10W,
If Spain (AENA or the Government) don't want to abide by the European procedures laid down, then don't bother to be part of the CFMU system.
Can't fault your impeccable NW European logic, but it doesn't apply much when you get south of Paris. Unfortunately Spain, along with some other Mediterranean characters, sees compliance with international regulations as optional. Very nice to have the rules to hide behind when they suit you, but otherwise ignore. There are pages of commercial and business EU regulations which we Brits slavishly follow, only to see our fellow Europeans shrug and carry on doing things their own way. Same applies to aviation unfortunately. Seems to be directly proportional to the amount of garlic and olive oil in the local cuisine.
