On 8 October 1966 during Operation Canberra in Phuoc Tuy Province South Vietnam, B Company, 5th Battalion, The Royal Australian Regiment was directed to dear the Nui Thi Vai Hill which was a large rocky, steep, densely covered feature. The area was known to be heavily bobby trapped by the Viet Cong. Private Hillier and another soldier as forward scouts located a booby trap, deloused it and a few minutes later heard voices of enemy close by. Private Hillier advised his Platoon Commander by hand signal and covered the other scout who moved forward to investigate. Initially fifteen Viet Cong were sighted. and later thirty Viet Cong. Both Private Hillier and the other scout remained in a position of observation for approximately fifty minutes; at times the enemy came within five yards of their position but the scouts were not seen. Based on the information passed back by Private Hillier and the other scout and other information it was concluded that the Viet Cong could be up to Battalion strength and B Company was ordered to withdraw four hundred metres to allow artillery and airstrikes to be made on enemy positions. Both scouts then skilfully extracted themselves without disclosing their presence to the Viet Cong and so alerting them. Artillery and airstrikes were then made on the enemy base which was later successfully destroyed. The skill, courage and determination displayed. by Private Hillier was of a very high order and enabled the area to be cleared without casualties to his platoon or Company.