The dream of personal flight took a great leap forward last week as Jetpack Aviation unveiled its JB-9 jetpack in spectacular fashion. Lifting off from a boat, inventor and aviator David Mayman flew the powerful, agile JB-9 around the Statue of Liberty, pausing to salute and pirouette before touching back down. Running on kerosene and using two vectored jet engines, the JB-9 can reach high speeds and altitudes and offers a flight time over 10 minutes, depending on pilot weight. We spoke at length with Mayman to discover how the JB-9 works and how long it'll be before we can buy one.
Believe it or not, people have been trying to build a jetpack for nearly a hundred years now. A portable, powerful device you can strap to your back, fire up and take to the skies for true freedom in three dimensions.
Things must have looked very positive in the 1960s when Bell's Rocketbelt made its public debut. Thats the kind of design you might remember from the 1984 Olympics opening ceremony in Los Angeles. These hydrogen peroxide rocket belts are compact, very cool to look at, and perform more or less as you'd expect a jetpack to. Unfortunately they're also difficult to fly, the fuel is extremely pricey and it runs out so quickly that you're limited to about 30 seconds of flight.
More recently, you've got the Martin Jet Pack, which offers more than 30 minutes of flight endurance, which has safety systems built in, and which you should soon be able to actually buy for a couple of hundred grand. But it's enormous, about as portable as a piano, and you can't strap it to your back and walk anywhere.
There's Yves Rossy, the Swiss Rocketman who soars through the sky on a jet-powered wing at more than 300 km/h and performs all manner of incredible aerobatics. But that's likewise a pretty big chunk of kit, it needs to be launched at speed from a plane that's already in the air, and at the end of the day you're about as likely to get a chance to fly one yourself as you are to visit the moon.
Then there's Troy Hartman's parafoil jetpack, which was an accidental discovery in the process of trying to build a jet wing similar to Rossy's. But it needs a strong enough breeze to lift and fill the parachute in order to get going, and it just doesn't really look the part.
All of which is a long-winded way to point out that this is a really difficult problem to solve, so when you see the video of the JB-9below, you're looking at a significant achievement and a milestone in personal flight.
Jetpack Aviation is the brainchild and passion project of Australian businessman David Mayman. "I've been flying it off the public radar for some time," Mayman told us this morning. "It was time to bring it out of the closet, so to speak. I've spent my life in software and mining and fairly sensible occupations, but my overriding passion has been to build a jetpack, since I was very young. Nelson Tyler and I got together 10 years ago –he's an extraordinary engineer and inventor based in Hollywood. And that's really what's made it possible."
In Tyler, Mayman found the perfect partner. Tyler had worked on the Rocketbelt flight project at the 1984 Olympics, and for the last 45 years had been every bit as obsessed as Mayman with the idea of building a proper portable jetpack with decent endurance that anyone could fly. And the JB-9 jetpack they have just demonstrated is really the first design that meets most people's expectations of what a real jetpack should be.
"It's a jet and a backpack," says Mayman, alluding to the fact that many competitors are, well, neither. "It can take off vertically. With no fuel in it, I've jogged about a kilometer with it strapped to my back. Even full of fuel I've jogged a few hundred metres. There's a large suitcase that our whole JB-9 will fit into. It'll fit in the back of a car. The little handles fold up but that's about it."
And the total endurance for the JB-9? "10 minutes plus, depending on pilot weight," says Mayman. "For the technically minded, it also depends a little bit on temperature, altitude and that kind of thing, but that's by no means as significant as the total pilot weight."
The device can carry a total of 10 gallons of fuel, which it burns at around a gallon a minute. And the fuel itself is simple: kerosene. Cheap, safe and easily available from your local service station.
The JB-9 uses a carbon-fiber corset that straps to the pilot's back, with the majority of the "backpack" section carrying fuel. Mounted to each side is a small jet turbine engine that provides upward thrust. These engines mix ambient air with their exhaust gases to bring temperatures down to a comfortably warm airstream, but Mayman still wears a fireproof Nomex suit just in case: "The exhaust temperature actually declines really quickly. It's still warm, don't get me wrong. On a cold night it's exactly what you want running next to you, but it's not something that sets the ground on fire."
"On the left hand I've got a twistgrip controlling yaw," says Mayman. "If I turn my hand to the left, I spin to the left. You'll see some little yaw vanes at the bottom of each engine, a little cup that tilts backward and forward. They're not on servo motors, they're on push/pull cables. That's how we control yaw. They're always going in the opposite direction to each other, so if you vector the right engine forward, the left one goes backward and you get that yaw rotation.
"On the right I've got a fly by wire throttle driving the engines. That actually works back to front compared to a motorcycle throttle. Going back into the 1960s, the way Bell had it set up, you turn your hand inwards to develop thrust. Ours works the same way."
The twistgrips sit on the end of levers, which can be pushed up and down to tilt the jet engines, either individually or together, says Mayman. "This makes our device more maneuverable than anything else out there right now. Rather than just vectoring the thrust, we're vectoring the entire engine. They're on a sort of gimbal arrangement. You're not only moving the line of the thrust, you're moving the centre of thrust. What it means effectively is that I can go from a standing start, get up to a pretty high speed and stop on a dime, turn, spin, that sort of thing.
"To go forward or backwards, which requires pitch, effectively what I'm doing is pushing both handles down, that'll make me go forward. Pulling them up, or actually allowing them to come up, because that's what they want to do under thrust, that'll make me go backwards. Or more likely, just slow down from speed. The whole thing is completely manual at the moment, it's literally a pair of levers tilting the engines.
"You don't need much roll. I've got a lot of time in helicopters and it's similar to that. Once you start a roll in a helicopter using lateral cyclic, the helicopter will basically follow that, you don't need to push it. It's the same on this. It's kind of kinesthetic, once you start a roll by shifting your body one way and pushing your arms down a little to the left, it'll continue that rolling motion to the left. So it doesn't need very much but there's roll control in that sense."
The JB-9 already has some pretty fearsome capabilities. "The New York video was showing a hundredth of what this thing is capable of and what I've done, but clearly I was being a bit cautious on the day," Mayman tells us. "We've limited JB-9 to the required standards, which is 55 knots, or just over 100 kilometers per hour. JB-10, which we've already got a prototype running for and which I've already flown, will be capable of well over 200 kilometers per hour. That's horizontal speed.
"Vertical speed depends more on your fuel payload. You'd probably get an initial climb rate of 500-1000 feet a minute. As your fuel burns off, you get extraordinary vertical rates. You can go up a thousand feet a minute. Being turbine engines, they don't run out of performance as the air thins. They'll just keep going, they're compressing the air like a turbocharger. You could keep going up to 10,000 feet. But I won't be putting my hand up for that one immediately!"
Mayman says the current JB-9 design is perfectly legal to sell and fly: "Technically we could start selling them in the ultralight category tomorrow. It couldn't hold more than 5 US gallons of fuel (meaning a flight time around 5 minutes), and there's certain restrictions about where you could fly them.
"It would be pretty expensive, but there are many people in the world that have the resources to do something like that. They don't even need to have a license under the ultralight category, and there's no certification of the device itself."
So would he sell you one? "Right now, I wouldn't. We've had some people in the office writing some pretty large multi-million dollar cheques in front of us and we've said no. I want to be sensible about who's got their hands on this thing. We have certain responsibilities here and in other parts of the world with countries that are friendly to the situation I'm in at the moment – expectations that we don't go selling them willy-nilly.
"I'd wanna feel like we have an infrastructure to train them … we could technically just send them the unit in a box and say 'good luck' but it's not necessarily going to end well if you're doing 200 km/h, 5 feet off the ground, you know? It could be a monster. But we're working on it. We'll get there."
Before a JB series machine goes to market, the next step for Jetpack Aviation is to give the device a brain and the ability to stabilize itself – a goal Mayman considers well within reach. "The sensors, they're a dime a dozen. Accelerometers, solid state gyros and whatnot, every iPhone has what we need, except of course we go for the $5,000 mil-spec ones.
"What we're gonna do is build in little linear actuators so the computer can mechanically drive these arms. We're still gonna be moving the arms up and down, but it'll be driven by computer. And people can override that if they want to, it'll be kind of like a helicopter autopilot, you'll be able to push through it.
"One day we'll get to the point where you could strap it on, and push the green button, and it'll come up into a hover by itself. You won't need any training. This stuff is not massively clever any more and it's certainly not heavy. It's just a matter of time and money."
So a consumer model stabilized jetpack is definitely in the works. Depending on jurisdiction, you might not even need a basic pilot's course to fly one. And in the meanwhile, you might still get the chance to see the JB series units in action in a town near you.
"One of the things we're looking at right now with a very well known brand is putting together a little race series," says Mayman. "We'll build the packs, we'll train them properly, the series can travel from place to place and I think people would very much enjoy seeing them. It's one thing to watch it on a video, but when you're standing in front of one of these things and they launch in front of you, it's just amazing."
Amazing indeed. A properly functioning, safe, portable jetpack will have all sorts of practical applications and commercial use cases. But more importantly, they'll just be massively cool. If airplanes and helicopters are like the cars of the sky, then jetpacks will be like motorcycles, putting you in the middle of the scenery and enhancing the emotion and immersion of the experience. Sign me up.
Source: Jetpack Aviation
Note: If you want to keep track of the JB-9's progress, keep an eye on the Own the Sky Facebook page. A film team from Firelight Productions and Paper Bark Films has been following Mayman's progress for the last 10 years to produce a documentary. Should be a cracker!
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