the Siberian MD, and the 15th in the Far Eastern MD, seem to have disbanded. The 127th Machine Gun Artillery Division was transformed into a motor rifle unit following the Serdyukov reforms. As of 2022, there were 1 machine gun artillery divisions and 17 artillery brigades. The Air Defense Troops (PVO) are one of the basic weapons for the destruction of enemy air forces. They consist of surface-to-air missiles, anti-aircraft artillery and radio-technical units and subdivisions. Army Aviation, while intended for the direct support of the Ground Forces, has been under the control of the Air Forces (VVS) since 2003. However, it was planned that by 2015, Army Aviation will have been transferred back to the Ground Forces and 18 new aviation brigades will have been added. Of the around 1,000 new helicopters that have been ordered under the State Armament Programmes, 900 will be for the Army Aviation. This transfer did not take place. The Spetsnaz GRU serve under the Ground Forces in peacetime and at the same time are directly subordinated to the Main Directorate of Intelligence (GRU) and will fall under GRU operational control during wartime operations or under special circumstances. The Ground Forces currently fields 7 spetsnaz brigades of varying sizes and one spetsnaz regiment. Dispositions since 2021 As a result of the 2008 Russian military reforms, the ground forces now consist of armies subordinate to the four new military districts: Western, Southern, Central, and Eastern Military Districts. The new districts have the role of 'operational strategic commands,' which command the Ground Forces as well as the Naval Forces and part of the Air and Air Defence Forces within their areas of responsibility. Each major formation is bolded, and directs the non-bolded major subordinate formations. It is not entirely clear to which superior(s) the four operational-strategic commands will report from 1 December 2010, as they command formations from multiple services (Air Force, Ground Forces & Navy). A current detailed list of the subordinate units of the four military districts can be found in the respective articles. During 2009, all 23 remaining divisions were reorganised into four tank brigades, 35 motor-rifle brigades, one prikritiya brigade formed from a machinegun-light artillery division, and three airborne-assault brigades (pre-existing). Almost all are now designated otdelnaya (separate), with only several brigades retaining the guards honorific title. In 2013, two of these brigades were reactivated as full divisions: the 2nd Guards Tamanskaya