Upon leaving Felsted, Frank studied at University of Nottingham. He never completed his degree as in 1913, he left university to learn how to fly at Bristol Flying School, later becoming a flying instructor for the college.
On the outbreak of WW1 Frank joined the Royal Flying Corps and was twice mentioned in dispatches. Frank became Chairman and Technical Director at De Havilland Engine Company was responsible for the design of numerous engines including the famous Gipsy and Napier Rapier. In 1945, Frank designed the de Havilland Ghost jet engine fitted to the de Havilland Comet, the first jet air-liner.