How a jetpack design helped create a flying motorbike

At 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 did not go well. His contraption didn't fly and he was made to fix the fence.

"I was brought up in a way that I guess challenged me scientifically... I was always told that nothing's impossible," he says.

Perhaps he got a bit ahead of himself during his childhood in Sydney, but as an adult Mr Mayman, has built innovative machines that really do fly.

After selling his online listings business Mr Mayman developed a jetpack, which in 2015 he flew around the Statue of Liberty

But, since 2018, he has been working on a different kind of project, one he thinks will have more commercial opportunities.

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

Speeder is just one of many flying machine projects under way at the moment.

There are currently hundreds of EVTOL (electric vertical take-off and landing) aircraft in development, with engineers hoping to create a new era of cheap, quiet air transportation.

But Mr Mayman's machine is very different from those aircraft. Instead of being powered by batteries and electric engines, his Speeder uses four small jet engines, which run on aviation fuel.

That might seem like a step backwards in technology, but for the customers Mr 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 a significant weight.

For that, you need jet fuel, as it stores 20 times the energy of batteries for a given weight. Or in other words, to supply the power needed, batteries would be too heavy.

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