After the Portuguese administration left Angola in 1975, the country has suffered from civil war. Not much is known about the structure of the Air Force of Angola. The main operational base of the Air Force is Catumbela, near Benguela. The Air Force received many aircraft from the former Soviet Union. In 1991 six C212 were purchased from CASA. The UNITA rebels claim to have destroyed over 150 aircraft since 1985. In 1999, eight Su-27's were delivered to Benguela-Catumbela, with seven on order. In 2000 twelve ex-Slovakian Su-22M4 Fitters were purchased. The Air Force uses also PC-7's, Islanders, PC-6's and a variety of helicopters.