Compact, highly efficient heavy-fuel engines could unlock greater potential in small unmanned aircraft, enabling longer missions with heavier payloads. They also could accelerate the emerging electric ...

A company that makes an innovative rotary internal combustion engine just received a Phase I research grant from the U.S. Army to develop hybrid-electric propulsion for UAVs. The development ...

There's been a lot of development activity around flying vehicles recently, but the Air Force wants a shortcut to an unmanned electric vertical takeoff and landing (eVTOL) concept for urban transport.