You could also do a hike&fly, which is where you hike up a mountain and then jump. From that point you just catch thermals, so literally zero fuel (except food for you body I guess)
They do use a winch that gets them up a couple hundred feet or so - it’s technically not energy-free, but it’s pretty darn close to it. It basically shortens the initial climb and makes it easier since they basically have to find a thermal to gain altitude. So having a couple hundred feet to play with means they can fly around to find a thermal.
So they could take off without the winch, but it helps. But it’s such a minimal amount of energy that while it technically means not quite energy-free, it’s pretty darn close.
And once they find that first thermal, it’s certainly energy free for as long/far as they can go, which can be hundreds of miles.
Except the fuel used to get them to altitude?
You could also do a hike&fly, which is where you hike up a mountain and then jump. From that point you just catch thermals, so literally zero fuel (except food for you body I guess)
See the video, but not really.
spoiler
A tiny bit for the initial winch, but most of the altitude gain is just air currents.
They said they use a mechanical winch in the video, so they might not use any fuel at all, even for the initial launch.
They do use a winch that gets them up a couple hundred feet or so - it’s technically not energy-free, but it’s pretty darn close to it. It basically shortens the initial climb and makes it easier since they basically have to find a thermal to gain altitude. So having a couple hundred feet to play with means they can fly around to find a thermal.
So they could take off without the winch, but it helps. But it’s such a minimal amount of energy that while it technically means not quite energy-free, it’s pretty darn close.
And once they find that first thermal, it’s certainly energy free for as long/far as they can go, which can be hundreds of miles.
Ackhually the title says they can fly 200km with no fuel, clearly they didn’t count the tens (hundred?) of meters of going up in that 200km.
Height ≠ Distance
I guess?