That is an excellent question. We have talked extensively about NORAD's role in aerospace defence looking outside of the continent in monitoring the continental approaches, but NORAD also has a very key role inside the continent in continental aerospace, specifically to look at the threat of an airborne attack from a malign actor like a terrorist. This obviously had its genesis in the 9/11 attacks.
NORAD continuously monitors what's happening in the skies above Canada and the United States. It maintains a high level of awareness about what is going on in the airspace, and not only in terms of where aircraft are moving. It's plugged into federal departments on both sides of the border to understand if there are any issues on board aircraft that are in flight. NORAD has an extensive array of procedures to deal with aircraft that may not be under positive control by pilots, and has a set of procedures to deal with that. That is a very important component of the NORAD mission.
Again, we see that co-operation extend in both directions across the Canada-U.S. border to deal with that potentiality. It is something that NORAD does pay a significant amount of attention to.