UK ATC's bad air day - their circuit's dead, there's something wrong

This weekend, with commendably little fuss, the Air Traffic Control unit at West Drayton, near to Heathrow, unplugged their headsets and moved en-masse to brand new digs in Swanwick, close to Southampton.

These are the people who run the airspace over London and the South-East, and are responsible for shepherding uncounted tons of flesh and tin through some of the busiest skies in the world. It's a job of unparalleled complexity and pressure, and I don't think I'm being jingoistic when I say that UK ATC has a claim to being the best in the world. Certainly, that's what I've heard from pilots, a cynical breed not prone to praise where none is due.

It is not a simple job, moving a control centre. Downtime or loss of data are not options, even though you have to move systems managing communications with the aircraft, radar and links to other ATC centres here and abroad, not to mention all the IT support that goes with any enterprise. You want mission critical?

Initial indications were that things had gone smoothly. I kept an eye on things via Pprune, the UK aviation website to which I have an unhealthy and indefensible addiction. As expected, a thread started covering the move, and for the first page of posts all was congratulatory and good-natured.

Towards the end of the second, however, the story changes. Delays and flight cancellations are being blamed on system problems, and the following message is reported from the European control centre just after 2pm:

"WE HAVE JUST BEEN MADE AWARE OF TECHNICAL PROBLEMS AT LONDON TERMINAL CONTROL RELATING TO THEIR RECENT MOVE TO SWANWICK."

An hour or so later, the NATS emergency incident system, ATICCC, is activated.

So, what happened? The discussion continues on Pprune, with various people involved saying not very much but intimating that things may be serious - and, more worryingly, hardly unanticipated. Other voices are calmer - but no more informative.

Investigations continue...