Bell Boeing Quad TiltRotor

The Bell Boeing Quad TiltRotor (QTR) is a proposed four-rotor derivative of the Bell Boeing V-22 Osprey developed jointly by Bell Helicopter and Boeing. The concept is a contender in the U.S. Army's Joint Heavy Lift program (a part of Future Vertical Lift program).

Source: Wikipedia — Bell Boeing Quad TiltRotor (CC BY-SA 4.0)