US Army rotorcraft to incorporate an all-composite main rotor hub. Later models were outfitted as light gunships, being equipped with various armaments, such as Stinger air-to-air missiles, a .50-calibre machine gun, podded 70mm Hydra rockets and AGM-114 Hellfire air to ground missiles. Other areas of improvement were the avionics and the cockpit; new navigation and communication systems were installed along with new and larger flight instrumentation, while all light sources were redesigned for compatibility with Night Vision Goggles (NVG). Later versions were outfitted with a glass cockpit, which retained conventional instrumentation as a fallback measure. The OH-58D introduced perhaps the most distinctive feature of the Kiowa family — the Mast Mounted Sight (MMS), which resembles a beach ball perched above the rotor system. The MMS by Ball Aerospace & Technologies has a gyro-stabilized platform containing a television system (TVS), a thermal imaging system (TIS), and a laser range finder/designator (LRF/D). These features gave the OH-58D the additional mission capability of target acquisition and laser designation in day or night, limited-visibility and adverse weather. In combination with the 1553 databus, the OH-58D being first US Army helicopter to be fielded with such equipment, target data from the sensors could be directly passed to precision-guided weapons. The MMS was developed by the McDonnell Douglas Corp. in Huntington Beach, CA. Production took place primarily at facilities in Monrovia, CA. As a result of a merger with Boeing, and a later sale of the business unit, the program is currently owned and managed by DRS Technologies, with engineering support based in Cypress, CA, and production support taking place in Melbourne, FL. On the OH-58F, the MMS was removed, its functions having been replaced by the AAS-53 Common Sensor Payload, which is mounted on the chin. One distinctive feature of operational OH-58s are the knife-like extensions above and below the cockpit which are part of the passive wire strike protection system; it protects 90% of the frontal area of the helicopter from wire strikes that can be encountered at low altitudes by directing wires to the upper or lower blades before they can entangle the rotor blade or landing skids. The OH-58 was the first helicopter to test this system, after which the system was adopted by the US Army for the OH-58 and most of their other helicopters. Various other defensive and survivability measures were incorporated, such as ballistic floor armor, a missile warning