From cities in the sky to robot butlers, futuristic visions fill the history of PopSci. In the Are we there yet? column we check in on progress towards our most ambitious promises. Read the series and explore all our 150th anniversary coverage here.
When it came to futuristic cars, magazine cover artist Arthur Radebaugh dazzled millions with his imaginative visions of automotive transportation. From 1958 to 1962 in the comic strip, “Closer Than We Think!” Radebaugh depicted sci-fi-slick sedans and convertibles like the Flapwing Car, Sunray Sedan, and Quick-Change Color Car. Some of his designs have crossed the reality threshold, like electric car and self-driving car. But for the most part, his cars and other inventions never quite came to fruition despite the optimistic title of the strip. But there was a seemingly far-fetched, yet already prototyped idea that showed promise: a wheelless air car that he dubbed the Flying Carpet Car.
In July 1959, Popular Science senior editor Martin Mann was so enthralled by air cars, or Air Cushion Vehicles (ACV), that he proclaimed, “they threaten to turn transportation inside-out, giving you a sports car, speedboat, half-ton truck and back-pack helicopter all rolled into one.” At the time, Ford Motor Company had just showcased a levitating vehicle prototype, the Ford Levacar Mach I. Ford vice president Andrew Kucher promoted the model, which featured a wheelless car propelled on a cushion of air. In 1961, Popular Science followed up with another story about the future of family cars penned by an air-car inventor, William Bertelsen. The story showcased a colorfully illustrated air car dubbed the Aeromobile, a type of ground-effect machine—or GEM—that rocketed through airtight tubes. Bertelsen was just one of many inventors chasing the hovercraft dream. British inventor Christopher Cockerell, whose 1952 patent earned him recognition as the hovercraft inventor, was behind the Saunders-Roe vessel that made its 1959 debut, gliding across the English Channel on a cushion of air.
Chris Fitzgerald remembers being fascinated by the Saunders-Roe vessel when it debuted in 1959, the first such commercial ACV journey. “I was in Australia, watching with my family on TV,” recalls Fitzgerald, now president of Neoteric Hovercraft. “I was always interested in flying.” But Fitzgerald had a lot of friends who became cadets and were killed while flying. A hovercraft could be a way of flying “with one foot on the ground,” he says. That’s how he ended up founding Neoteric Hovercraft in 1960 in Australia, which manufactured one of the first personal-sized hovercraft, Neova One. Alongside Ford’s Levacar, Bertelsen’s Aeromobile, and Fitzgerald’s Neova One, the market was cluttered with new entrants, many based in the UK, including Air Bearings, Curtiss-Wright, Cushion Flight, Bartlett’s Flying Saucer, and one of the first American ACVs, Crowley’s Hydro-Air. The future of hovercrafts seemed certain.
“There were a lot of different small companies trying to make hovercraft,” says Fitzgerald, who relocated the company to Indiana in 1976 to tap the US market. “But most of them failed—for lots of reasons.”
[Related: What it would take for cars to actually fly]
Traditional aircraft get their lift from Bernoulli’s principle: the faster a fluid—in this case like air—moves, the more its pressure drops. The pressure difference between pockets of air above and below a plane’s wing or a helicopter or drone’s rotor is what enables lift and flight. Hovercraft, or air-cushion vehicles, are different from traditional aircraft because they get their lift from the pressure of air against a surface—an aerodynamic phenomenon known as ground effect. This allows ACVs to glide fractions of inches to several feet off the ground.
Flying machines based on the ground-effect principle can be traced as far back as 1716 when Swedish scientist Emanuel Swedenborg sketched out one of the earliest known designs. In the late 19th and early 20th centuries, nautical engineers sought ways to use ground effect to reduce the drag on boat hulls in water by pumping pockets of air beneath them for lift—giving the impression that it’s floating higher in the water.. But it was the pressure from World War I and II that motivated militaries in the US and Europe to pursue high-speed, water-to-land hovercraft that could rapidly move seabound troops, equipment, and supplies on shore. This helped jump start an experimental market for marine hovercraft as early as the 1930s—the technology eventually moving onto land and the automobile industry.
Despite the fevered pitch of innovation in the 1950s and ’60s, ACV technology presented obstacles that, to this day, have never been solved. In 2008, PopSci caught up with Bertelsen who was still seeking investors and working out the kinks in his ACV nearly a half-century after the national debut of the GEM. Bertelsen claimed that his ACV was far more fuel efficient than a car and blamed “last century’s low fuel prices” for lack of interest, but that claim has been difficult to base on fact. Some ACVs burn similar amounts of gas per hour of use while carrying similar loads as cars. Others burn far more.
According to Fitzgerald, ACVs “consume a fair amount of fuel.” He argues, however, that it’s unfair to compare ACVs with cars. “When an automobile runs down the road,” he explains, “it’s running on a million-dollar a mile track, which makes its fuel efficiency much better.” By design, ACVs traverse roadless and otherwise impassable terrain. When it comes to military hovercraft, Fitzgerald admits they are considerably less fuel efficient than their boat or truck counterparts. “There’s no point talking about efficiency when you’ve got to get a damn tank on the beach.” The same high operating-cost trend applied to commercial ferries: For instance, the hovercraft service that had traversed the English Channel since 1959 ceased operation in 2000.
How to keep the air cushion beneath the vehicle as it moves around has been a chief design challenge for ACVs, hindering both fuel efficiency and stability. Both flexible and rigid skirts have been used, which are supposed to keep the air trapped beneath the vehicle. But the skirts tend to wear rapidly. “So much of the technology is in the skirt,” says Fitzgerald. “It’s a compromise between how much air you’re going to pump through the hovercraft to lift it, and how much you want to sacrifice the skirt.” The more air, the more lift, which eases wear-and-tear on the skirt but requires more fuel. Plus, there’s a limit to how far you can lift an ACV before it becomes unstable. According to Fitzgerald, “that’s roughly one tenth the vehicle’s width.”
Then there’s the matter of steering. For those who had envisioned wheelless cars speeding down streets, it turns out that ACVs are challenging to maneuver and easily influenced by pressure changes caused by wind, weather, and passing vehicles. A highway filled with ACVs would be more like a game of bumper cars. Current highways are not optimally designed for such floating craft, says Fitzgerald. Their surfaces are rounded to facilitate water runoff, “but [for ACVs] they should be concave.” Many ideas have been proposed to try to control an ACV in a crowded roadway environment, Fitzgerald says. “All the obvious ones,” he notes, “like putting [small steering] wheels on it. But if you put wheels on it, you figure out pretty quickly that the best thing to do is throw the hovercraft away and just stick with [cars].”
In the late 1960s, ACV designers also suggested tracked versions to fix steering problems, similar to the version Radebaugh depicted in his Flying Carpet Car. The most notable tracked ACV project was France’s Aérotrain, which intended to replace France’s aging railway network. But after miles of elevated concrete track had been built through the countryside north of Orléans, the project was abandoned in the mid 1970s. Technical problems with maintaining pressurization and noise concerns from the big fans—coupled with politics—doomed the high-profile project. Around the same time, the British tried their own version, called Tracked Hovercraft, that promised to shuttle passengers 330 miles from London to Edinburgh—reducing a more than six hour car ride to less than 90 minutes. Technical difficulties and excessive costs put a stop to the project in 1973. In the late 1960s, Grumman, an engineering company, explored a similar tracked ACV project for the US Department of Transportation, but the project never gained approval.
Despite many ill-fated projects, ACV tech does actually exist today—finding success in less public-facing transportation. The market can be divided into what Fitzgerald calls “heavy industry” and “light industry.” Heavy industry is dominated by military use, primarily for amphibious troop movement and logistics. ACVs have also found a home in manufacturing and warehouses to move ultra-heavy loads. Plus, a few passenger hovercraft ferries remain in service, although most have been replaced with catamaran-style fast ferries, which cost less to operate.
Light industry includes local emergency services that rely on specialized hovercraft, like Neoteric’s Rescue models or Griffon Hoverwork’s Search and Rescue ACV, for rescue missions in places where terrain is challenging. Plus, there’s the recreational market for individuals.
After more than six decades, Fitzgerald remains optimistic about the future ACV market. “If you look at the total transportation system that we have,” he notes, “there’s a little spot in there where nothing works very well—thin ice, mud, fast flowing water, and shallow water.” ACVs could take off in these types of environments. Marshy areas, places where terrain is unstable, land that is prone to flooding, and regions that experience stretches of extreme heat, which can destabilize road surfaces could also benefit from ACVs, he says. “A hovercraft will do things in those places that nothing else will do quite as well.” Hovercrafts might also be a promising mode of transportation in a future warmer planet with more frequent natural catastrophes: The “little spot” where ACVs alone excel may grow, says Fitzgerald, even if it’s just for rescue missions.
While a handful of companies manufacture hovercraft today, Neoteric Hovercraft may be the only US-based company to have remained in business continuously since ACV’s heyday between the 1950s and 1960s. Fitzgerald says his ability to adapt to market demand, while staying true to his mission of manufacturing personal-sized hovercraft has kept his business alive. “I’ve been trying lots of different models to find out what the market wants,” he says. “Right now, our biggest market is individuals.”
There’s no need to wait if you’ve been holding out for a Radebaugh-style wheelless car that can fly like a plane, float like a boat, or drive like a car across any surface—wet, dry, marshy, or frozen. You can buy ACVs out on the market that cost roughly the same as a car. But you’ll still want to save city or highway driving for a gas-powered or electric car.