(CNN) — With extremely cold temperatures gripping much the United States, travelers may be wondering how their planes are made safe for flying.
The short answer: Along with regular deicing of planes before take-off, airlines put their aircraft through rigorous testing in some of the coldest places on the planet before they are ever pressed into service.
CNN followed a team of Airbus engineers, mechanics and test pilots back in 2014. Their mission was to see how their test plane, a long-range A350 XWB, withstood extreme cold.
The Airbus team left the warmth and comfort of their Toulouse, France, base to perform various extreme-weather trials on the test plane in frigid Iqaluit, the capital of Canada's eastern Arctic territory of Nunavut.
The ground and in-air tests included operating the A350 XWB in temperatures reaching down to -18 Fahrenheit (-28 degrees Celsius), thrust-reversed tests with snow and a local flight test.
From cold to hot
New plane models undergo testing under extreme conditions before they're put into service.
All new plane models must be tested in extreme environmental condition, from freezing to intense heat.
"Coming to an extreme place means we can break everything," Airbus' head of flight operations Pedro Dias told local reporters.
Extreme cold affects various parts of an aircraft in different ways. Metals, such as steel and aluminum, contract at different rates. Lubricants may lose their viscosity, creating friction and wear issues for moving parts. Meanwhile plastic and rubber parts could become brittle.
The cold-weather tests in Canada came only days after the MSN3 test plane completed high-altitude test in Bolivia. Next stop was Qatar for hot-weather testing.
'Premier cold-weather test site'
A boat sits along the frozen shoreline in Iqaluit, Canada. This kind of weather has made it an ideal spot to test aircraft.
Geoff Robins/AFP/Getty Images
For years Iqaluit, located on Baffin Island, has marketed itself as "a premier cold-weather test site."
Airbus has tested there since the 1990s, while the airport has also hosted other civilian and military aircraft makers such as Boeing, Dassault and Eurocopter to perform similar trials.
But cold weather test sites also appear in unlikely places.
In April 2010, Boeing chose McKinley Climatic Laboratory in Florida as the location for extreme-weather testing on its 787 Dreamliner.
In a test chamber the aircraft was given a "cold soak" and exposed to temperatures as low as -45 degrees Fahrenheit (-42.7 degrees Celsius) for hours.
Later, it had to endure temperatures as high as 115 degrees Fahrenheit (46 degrees Celsius), also for hours.
"These tests help us establish that our customers will get airplanes that work for them in all of the climates in which they operate around the globe (and in all seasons)," Randy Tinseth, vice president of marketing at Boeing Commercial Airplanes, said in a news release.
But extreme-weather trials are also affected by unpredictability of Mother Nature.
Initially scheduled for five days, Airbus' tests in Iqaluit were cut short, not because of an impending winter blizzard but because of a balmy temperature of -18 degrees Celsius -- too warm for the cold weather testing.