The man on the board, French inventor and jet skier Franky Zapata, has for years been divining ways for humans to release themselves from the shackles of gravity. In 2011, Zapata unveiled his Flyboard, a device that could propel its pilot as high as 9 meters (about 30 ft) into the air, using a hose connected to a jet ski to propel water through the board and two stabilizer jets on the rider’s arms. You’ve probably seen YouTube videos of many people failing spectacularly as they tried to avoid crashing.

Since then, Zapata has been trying to build a jet-powered version that doesn’t require water to power riders into the sky. For Bastille Day, he flew one of his prototypes, armed with the (presumably fake) firearm. Zapata was actually going to sell his company to Implant Sciences, a military contractor, but that deal fell through in late 2016. That didn’t stop Zapata from getting his Flyboard Air model in front of military officials.

It’s unclear whether the US military has seriously looked into Zapata’s inventions. Macron’s tweet about Zapata’s display at the event does seem to suggest that he would like to see Flyboards deployed in the French military—or that he has no idea Zapata’s machine isn’t the result of French military research.

Zapata is not the only highflier

Zapata is not the only one trying to turn science fiction into reality. In 2017, British inventor Richard Browning unveiled the Daedalus Mark 1, a jet-powered flying suit he’d been developing for the past year. Browning’s design put jets on the pilot’s forearms and back. Just about every publication on the internet quickly rushed to call his design a real-life Iron Man suit. (Earlier this year, Browning worked with celebrity special-effects creator Adam Savage to actually turn his technology into an Iron Man suit.)

Browning’s Gravity Industries now sells jet-pack flights as experiences, and a lucky few can buy custom suits of their own. The 1,050-horsepower suits reportedly cost $440,000 each. On a full tank of jet fuel, a ride can last five to 10 minutes.

Another company, JetPack Aviation, which makes a pack that looks much closer to the ones researchers toyed around with in the 1960s, is also closing in on realistic prototypes. The company reportedly will have a full-scale working prototype to show the US military’s Special Operations Command later this summer, according to Stars and Stripes. (The company wasn’t immediately available to comment.)

JetPack Aviation and a host of companies and inventors, are also working on larger machines intended to transport a single person. Boeing is even sponsoring a $1-million competition to find a viable personal flying machine design—finalists are expected to partake in a “fly-off” on Feb. 29, 2020. Google founder Larry Page is also personally financing a flying-car company.

Why isn’t anyone using jetpacks?

How come we haven’t seen any members of the military—or any bored billionaire for that matter—routinely fly around yet? There are a lot of reasons. Here are a few of the more pertinent ones:

They’re expensive. These machines—at least for the near future—are not going to be cheap. Browning’s cost nearly half a million dollars each. Zapata’s apparently used to cost $250,000, although it doesn’t appear that he has any available for sale right now. (Zapata wasn’t immediately available to comment on their availability.)

As the military blog The War Zone has pointed out, outfitting even a small nine-person infantry team with Zapata’s machine would cost around $2 million. It’s not quite the cost of a F-35 fighter jet, but it’s up there.

Not much fuel. These things aren’t going to be used for long-distance flights anytime soon. The Gravity suit can fly for less than 10 minutes, and JetPack’s can apparently fly for just a little bit longer. If your flight time under ideal circumstances is only 10 minutes, you’re probably going to only be flying about 4 to 5 minutes from where you started—if you want to get back.

A man flying a water jet pack
A somewhat safer water-based machine.
Image: Reuters/Mike Blake

Pretty easy target. Flying any of these devices would make you a pretty easy-to-spot target for any enemy, The War Zone also pointed out. These machines are all also extremely loud, so any element of surprise you might have by descending from the air would probably be lost as your enemy hears you coming long before they see you.

You don’t seem to be able to actually fire a gun from one. It’s not clear from the Bastille Day video whether Zapata was carrying a real rifle, but it does seem like it wouldn’t be particularly easy to fire a gun while flying. Zapata is controlling the hoverboard with a device in his right hand, and had the rifle in the left. Despite what you might see in action movies, there are very few guns that can be fired with any degree of accuracy with one hand, and a rifle that size definitely isn’t one. So while you’re flying toward your enemy, who likely will be on the ground shooting at you with a decent degree of accuracy, you’ll be trying to fly toward them without crashing—or shooting yourself.

They’re very difficult to master. Browning, before even starting on the Daedalus, was a triathlete and ultra-marathoner. He’s said that it takes an immense amount of arm and core strength to stabilize your body against the thrust of the jets. While many troops might be have the level of fitness needed to control one of these machines, the demands are probably not what the average person would want to deal with on their commute. Zapata’s site reminds people that his Flyboard Air is not available for recreational use. And if it ever were, it would require 100 hours of training on the (somewhat safer) water version first.

They’re a in a regulatory grey area. Pretty much everything that flies in the US, from toy drones up to jumbo jets, is regulated by the Federal Aviation Administration (FAA). These jetpacks would be no different. The FAA told Quartz that it would evaluate any new types of flying products on a case-by-case basis.

It’s possible that personal flying vehicles may meet the definition of what the FAA calls an “ultralight” aircraft,  machines generally can only fly one person, that weigh under 254 pounds, and carry less than five gallons of fuel. Ultralights, the FAA said, don’t require FAA certification. 

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.