The SFV-194 is a VTOL fighter with two rotary nacelles. Each nacelle have one rotor (looks like to V-22 Osprey). After vertical take-off, and transition to horizontal flight mode, three rotor's blades folding to reduce drag. Rotors powered by turboshaft engines, or directly from main engine (looks like to powering method of F-35 lifting fan)
Very elegant form of raise vertically a supersonic fighter. I found it feasible the idea of mechanically link the rotors to the main engine, and the elegant form of folding the blades to reduce drag.