Same. I studied aerospace engineering and know that small-scale jetpack flight is possible to do, and yet I cannot help but scan for weird lighting changes or lens incongruities whenever I see a video. It's so insane to see these things.

How does this not burn his legs off?

Bypass ratio and entrainment. Most of the air coming through is cool, so the overall air is merely hot, rather than “melts your legs”.

Would love if someone could answer this or knows of a video that explains jetpacks well

His titanium legs are the real story here

From another viewpoint: people fly turbine-powered model aircraft all the time. Why wouldn't you believe it?

Well for one, where is the fuel? Seems like it would take a tremendous amount of fuel and there are no visible fuel tanks on the jetpack.

They only have a flight time of about two minutes. It appears longer because they stitch together clips strategically.

Edit: It appears that I confused Vince Reffet with another "jetpack guy" - Richard Browning. The number was for Browning's device. But although you could get more airtime by adding wings, the overall point still stands - the flights are relatively short.

It's probably in the wing/back thing.

That depends on how long you want to fly for.

Inside the wing is logical, it's pretty thick and planes have it there as well.

They glide for most of the flight.

Those turbine-powered models aren't carrying 100+ kg of payload?

These rc model turbines pull 20+ kg thrust. In the video he uses turbines noticeably larger, in 50-60kg class. Granted such small turbines have low efficiency - low compression - so they burn 0.2kg fuel per 10 kg thrust per minute. Thus 4kg per minute for 200kg total weight of which fuel is 60kg at best, thus 15 minutes hover at best.

Once it becomes more popular we'll get turbofans, and that will improve the efficiency.

That lines up pretty well with the demonstrated performance of these setups, I think they all have ~15min flying time.

Can't wait for the turbofan versions! :D

How heavy of a battery would you need to power these with enough electricity to lift an adult human, think like a drone on steroids...

Lift for how long?

https://www.tmotoruavdrone.com/product-detail/48968207323300...

Looks like the motor you need. 25KW

And you'd need four of those, I'd guess... so 100kW or so.

with 57inch props - large beasts though so it would be a personal helicopter style suit (https://en.wikipedia.org/wiki/Martin_Jetpack) not true jetpack - it makes 94kg thrust at 23kw, so 2 of them is enough with 60kg/7kwh battery making for 9 minutes of hover (though full discharge is truly bad for the batteries).

Think its this one pretty much

>Thrust 395 Newton ( 39,5 Kg) http://modelaircraftcompany.com/newshop/en/home/89-jetcat-p4...

four of them so about 158 kg thrust total? It's impressive how well they work for what seems quite a simple and relatively inexpensive device.