Beeayeate
The wing with the Full tip tank was trestled to save time by not de-fuelling it. The leckies and armourers did their bit after the fuel transfer and leak checks were carried out and the tank proved to be 'S'. It was not unusual for so called 'S' tanks to either leak or not transfer at all requiring a further change of tank. We were using all metal tanks and they were bl##dy awful things.
CC