CNN —With extremely cold temperatures gripping much of the United States, travelers may be wondering how their planes are made safe for flying. Their mission was to see how their test plane, a long-range A350 XWB, withstood extreme cold. From cold to hotNew plane models undergo testing under extreme conditions before they're put into service. The cold-weather tests in Canada came only days after the MSN3 test plane completed high-altitude test in Bolivia. This kind of weather has made it an ideal spot to test aircraft.

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