By August 1942, preparations were begun for a major operation, "Jubilee", at Dieppe. The Dieppe raid took place on 19 August 1942. Johnson took off at 07:40 in Spitfire VB. EP254, DW-B. Running into around 50 Bf 109s and Fw 190s in fours, pairs and singly. In a climbing attack Johnson shot down one Fw 190 which crashed into the sea and shared in the destruction of a Bf 109F. While heading back to base, Johnson attacked an alert Fw 190 which met his attack head on. The dogfight descended from 8,000 to zero feet. Flying over Dieppe, Johnson dived towards a destroyer in the hope its fire would drive off the Fw 190, now on his tail. The move worked and Johnson landed back at RAF West Malling at 09:20. For the remainder of the year, the squadron was moved to RAF Castletown in September 1942 to protect the Royal Navy fleet at Scapa Flow.