Montreal-Mirabel International AirportMirabel, Quebec, near Montreal. It uses the IATA Airport Code YMX. It was constructed as part of a major project by the Canadian federal government under Pierre Trudeau, for Montreal, originally to replace Montreal-Trudeau International Airport (then known as Dorval Airport).
The reason Dorval was flooded at the time was because jets all over the world used Dorval as a stopover to refuel. However, the advent of longer range aircraft caused airplanes that used Dorval to refuel to stop landing there. As a result, Dorval was no longer overcrowded.
Since Dorval's capacity problem was relieved, the sizeable Mirabel project remained unnecessary. It has since become quite costly to maintain the airport.
Montreal-Mirabel International Airport is mainly used for charter flights and cargo flights.