That's ingenious. It's one of those rare mechanisms that are hard to come up with but obvious once you learn of them. I recommend everyone to watch this video.

That's ingenious. It's one of those rare mechanisms that are hard to come up with but obvious once you learn of them. I recommend everyone to watch this video. (The presentation spends a lot of time explaining tail rotors, which this invention does not need. Skip to about halfway to see how it works.)