ProM
Majority of European transatlantic traffic would be affected, inbound and outbound flights.
If they managed to get round the 'not flying through UK airspace' issue (possible), it could incur huge costs in extra fuel.
Upshot would be either a huge loss in profit for the airlines, or a big increase in ticket prices for those days. That in turn would mean less people would fly because of the hike in cost...
Because of the position of the UK and it's airspace, any closure not just of the major airports in the UK but the airspace itself, would have an enormous knock-on effect for mainland continental Europe and US/Canada.
The UK is a major hub, in both terms of airports and airspace.
Cuddles
there are many reasons why NATS should keep NSL and maintain a very strong presence in airports... your point is on of the more important ones. Unfortunately, NATS has quite a few loss making contracts on its books - I suppose it's a fine balance of getting contracts or making money.
I for one would happily see the company lose some money in some areas if we made an overall profit - it it meant that NATS could continue to be a 'leader in ATM'.
As soon as NATS stops or drastically reduces the number of coal face workers it has at either an airport or area unit the knowlwedge will go, and we could no longer be the expert we aim/claim to be.
If we don't have people doing the job on the coal face at airports, how can we convince customers that we are knowledgeable in the field, and therefore why would they come to us for other services borne out of experience of actually doing the job?
The sale of NSL would be a great mistake, I honestly believe that reducing pension liability i.e. voting 'yes' is one step further down the road to doing that.