a co-gunner, because why not. And it worked well, with test flights showing it to be superior to both the VZ-6 and VZ-7. Granted, not flipping over is a low bar to clear, but still. It was stable in flight, and it was capable of rising to several thousand feet if needed, while being able to fly close to the ground to avoid radar.

Alas, it was not to be, as the Army evaluated the entire Flying Jeep concept and determined that it was “unsuitable for the modern battlefield”. There’s another video game joke in there somewhere, but the writer’s not being paid enough to find it.

The Army determined that the craft was too vulnerable to anti-aircraft weaponry, and didn’t offer sufficient protection for its pilot, as in, it offered no protection to its pilot. So, if it gets shot at, which tends to happen to military aircraft for some reason, you’ve got a problem. It was decided that the Army would focus on conventional helicopters instead, and so the flying jeep was shelved. Despite that, it has a certain charm to it that lingers after all these years. Imagine if everyone had one of these, like they predicted back in the 30s and 40s. …Actually, that’s a terrible idea, never mind.

Avrocar

We’re still in the 1950s for our last entry, if you can believe that. We’re also still with the US military, although we now have Canada making an appearance. In 1947, a man by the name of John Carver Meadows Frost, nicknamed Jack Frost, joined a Canadian aircraft manufacturing company by the name of Avro Canada. Frost was an engineer in aeronautics, having shown a passion for the field since his schoolteacher had taken him up in a biplane as a teenager, which probably makes him the coolest teacher ever. Yeah, yours might have bought you school supplies when you couldn’t afford them, but did they ever give you a ride in an airplane? I didn’t think so.

Avro Canada VZ-9AV Avrocar on display in the Research & Development Gallery at the National Museum of the United States Air Force.
VZ-9AV Avrocar on display in the Research & Development Gallery at the National Museum of the United States Air Force. By KLaRock, is licensed under CC-BY-SA

Anyways, Frost showed a dedication for experimental aircraft, designing Canada’s first jet fighter, the CF-100, and also being involved in the designs for the de Havilland Hornet and Vampire fighter jets. But it was at Avro Canada that he started to get into the fringe of what was doable. He came up with a design for a VTOL aircraft shaped like a disk, with several outward-facing jet engines in a circular frame, powering a central turbine and blowing air outwards and downwards to provide lift. Basically, he designed a flying saucer.

Now, if you think that sounds too weird to be taken seriously, you obviously don’t get it yet. The US Army became interested in Frost’s design, and gave him money to create prototypes for it. Since they were still running their flying jeep program at this time, the Avrocar, as the design came to be known, was entered in as the VZ-9, placing it directly past the last entry for the flying jeep.

There were some significant benefits if the project panned out. Frost’s design was extremely modular, originally consisting of six jet engines in a circular frame, surrounding the cockpit. That meant that the parts were more easily mass-producible than conventional aircraft like jets or helicopters. The VTOL capability of the craft was, of course, a huge motivating factor, and that was even before you factor in that Frost envisioned his design being capable of moving at three times the speed of sound, and having an upper ceiling of 100,000 feet in the sky. To put into perspective just how crazy that sounds, the F-22 Raptor, one of the most advanced jet fighters in the world, has a max speed of just over two times the speed of sound, and an upper ceiling of 65,000 feet.

Those aspirations turned out to be just as unrealistic as they first appeared. Frost’s original design, despite receiving funding, didn’t pan out, and he was forced to cut the number of engines to three, placed tangentially to each other. He also was forced to place the cockpit on the outer rim of the vehicle, rather than the center, which made control a bit awkward. And controls, just like everything else on this list, would turn out to be a big problem. Test pilots described the Avrocar as “like trying to balance on a beach ball”; the craft would wobble and become unstable as the centers of mass and pressure changed, which in turn made the craft even more unstable in a vicious cycle of wobble.

Stability wasn’t the only problem; turning the craft around was slower than you might imagine for a disk-shaped plane – five seconds clockwise, eleven seconds counterclockwise, due to the spinning of the turbine. Since planes live or die on being able to outmaneuver their opponents, this rather limited the Avrocar’s planned dogfighting capabilities.

Frost attempted to address these problems by adding wings and a tail, creating a kind of discount Starship Enterprise, but by then the age of experimental VTOL was coming to an end, as militaries realized that helicopters were just the more reliable option and traditional jet fighters were here to stay. And so, the Avrocar was shelved and eventually scrapped. But it lives on in our imagination, and we have to give credit to people like Frost who come up with such ingenuity as a real-life flying saucer.

The Skies As They Are

Today, VTOL is a common thing, just another fancy trick that military hardware can do. But it’s worth remembering the sheer amount of effort, money, and brainpower that it took to get to that point, as well as the projects that didn’t pan out. Behind every modern piece of equipment, there’s several failed ones, which just goes to show that maybe you don’t need to get things right the first time, every time. It certainly helps, though. I mean, a flying jeep? Come on, now.

Related Articles

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Stay Connected

48,134FollowersFollow
452,000SubscribersSubscribe

Random Article

00:13:53

Weapons that Changed Warfare: The Trebuchet

Once upon a time, if you lived in a castle, you were pretty safe. There might be a war waging all round you, with...

Latest Articles