Fairdealfrank, GVA, OSL and ZRH won't be any different to other EU cities as they're all under the same EASA and ECAA regulation which also covers non-member states of Norway, Iceland, Liechtenstein, Switzerland, Croatia, Macedonia, Bosnia Herzegovina, Kosovo and Montenegro. All of this is under the jurisdiction of the ECJ, it certainly is not scaremongering, hopefully we would remain within these agreements but AF/KLM, LH, SK, etc. won't allow UK to operate in Europe with different regulations, they're on record to this effect. So ECJ is a requirement. Complicated.