Onslow Thompson served with the RAF/RNZAF during WW2, receiving his initial training in New Zealand, having enlisted at Initial Training Wing Levin on 2 July 1940 as Airman Pilot under training. Thompson was serving as Pilot Officer with 107 Squadron when he was awarded the DFM ion April 1942. His citation read: "This airman has completed 43 sorties. During these operations he has attacked a variety of targets, obtaining hits on warehouses at Catanzaro, destroying a number of lorries on attack on Soveranto. He took part in a second attack on a 10,000 ton enemy merchant ship which resulted in its complete abandonment. On another occasion he attacked a heavily laden merchant vessel off Tripoli : the vessel subsequently sank. This airman has shown able leadership and great determination in pressing home his attacks."

Onslow was subsequently killed in action on 1 May 1943 while flying with 105 Squadron, Bomber Command. Cause of death: air crash, due to engine failure on a Mosquito BIV DK338/0. He is buried at Marham Royal Air Force Cemetery, Norfolk, (Memorial Name: Cross of Sacrifice).

Details of final flight from "For Your Tomorrow", Vol. 2:

"Sat 1/Sun 2 May 1943 : BOMBER COMMAND : Raid on Philips factory at Eindhoven, Netherlands (by six Mosquitos - one lost).

105 Squadron, RAF (Marham, Norfolk, 2 Group)

Mosquito BIV DK338/0 - took off at 1407 but almost immediately suffered failure of the starboard engine. Unfortunately, the port propeller was feathered in error, causing the bomber to stall and crash 1/4 mile SW of the airfield. Both crew died, the pilot being buried at Marham. It was found that the engine had cut because the main fuel cock had not been fully turned on. Shortly after the accident the raid was abandoned because of cloud cover over the target.

Pilot: NZ401791 Fg Off Onslow Waldo THOMPSON, DFM, RNZAF Age 26, 932 hours solo.

Thompson's total number of ops is unknown, but by April 1942 he had completed at least 43. While serving in the M3edioterranean theatre, most or all of them with the Malta-based detachment of 107 Squadron, RAF. His brother Forrest Harold Thompson, died on 21 March 1945 while flying with 161 Squadron, RAF"

His brother Forrest Thompson also received the DFM while serving with the RAF/RNZAF during WW2. He was also killed in action when flying as Air Gunner with 161 Squadron, Fighter Command, which was attacked flying over Belgium in 1945.