My own opinion is that because they originally put a blanket ban in place the ban will not be lifted until the "cloud" blows away or dissipated sufficiently.

If they suddenly turn round and say "we got it wrong, it is in fact safe to fly" then there would be huge outcry from the airlines and the public.

What should have happened was:

1) Volcano erupts, plume covers Scotland. NATS announces temporary closure of airspace until sufficient test flights can be carried out.

2) Test flights get carried out.

3) Decision made on result of test flights.


Instead by putting a blanket ban in place they have created a monster.