There are no technical questions at stage 3 now. The interview is now just with HR and is a structured (competency based) interview. The questions will all be based around the competencies listed on the stage 3 prep document found on the NATS ATCO careers website:
http://atcocareers.co.uk/pdf/Hints-a...-Day-Three.pdf
You'll be asked two questions aiming to help you demonstrate each competency. For each question you will be expected to give a
specific example of a scenario you have been in that has tested that competency in a certain way, and then they will grill you further on that example by asking you about why you did what you did, why you chose a certain course of action etc.
Good luck
