Who's in charge?
Just finished reading a pretty good aviation novel, and it made me wonder (as part of the plot involved refusing a damaged aircraft permission to land) - who has the final say? Does the aircraft captain have a right to land at any airport, or can the ATC or other authorities totally deny them a landing? I thought I read years ago that an airport can never really be declared "closed", and ATC can only really advise on landing or not.
And what about taking off, can a captain go without permission - assuming it is clear and safe to do so?