Bell Textron’s X-Plane, part of DARPA’s Speed and Runway Independent Technologies (SPRINT) program, combines the straight up and down maneuverability of a helicopter with the speed of a jet. Taking cues from the Valor-280’s tiltrotor design, the X-Plane has a new trick called High-Speed Vertical Takeoff and Landing (HSVTOL). It can rise vertically, hover steady as a rock, and then zip through the air at 400 to 450 knots—about 460 to 518 mph. That’s faster than any helicopter, beating the Airbus X3’s 293 mph record and close to a commercial jet. Unlike jets, this plane doesn’t need a runway. It