In addition they also flew missions for the Special Operations Executive (SOE), dropping men and supplies into occupied Europe.

Siegert's aircraft was hit by anti-aircraft fire, then attacked by two enemy Fw 190's, one of which his rear-gunner shot down, before he evaded the other in a violent high-speed dive.

[1] Siegert was subsequently awarded the Distinguished Flying Cross on 17 November 1944, "in recognition of gallantry and devotion to duty in the execution of air operations".

During a recent daylight sortie his aircraft was damaged by intense anti-aircraft fire, in the face of which he completed his mission successfully.

[1][6] In late 1945 Siegert was seconded to the British Overseas Airways Corporation, flying Dakota transport aircraft to Cairo and West Africa for the next two years.

[1][2][3] In October 1953 Squadron Leader Siegert was the second pilot of the RNZAF Hastings transport aircraft that took part in the London-Christchurch air race.

[11] Siegert served as an air attaché at the New Zealand Embassy in Washington D.C. between 1954 and 1957,[2] then attended the RAF Staff College in England.

[6][12] He was served as Air Officer Commanding RNZAF Operations Group in 1969,[2] and from 1971 to 1973 was chief of staff of the ANZUK forces stationed at Singapore.

[1][2] He was then appointed Deputy Chief of Defence Staff (Policy), serving until 1976,[2] being made a Commander of the Order of the British Empire in the 1975 Queen's Birthday Honours.