Harris was pilot of N2980 during the Heligoland battle and second in command under Richard Kellett. He won his DFC that day and attributed his survival to the discipline of formation flying that he had developed with Squadron Leader Kellett before the war. He continued later to North Africa to serve under Montgomery in forming a squadron of Wellingtons to attack tanks.
Harris was also involved in a propaganda film that was made in to boost civilian morale. He flew the aircraft in the film but obviously not mentioned in the credits for reasons of censorship. Here is the link to the original film ‘Target for Tonight’.