The Canard Rotor/Wing (CRW) is a class of VTOL aircraft capable of both fixed-wing and rotary-wing flight. For vertical take-off, hovering, low-speed flight, and vertical landing, the main airfoil is spun like a helicopter's rotor by directing the exhaust from a jet engine through thrust nozzles in the wingtips. Because the rotor is driven directly by jet thrust, there is no need for a tail rotor to control torque as in a conventional helicopter. For high-speed flight, the exhaust is redirected through an ordinary jet nozzle and the airfoil is held in a fixed position, as in a conventional airplane. Boeing initially proposed using the CRW configuration to fill a requirement for a VTOL aircraft suitable for escorting the V-22 tiltrotor. The destruction of both of Boeing's X-50 CRW prototypes, however, has halted development of this technology for now.