cavelamb cavelamb earthlink.net wrote:

John Doe wrote:
cavelamb cavelamb earthlink.net wrote:

Just babbling...

Look up gyroscopic precession - torque induced.

Might also consider tip speeds, and what happens when props
contact things...

So put a cage around it. That is what the example from Australia
does.

But seriously. A sixth grader could figure out that one.

And the precession?

There are dozens of paragliding videos on YouTube using a backpack
propeller. Let me know if you see any evidence of that.