David enlisted on 12 July 1940 and embarked with 2 / 2nd Field Company Engineers, Royal Australian Engineers (R.A.E.) for the Middle East aboard HMT M.M on 10 Apr 1941. He was appointed Lance Corporal on 12 Jun 1941 and returned to Australia on 28 Mar 1942. He reverted to Sapper on 24 Jun 1942 and transferred to 2/11th Australian Army Troop Company, R.A.E. He was appointed Lance Corporal on 30 Sept 1942 and promoted Acting Corporal on 4 Dec 1942. He reverted to Private at his own request (this was needed to be accepted for commando training) on 1 Mar 1943. He transferred to 1st Australian Commando Training Battalion on 22 Mar 1943 and joined the unit at Canungra, Qld, 15 May 1943.
David was again appointed Lance Corporal on 6 Jun 1943 and embarked with the unit for New Guinea aboard S.S. “DUNTROON” on 17 Jun 1943 as a Lance Corporal in No 6 Section, “B” Troop. He was appointed Paid Lance Corporal on 1 Jul 1943. He flew to Brisbane on 7 Aug 1944 to attend Land Headquarters School, Military Engineers NCO's School Number 74. He qualified on 25 Nov 1944 and re joined the unit on 8 Feb 1945 and embarked for New Britain aboard “TAROONA” on 9 Apr 1945 with the unit as a Lance Corporal in No 6 Section, “B” Troop. He transferred out of the unit 25 Sept 1945 for return to Australia and was discharged 8 Oct 1945.
He was entitled to the 1939-45 Star, Africa Star, Pacific Star, Defence Medal, War Medal and Australian Service Medal 1939-45.