I am amazed at the amount of people looking for heads to roll when all those heads did was follow the rules.
I almost wrote, "Surely not the Nuremburg defence", but decided against. Instead may I refer you to the following quote:
Rules are for the guidance of wise men and the blind obedience of fools. (Solon, the Lawmaker of Athens, d. 559BCE)
Actually I think it was Douglas Bader!
As others have pointed out, there was obviously a problem with the rules. There is never zero volcanic ash in the atmosphere. We have always coped around the world until an invisible plume hit the UK. Thank heavens we have leaders like Captain Willie Walsh to sort things out.
Regards
S
