 He then worked in the family firm of Fred Ambler Limited in Bradford, Yorkshire and during his time with the company he invented a method which increased the speed at which worsted yarn might be produced.In 1931 Ambler joined the Auxiliary Air Force and served as a pilot in No.608 Squadron (North Riding) Squadron in his spare time and in the ranks of pilot officer (7 February 1931), flying officer (7 August 1932) and flight lieutenant (25 November 1933).