ANZAC
Soon after the outbreak of war in 1914, the Australian Flying Corps sent aircraft to assist in capturing German colonies in what is now north-east New Guinea. However, these colonies surrendered quickly, before the planes were even unpacked. The first operational flights did not occur until 27 May 1915, when the Mesopotamian Half Flight was called upon to assist the Indian Army in protecting British oil interests in what is now Iraq. (more on Wiki HERE)