Discarding Sabot (APDS) can be used. Stated penetration for the 3UBR8 round is 25 mm of RHA at 1,500 meters. The standard missile armament of the Mi-28N is the supersonic 9M120 Ataka-V missile, which uses radio beam-riding guidance. Two racks can each carry 8 Ataka missiles, giving a total of 16 missile, although 8 Atakas is a more normal load. There are four variants of the Ataka missile for different tasks. The 9M120 Tandem High Explosive Anti-Tank (HEAT) warhead variant is used against tanks fitted with Explosive Reactive Armor (ERA), its stated penetrative ability is 800 mm Rolled Homogeneous Armour (RHA). The 9M120F thermobaric variant is used against infantry, buildings, bunkers, and caves. The 9M120O expanding rod warhead variant is used against helicopters. All the variants have a range of 6 km. The 9M120M improved version has a longer range (8 km) and better penetration (900 mm of RHA). All variants use SACLOS missile guidance. Unguided weapons such as rockets can be carried on four pylons under the stub wings. Typical rockets carried are the S-13, fired from five-round B-13 rocket pods, and the S-8, fired from 20-round B8V-20 pods. The S-8 and S-13 rockets used by the Mi-28 are usually unguided. In the most common configuration, one can expect 40 S-8 rockets or 10 S-13 rockets. Both rockets have their variants, from HEAT warheads to thermobaric warheads. The S-8 has a shorter range and smaller warhead than the S-13, but compensates with numbers. Currently, the Russian Air Force are upgrading their S-8 and S-13 rockets to laser guided missiles with the proposed Ugroza ("Menace") system. Rockets upgraded under Ugroza received the designations S-8Kor and S-13Kor, respectively. The Mi-28 can also carry the IR guided R-73 air-to-air missiles, the Kh-25 air-to-surface missiles as well as up to 500 kg aerial bombs. Operational history Russia The first production examples of the Mi-28N completed factory flight and armament tests in late May 2006, and were received by the Russian Air Force on 5 June 2006. The Mi-28N was officially accepted three years later, in October 2009. It was assumed the Mi-28N would fully replace the older Mi-24 variant in the Russian Armed Forces by 2015. In September 2011, six Mi-28Ns of the Russian Air Force took part in the 2011 Union Shield joint Russian-Belarusian military exercise at the Ashuluk training ground in Astrakhan Oblast, Russia. To improve the training of pilots for