 On 25 May , Johnson experienced an unusual mission . His section engaged a Dornier Do 217 carrying British markings , four miles west of his base . Johnson allowed the three inexperienced pilots to attack it , but they only managed to damage the bomber . Days later , on 26 June 1942 , Johnson was awarded the Bar to his DFC . More welcome news was received late in the month as the first Spitfire Mk . IXs began reaching RAF units . On 10 July 1942 , Johnson was promoted to the rank of squadron leader , effective as of the 13 July , and given command of 610 Squadron . 
