What type of rotor system did it have? Youtuber Peter Sripol has a video where he designed a rubber band powered helicopter with a working tail rotor to show the mechanics of how a helicopter works. In the video he shows and explains why a stability mechanism is important and at 2:56 in the video he says that you see all these people on YouTube making their own helicopters that don't know anything about helicopters building rigid rotors system and that he is glad the helicopters are underpowered because they would just end up killing the people around them.

Here is the video its worth a watch from the start

https://www.youtube.com/watch?v=HUFMMTsmsUE