 The authors of the Library of Congress Country Study on Zaire commented in 1992 @-@ 93 that : " The maintenance status of equipment in the inventory has traditionally varied , depending on a unit 's priority and the presence or absence of foreign advisers and technicians . A considerable portion of military equipment is not operational , primarily as a result of shortages of spare parts , poor maintenance , and theft . For example , the tanks of the 1st Armored Brigade often have a nonoperational rate approaching 70 to 80 percent . After a visit by a Chinese technical team in 1985 , most of the tanks operated , but such an improved status generally has not lasted long beyond the departure of the visiting team . Several factors complicate maintenance in Zairian units . Maintenance personnel often lack the training necessary to maintain modern military equipment . Moreover , the wide variety of military equipment and the staggering array of spare parts necessary to maintain it not only clog the logistic network but also are expensive . 
