Its amazing that someone thought that would be a good idea.

http://1000aircraftphotos.com/Helicopters/999.htm

Would you fly this one?


Definitely!
The reason, why somebody tried this very good, but unusual (and at first
confusing) concept is:

As we all know, a helicopter is at least statically unstable. This is
one of the big disadvantages esp. in hovering.

BUT, if the CG is above the rotor disc, the whole things becomes
stable!!!