Was a member of the Pathfinder Force with 627 (PFF) Squadron RAF.

On re-entry to the RNZAF in 1953, flew with 41 Squadron [Bristol Freighters] and 42 Squadron [Dakotas]. During 1953 - 1954 flew with the Royal Flight RNZAF for the Royal Tour. Also served with The Queens Flight RAF during a Royal Visit to Nepal in 1961.

Member of the 'Goldfish Club'. Whilst serving with the 627 Squadron, On the 27th March Flying Officer Barnett was on a Special Mine Laying operation, near Heligoland, light flak, caused the crew to belly-flop into the ocean. Flying Officer Barnett and Flight Sergeant J.A. Day of the Royal Australian Air Force spent four days in the ocean. On the fourth morning they awoke to find themselves bouncing on a rock close to a rock wall which turned out to be Hallig Hooge in the North Friesian Islands. He was then taken as a Prisoner of War in Schleswig.

"After two weeks in Hospital for treatment of his injuries from the forced-landing, Barnett was made Officer-in-Charge of the Camp which had no other officers. On May 5, the German commandmant of the camp handed over responsibility to Fg Off Barnett when he, and all his guards withdrew. After solving the food problems of the camp he was some days later, appointed by the Allied Contol Commission as officer responsible for all the territory between the Danish border and the Kiel Canal, containing some 5,000 plus SS troops, and over 500 aircraft, including many single seat FW 190s which continued to arrive from the Eastern Front with up to three pilots sharing the one seat. Fg Off Barnett continued to exercise the responsibility for this area for some weeks before being repatriated to the United Kingdom, and eventual retun to New Zealand.

Sqn Ldr Barnett returned to active flying in the RNZAF in 1953 when he flew with 41 Sqn (Bristol Freighter), including supply dropping in Malaya and Thailand; the RNZAF Transport Support Unit and 42 Sqn RNZAF. Service with the 42 Sqn included duty with the 'Queen's Flight' during the Royal Tour of New Zealand in 1953-1954. 1961 saw service with the Queen's Flight, RAF, with Flt Lt Barnett and crew giving essential support with an RNZAF Bristol Freighter aircraft during the Nepal phase of a Royal Tour to that area." Hanson, p. 74 AWMM