On
Bastille Day, 14 July, the task force took to the road, and two days later at dusk, the various units had reached
Ea H'leo. The French having learned some of the lessons from Mang Yang Pass had prepared themselves in case of another ambush - the artillery were pushed up to support the front units, while infantry units and vehicles established temporary defensive positions. The artillery themselves would be supported by tanks when they moved up. In addition, they would have aerial support from
B-26 bombers flying from bases in Nha Trang. On 17 July the GM.42 column was passing through areas of potential ambush sites, but nothing was seen, and no attacks took place. As they approached the dangerous Chu Dreh Pass, the Montagnard infantry slowly got through without trouble, while I/Corée and the artillery formed the rearguard. At 10:50, they had left the southern end of the pass when the 8th Montagnard battalion and the Brigade HQ of I/Corée were suddenly attacked by the Viet Minh. These were local units from the 96th Regiment which opened up on the convoy with 81mm mortars, 60mm mortars, and
Recoilless rifles. The Viet Minh managed to create choke points at both the northern and southern ends of the pass. The soft skinned vehicles were targeted and soon a dozen trucks were blazing between the ends of the pass. Two companies of the 8th Montagnard battalion and the 4th company of I/Corée were destroyed within an hour. Other units around the choke points of the ambush were trying to fight their way out northwards by leap frogging, and at the same time dragging their wounded. Most of the French radios were knocked out causing chaos and confusion. It meant that on the south side of the pass, the rest of GM.42 not realising what was going on further up, were attempting to stave off an ambush there. They managed to call in air support from the B-26s, which eventually managed to help their situation. Nevertheless, the 5th (Royal Poland) Cuirassiers' tanks and vehicles meanwhile arrived at the pass not realising the plight of their cohorts and they too were hit. The Viet Minh then stormed the vehicles with infantry in the hope of capturing their guns and radio sets. Soon they were crawling over the armoured vehicles and tanks. The 'Royal Poland' despite the heavy losses they had sustained, saved I/Corée from being completely wiped out. By 14:00 the Viet Minh broke off their attack satisfied with the destruction they had inflicted. The French managed to withdraw, but it took some time for the survivors who managed to escape the ambush to arrive at Buôn Ma Thuột. All had arrived by 25 July. ==Aftermath==