On the subject of those at lower band units who wish to move, would it not be sensible for NATS to post all new trainees to lower band units in order to obtain they're initial validation. Once valid, they would then allow the more experience staff at these units to move on if they so wished. These experienced staff would also have a higher chance of validating at the "busier units" than an ab initio. There would be a generally happier workforce over all as everybody would have a chance to move if they wanted to and it would lead to a higher percentage of trainees validating at their initial posting and thereby securing their long term job prospects.