Following on from flash8's posts, I'd like to add a small ditty.
My late father was one of the earliest recruits to the Air training Corps here in East Anglia. He and his mates were very keen to be air gunners. As part of their cadet training, they were often taken up to RAF Horsham St Faiths (now Norwich International Airport). Although it was mainly a fighter station, from time to time RAF Bombers would drop in after raids for fuel and other assistance. One day, whilst working on the station, they saw a bomber parked up near the tower. One cadet asked the chiefy looking after them, if they could go and have a look inside the turrets, being keen prospective gunners.
"Not just yet, son" quoth Chiefy, "They're still hosing the gunner out at the moment"
Dad's mate turned round to him and whispered " Sod being a gunner,Jack, let's go for radio operator...."