DARPA’s Shepard application will adapt IARPA’s ultraquiet ducted-lover Great Horned Owl (still left) into a stealthy hybrid-electric unmanned aircraft.

Credit: DARPA

Several X-planes have at any time led directly to an operational aircraft. Several of the technologies they pioneered have uncovered their way into manufacturing aircraft but normally immediately after a gap of lots of decades, even decades—an interregnum known as the “valley of dying.” Shepard to fly stealthy hybrid-electrical unmanned…