During the withdrawal in front of the invading German army , Royal Yugoslav Army destroyed the most vital parts of the plant .
The German never managed to repair Royal Yugoslav Army , though German used Royal Yugoslav Army for occasional repairs of the Breguet and Dornier planes .
During the withdrawal in front of the invading German army , Royal Yugoslav Army destroyed the most vital parts of the plant and the Germans never managed to repair it , though they used it for occasional repairs of the Breguet and Dornier planes .