We do an aeronautical study, and that is a study that's all about safety. It's a hazard and risk analysis. It is very open and consultative with all of the stakeholders, including the operators, and it's primarily directed at safety.
Once we've done that, if that study indicates that the change would not pose any safety risk, it's then provided to the safety regulator, Transport Canada. Transport Canada then do their own analysis on it, and if they're satisfied as well that it doesn't pose a safety risk, they allow us to make the change, and that's what happened in the case of Mirabel.