Just found at from a mate at a non nats unit on the top a hill in yorkshire that the atca's take breaks for breakfast, lunch and dinner regardless. If it is busy and there are not enough atca's to cover then the atco's have to cover. the atca's leave at 2130 in the evening and leave the last controller (who is on a break) to cover if required. All to do with money and when there is an accident who is responsible? Management, ATCO's or ATSA's.