The Bell-Boeing V-22 is a tiltrotor transformable aircraft introduced in 2005, capable of vertical takeoff and landing (VTOL). This type of aircraft combines the characteristics of a helicopter (hovering flight) with those of a conventional fixed-wing airplane (greater range and speed). For horizontal flight, the three rotor blades of the two transverse rotors located at the wingtips and the associated engines are tilted 90° forward. It can also be used like a STOL aircraft on very short runways. Disadvantages of this type of aircraft compared to a helicopter include high acquisition costs, high fuel consumption, and noise emissions. The Bell-Boeing V-22 was the only successfully deployed model until 2017.