In April 1915, White was appointed a captain in the Australian Imperial Force and adjutant of the Mesopotamian Half Flight, the first AFC unit to see active service. Based initially in Basra on the Shatt-el-Arab waterway and operating primitive Maurice Farman biplanes, the Half Flight assisted the Indian Army during the Mesopotamian campaign, conducting reconnaissance and sabotage missions against Turkish forces. The Farmans' top speed was only , while the desert wind could reach meaning the aircraft often made no headway or were simply blown backwards.