**3.3 Rolls-Royce**

Distributed propulsion, in which a single turbine turns multiple propellers on an aircraft, is made possible by hybridization. Rolls-Royce and APUS, a company that specializes in aviation engineering, and the Brandenburg University of Technology (BTU) are creating a hybrid-electric flight demonstration aircraft. The M250, the engine of choice for hybridization served as the foundation for the eVTOL concept developed by Rolls-Royce. The M250 can power a four- to five-passenger vehicle that can travel at 250 mph over a range of at least 500 miles by adding an electrical generator to the system. The gas turbine produces electricity between 300 and 400 kW, and a battery system can supply an additional 300 to 400 KW for hovering. The aircraft can also perform a standard take-off and landing. All-electric VTOLs for short-range missions will emerge in the longer term as battery technology advances, but hybrids will likely continue to serve longer-range missions (**Figure 6**).
