He was in the New Zealand Expeditionary Force in World War I, having joined the Army as a 14 year old trumpeter.
He studied part-time at Victoria University of Wellington (VUW) for a law degree; and qualified as a lawyer.
In World War II he was a Colonel in the NZEF 16th Railway Operating Company in the Middle East; later promoted to Major.
[1] As General Manager of NZR, he advocated for Railway electrification in New Zealand, though some of his engineering staff disagreed with this emphasis.
Brett says that Aicken fell out with NZR colleagues and with the new National Government when he retired at only 57 years, although public servants in the Government Superannuation Fund (GSF) then usually had to retire after 40 years of service, and there is no indication on his file that there was any desire for an extension of service by him or the minister.