Bubb joined the RAF on 18 November 1940, at the age of 24. He received Gunnery training at RAF Kirkham, Lancashire, then Air Gunner training at the Flying Training School at Evanton in the Highlands. He was posted to Old Sarum airfield on completion of his training, to fly as an Air Gunner in Lysanders.
Bubb converted from Lysanders to Wellingtons in early August 1941, moving to RAF Waterbeach, Cambridgeshire, and shortly afterwards was assigned to a bombing run over Duisburg, in the Ruhr. His plane was badly damaged by anti-aircraft fire and a ME 110, but managed to drop their bombs and make it back to England. The damage meant the undercarriage could not be lowered and the pilot managed to use up the remaining fuel before making a successful belly landing.
Bubb was taken to Goodwood Hospital, then transferred to QVH. He had four operations over the next six months to reconstruct his jaw, and went on to remuster as an Armourer in his old unit.

Uniform, x-ray & bullet on display at East Grinstead Museum.