If I can "correct" the Wiki entry above....Bomber Command Gunners were not technically aircrew until the Air Gunner trade was formed in early 1940. Gunners were drawn from volunteers from the ground trades (often armourers) who were paid a small bonus for their extra work. Indeed, SNCOs often believed that these early gunners were skiving, and it was not unusual to see them allocated a full work shift after flying an operational sortie. The gunners wore a brass "flying bullet" badge on their sleeves until it was replaced by the AG flying badge when the trade of air gunner was formally promulgated, with the minimum rank of Sergeant as mentioned above.