 During Angola's long-running civil war, MiG-21s of the Cuban Air Force were frequently deployed to attack ground targets manned by rebel forces or engage South African Air Force Mirage F1s conducting cross-border strikes.Most MiG-21 losses over Angola were attributed to accurate ground fire, such as an example downed by National Union for the Total Independence of Angola (UNITA) insurgents near Luena with an American FIM-92 Stinger.Despite extensive losses to man-portable air-defense systems, MiG-21s were instrumental during the Battle of Cuito Cuanavale; Cuban pilots became accustomed to flying up to three sorties a day.