"If you draw a great circle from here to Calgary, it passes up along the coast of China. South Korea. Sakhalin Island. Kamchatka. Then along the coast of Alaska and British Columbia for some distance. Then it cuts across the mountains and down into Calgary. All of this is a very commonly used air travel corridor, you understand? All of the jets between Asia and North America follow such a route. It does not pass over any sensitive areas. However. If you draw a great circle from here to Toronto, is totally different. It goes up across China. Then North Korea—very bad. Then a large part of Siberia that is definitely not a normal air traffic corridor. To get approval for such a flight plan is impossible. So we must follow the normal corridor until we are over western Canada. From there things get easier. But then we are so far from following a great circle route that it becomes necessary to refuel. Most efficient place to refuel is Calgary. That is where we filed the flight plan."