Also, unless things have changed in the last few months, the people who attend the Stage 1 days are not NATS, they are from a third party recruitment company to whom NATS contract out the Stage 1 days.
I think since earlier this year (May/June 09 onwards) stage 1 dates were only available at NATS CTC, Hampshire for a short period when previously they were held in London, Manchester and Glasgow.
I presume NATS HR administer all stage 1s at CTC.
I believe since then, stage 1 dates are now held at CTC, Heathrow and Prestwick - not sure if Heathrow and Prestwick are contracted out?