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Comment by oliwary | Hacker News Reader

Cool, similar to helicopters which can also control direction indepentendent of thrust, which leads to RC helicopters being able to pull of crazy, physics-defying moves like here: https://www.youtube.com/watch?v=QSiwyoQldfo

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That's the worst lawnmower I've ever seen. It didn't even cut the grass as much as it just bothered the blades of grass. 0 out of 5 stars. What's that? It's not a mower. Oh, well then, that thing is cool as hell, but not as cool as the pilot that looks like he's just casually standing there.

is mowing grass with a helicopter an actual commononly attempted trick like a kickflip with a skateboard?

This made me chuckle:)

That is bizarre and amazing. I have never seen any kind of aircraft that resembled a dragonfly as much as that.

The maneuvers are so extreme and come so fast that I would not have been able to say for certain that this wasn't just a very nasty crash in progress. But they were, in fact, completely controlled and intentional.

Incredible.

Thank you for that. That was the most astonishing display of precision (in any field of endeavour) that I have seen in quite some time.

Thanks! I’ll keep this on hand for next time I hear that a UFO proof video comes out saying that an object can’t move the way it does on screen.

Wing area (roughly) scales by n² and mass by n³, so size matters for this kind of thing.

See https://en.wikipedia.org/wiki/On_Being_the_Right_Size (PDF at https://www.phys.ufl.edu/courses/phy3221/spring10/HaldaneRig...)

Acro RC helis are an amazing sight, but it’s not really related to the article. They’re just rotors that can reverse their thrust entirely by changing the pitch angle below zero (i.e. lower than regular helicopters can). Many prop planes use that for braking

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