the Soviet 122mm BM-21 Grad and the Chinese PHL-81. Also reported in 2013 were Soviet M43 mortars (120mm). Anti-tank and anti-aircraft weapons reported included a number of British-made Swingfire, 54 Soviet 9K32 Strela-2 (SA-7 Grail), and a large number of various anti-aircraft guns. T-72 main battle tanks, FB-6A mobile air defense systems, 9K33 Osa mobile air defence systems, and WS1 and WS2 MRLS have also been spotted with the Sudanese armed forces. Armored vehicles are produced, maintained, and repaired at the Elshaheed Ibrahim Shams el Deen Complex in Khartoum. Air Force The Sudanese Air Force operates Mil Mi-24 attack helicopters, Karakuram K-8 training aircraft, MiG-29 fighters, and Su-25, Su-24, F-5, and Nanchang Q-5 'Fantan' fighter-attack aircraft. Soon after agreeing in November 1976 to provide Sudan with selected arms, the United States sold Sudan transport aircraft, a purchase financed by Saudi Arabia, followed several years later by F–5 combat aircraft. A long-established training centre and airbase is at Wadi Sayyidna, where No. 2 Fighter-Attack Squadron SuAF operated J-7s for a period. The Armed Forces have suffered significant numbers of senior personnel killed in several aircraft crashes, in 2001, and in August 2012. Navy A visit by Josip Broz Tito, the President of Yugoslavia, to Sudan in 1959 helped build the impetus to create the Sudanese Navy. Yugoslavia was instrumental in the founding, training, and supply of vessels for the Sudanese Navy. Yugoslavia initially provided four coastal patrol boats. It was eventually established in 1962 to operate on the Red Sea coast and the River Nile. In 1971, British Defence Intelligence said the Navy comprised six patrol craft, two landing craft, and three auxiliary vessels with its base at Port Sudan. In 1999, estimated naval strength was 1,300 officers and men. Reported bases were at Port Sudan and Flamingo Bay on the Red Sea and at Khartoum. The navy had two 70-ton, 75-foot, Kadir-class coastal patrol craft (Kadir [129] and Karari [130]), both transferred from Iran to Sudan in 1975, as well as sixteen inshore patrol craft and two supply ships: 4 Kurmuk class patrol boats 1 Swiftship type patrol boat 2 ex-Yugoslav patrol boats (Kraljevica class) 3 Sewart type patrol craft 2 Sobat class amphibious/Transport/Supply boats The navy, according to 2004 estimates from the International Institute for Strategic Studies, had 1,800 personnel, and a base at Marsa Gwayawi on the Red Sea. By 2017 IISS estimates for navy personnel had fallen