In September 1939, at the outbreak of the
Second World War Fisken volunteered for the
Royal New Zealand Air Force (RNZAF), but was initially barred from enlisting. At the time in New Zealand, farming was a
reserved occupation as it was considered vital for the war effort. It was not until March 1940 that Fisken was able to enlist, after convincing his employer to release him for service. Following this Fisken was accepted as a pilot and after completing his flying training, gained his
'wings' as a
sergeant pilot in early 1941. However, by this time he was back in New Zealand; increasingly troubled with poor health, he had been repatriated the previous month. Fisken, who by this time held the rank of
flying officer, was formally released on medical grounds from the RNZAF in December. The investiture for his DFC was held at
Wellington the following year. ==Later life==