 The last major delivery of Soviet aircraft to the Libyan Arab Jamahiriya was six Su-24 Fencers in March/April 1989.The Libyan armed forces' air doctrine of the 1990s and 2000s appeared to be of an "ad hoc" nature, and contracted personnel from Yugoslavia, South Africa, Russia, North Korea and Pakistan provided piloting, maintenance and technical services.The 1990s' drop in oil prices and a UN embargo made purchase of modern equipment almost impossible.