Air Force has L-39 advanced training aircraft in store. The Azerbaijan Border Guard and Voluntary Society of Defense, Patriotism and Sport have Yakovlev light training aircraft. Azerbaijan has missile and radar systems intended to defend Azerbaijani airspace. There are at least 2 divisions of S-300PMU2. Thereby the country has one of the most capable SAM surface-to-air missile system in the region. Azerbaijan also operates two S-200 (SA-5 GAMMON) batteries near Baku and Mingachevir; the S-300PMU-2 represents a logical replacement for these systems offering coverage of the majority of the nation. The country also has about 100 NATO designated SA-2 Guideline (original name S-75), SA-3 Goa (S-125 Pechora-2M), and the SA-5 Gammon (S-200) are in static installations. These may be around Baku and the central part to cover the whole Azerbaijani aerospace. However, August 2011 investigations shows that after purchase of S-300 surface-to-air missiles, the largest apparent gap in Azerbaijan's air defense system may have been filled. Also in Azerbaijan there was a former Soviet early warning radar. The Gabala Radar Station was a bistatic phased-array installation, operated by the Russian Space Forces. The contract was signed in 2002 and was due to expire in 2012 where it was to be given back to the Azerbaijani government. The contract costed Russia $7 million per year. The radar station had a range of up to , and was designed to detect intercontinental ballistic missile launches as far as from the Indian Ocean. In December 2012 Russia announced that negotiations had been unsuccessful and that they had stopped using the radar station. The site was given back to Azerbaijan and all the equipment dismantled and transported to Russia. Nowadays, Russia covers the area from the Armavir Radar Station. Navy The main naval base of the Soviet Union in the Caspian Sea was based in Baku. When the Soviet Union collapsed, Azerbaijan inherited the naval base and parts of the Caspian Sea Flotilla. The Azerbaijan Navy has about 2,200 personnel. In 2010, the navy had a Petya class light frigate, Qusar (G 121), and a number of patrol craft, including one Turk class, Araz, P 223, one Brya (Project 722) class, P 218, one Shelon (Project 1388M) class, P 212, one Poluchat class (Project 368), P 219, one Luga class (Project 888), T 710, and four Petrushka (Polish UK-3 class), P 213, P 214, P 215, and P 216. There are four minesweepers consisting