The OH-58 is the military version of the Bell® 206 Jet Ranger. The first of these machines were delivered to the US Army as early as 1969. Numerous improvements have led to the OH-58D version that was first delivered in 1985. The helicopter was a four-bladed main-rotor, a more powerful engine and advanced navigation and communication systems that are recognisable by the eye-catching spherical block above the main-rotor head.