A tilt-rotor compound VTOL aircraft has a multiple-flow thrust generator(s) comprising a gas-powered tip-jet driven rotor(s) having a thrust-augmentation ratio of at least two; that tilts about the aircraft's pitch axis wherein the rotor's plane of rotation is substantially horizontal for VTOL operations and the rotor's plane of rotation is substantially vertical forward flight operations. A relatively small fixed-wing sustains the aircraft during forward flight. Compressed exhaust gas from the fan-jet engine(s) is ducted to a manifold having valves which control power to the multiple-flow thrust generator(s) and to the jet exhaust nozzle(s) as supplemental thrust for forward propulsion and yaw control. The manifold also serves to distribute compressed gas to the dead engine side of the aircraft in the event of a dead engine emergency, and to reaction jets for attitude control during VTOL operations. Thus this tilt-rotor aircraft is more efficient, faster, immensely lighter, less complex and less expensive to purchase and maintain than its shaft-driven counterparts.