NASA has flown its tilt-rotor hybrid electric concept aircraft and hopes it will result in a practical VTOL unmanned aircraft. Greased Lightning flew for the first time Aug. 19 (tethered) and it represents a new take on an old design first pioneered by Canadair in the 1950s and used by the V-22 Osprey. The wings and tail surfaces swivel, allowing the engines to be turned into lifting rotors. In Greased Lightning's application, however, most of the engines are shut down for cruise flight and the rotors/props fold to reduce drag.
This is a companion discussion topic for the original entry at https://www.avweb.com/recent-updates/business-military/nasa-flies-hybrid-electric-vtol