Mirabel International Airport is an airport in Mirabel, Quebec, near Montreal. It uses the IATA Airport Code YMX. It was constructed as part of a major project by the Canadian federal government for Montreal, originally to replace Montreal-Trudeau International Airport (then 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.
Mirabel International Airport is mainly used for charter flights and cargo flights.