Hadn't thought of that, but the blades are going to be slapping the wake of the upstream blade 3-4 times per revolution. The helical blade style probably help

Hadn't thought of that, but the blades are going to be slapping the wake of the upstream blade 3-4 times per revolution. The helical blade style probably help with that quite a bit though. It'd be easier to sort out with all of the videos uploaded to YouTube if humans were capable of not adding cheesy soundtracks to everything.