Alfred David Dunstan was born in Sebastapol and was a Grocer's assistant by trade when he enlisted in the August 1917 Reinforcements on 3 October 1916 at the age of 25. His unit embarked from Melbourne, Victoria, on board HMAT A60 Aeneas on 30 October 1917. . He joined the Australian Flying Corps as an air mechanic, and embarked from Melbourne on the Aeneas on October 30th 1917. He was based in England, and in July 1918 he was attached to the No. 1 Wireless School at Farnborough. After the war, while awaiting his return to Australia, he was granted leave to undertake non-military employment and undertook a course in Magnets and Automatic Telephony. He returned to Australia in February 1920, disembarking from the Cape Verde.

His brother, Sapper William Alexander Dunstan (Tree No 713) also served
Tree No 3457