 During these trials, on 9 March 1939, Unwin deliberately crashed a Spitfire (K9797) following an engine failure to avoid a children's playground at Acton, Suffolk.Unwin's first combat experience came during the final phase of the French Campaign during the Battle of Dunkirk.During a nine-day period of patrols between 26 May and 4 June Unwin claimed three kills and a probable during Operation Dynamo.