 Johnson attended the University of Nottingham , where he qualified as a civil engineer , aged 22 . Johnson became a surveyor at Melton Mowbray Urban District Council before progressing to assistant engineer with Chigwell Urban District Council at Loughton . In 1938 , Johnson broke his collarbone playing rugby for Chingford Rugby Club ; the injury was wrongly set and did not heal properly , which later caused him difficulty at the start of his flying career . 
