In 1981, using experience gained from the XV-3 and XV-15, Bell and Boeing Helicopters began developing the V-22 Osprey, a twin-turboshaft military tiltrotor aircraft for the U.S. Air Force and the U.S. Marine Corps.
Leta 1972 z financiranjem od NASE in Ameriške vojske Bell Helicopter Textron začel z razvojem XV-15, dvomotornega tiltrotor zrakoplova za raziskave koncepta in morebitno uporabo v vojaške in civilne namene.