How a jetpack design helped create a flying motorbike

Around the age of 12, David Mayman tried to build a helicopter out of fence posts and an old lawn mower.

Needless to say, it didn’t go well. His contraption didn’t fly and they forced him to fix the fence.

“I was brought up in a way that I guess challenged me scientifically… I was always told that nothing is impossible,” he says.

He may have gotten a little ahead of himself during his childhood in Sydney, but as an adult, Mr. Mayman has built innovative machines that actually fly.

After selling his online listing business, Mayman developed a jetpack, which in 2015 flew around the Statue of Liberty.

But, since 2018, he has been working on a different type of project, one that he believes will have more business opportunities.

Called Speeder, his new machine will be like a flying motorcycle. It will take off vertically, fly at high speeds, but be compact enough to fit in the back of a pickup truck.

Speeder is just one of many flying machine projects underway right now.

Hundreds of EVTOL (Electric Vertical Takeoff and Landing) aircraft are currently in development, with engineers hoping to create a new era of cheap and quiet air travel.

But Mr. Mayman’s machine is very different from those planes. Instead of running on batteries and electric motors, his Speeder uses four small jet engines, which run on aviation fuel.

That might seem like a step back in technology, but for the customers Mayman has in mind, only liquid fuel will do.

He says the military, emergency services and the offshore energy industry want a fast, compact aircraft that can carry significant weight.

For that, you need jet fuel, as it stores 20 times the energy of batteries for a given weight. Or put another way, to supply the necessary energy, the batteries would be too heavy.

“If you want to carry a certain payload and you want the aircraft to have a certain range and a certain speed, the only way to do it with current technology is with turbine engines.” explains Mr. Mayman.

The idea for the Speeder grew out of work with the US Navy, which was interested in a jetpack for use by the Navy’s special forces, the Seals.

“As is often the case in aviation, you start with one set of specs and pretty quickly end up with a completely different set of specs,” he explains.

“Initially they wanted something that would carry a payload of 210 pounds (95 kg), not too far from the project that morphed into almost 300 pounds (135 kg). And they wanted it to be possible to literally train someone in 10 minutes,” Mayman said. . he says.

None of that was possible with their existing jetpack product – something bigger and easier to fly would be needed, and so the Speeder project was born.

Some of the jetpack technology was useful in the new project, but much of it had to be developed from scratch.

To keep things simple, while in the jetpack the direction of thrust is mechanically controlled by the pilot, in the Speeder the angle of the four jet engines is controlled by an electronic flight control system.

The key part of that system is custom software that understands the physics of the four very powerful jets. This means that when the pilot takes off or turns, the Speeder can angle its jets to make that happen.

Mayman says owners won’t necessarily need a pilot’s license, since the Speeder’s flight control systems are doing much of the work to keep the aircraft stable.

“It’s effectively AI (artificial intelligence), if you want to call it that, that understands what the vehicle is going to need…so it can start signaling the engines to rev up or shut down,” says Mr. Mayman.

It’s that aspect of artificial intelligence that interests Sajal Kissoon, a research assistant in gas turbine technology at Cranfield University’s aerospace centre.

“The important enabler for this [the Speeder] is the use of AI to help control. This in itself is a very exciting development,” he explains.

“What if the Speeder faces unusual weather conditions, or unusual wind conditions, or an unusual maneuver by the pilot? I think AI would be essential to help control,” adds Ms Kissoon.

More business technology:

Mayman is hopeful that the Speeder will eventually be used to transport cargo. Piloted remotely, or autonomously, he believes there will be particular demand from the armed forces or the emergency services.

With a top speed of around 150 mph and a flight time of 30 minutes, Mayman says it could get essential supplies for the military or emergency services very quickly to where they need to be.

Being compact and capable of flying in all kinds of weather conditions, he believes it has the potential to be more versatile than a helicopter.

But before he gets too excited about the prospect of ditching the bus and hopping into a Speeder to work, Mayman says it’s unlikely he’ll be flying through cities.

“We’re loud, we’re incredibly powerful, we’re incredibly small. I don’t think there’s necessarily a need within the urban air mobility space for an aircraft that can be the size of your kitchen table.”

Crucially, much more testing still needs to be done before the Speeder is delivered to any customer. A third full-size prototype (called P2) is being prepared to fly at a test range about two hours east of Los Angeles.

There will be enough space there for the Speeder to put itself through its paces.

A key phase will also come at the end of next year, when the company hopes to start the certification process. The company estimates that it will take 12 months.

If all goes according to plan, the Speeder could be available for sale in late 2024 or 2025, though the military could start flying it sooner, according to Mayman.

Unsurprisingly, all of his engineers want to be the first to fly the machine in the desert, but Mr. Mayman keeps that excitement to himself.

“It’s pretty much the main reason they work here. So I have a long line of people waiting to try this thing out. But I’ll be pulling my range,” he says.

And hopefully for Mr. Mayman, he won’t have to fix any fences this time.