Yes it is, The idea is for powering the rotor with installed, very light weight, high power engines to eliminate torque issues much like the later 'tip-jet' and 'hot-cycle' helicopters would use. The idea has been brought up multiple times. In this case since tip-jets weren't around they natural thought was to use prop dirven engines on the blades. You can probably see why this didn't work out to wellIs that a propeller driven rotor on the first image 2nd row 2nd cell???