Oh, dear, the latest set of "Just In Case" warnings suggests that if there's no deal and no "emergency deal/arrangements" flights may well not be allowed to and from the EU, something about recognising safety standards.
Can't see it happening myself, but it's been such an omnishambles the EU could hold it as a blackmail tool, "give us the deal we (the EU) want or your planes won't fly and your holidays are stuffed".
Where's Wally, he's supposed to be on stage in half-an-hour? Still stuck at Southend, bruv, waiting for his plane to go.