It’s currently a balmy 1°C at Iqaluit International Airport in Canada’s northern territory of Nunavit, although with the wind chill it feels more like zero.
Meanwhile, Al Ain International Airport, over 9,000 kilometres away, is a toasty 40°C, rising to 46°C by the early evening.
That means it is far too hot in Nunavit, but just right in Al Ain – at least if you want to test an aircraft for its ability to operate in extreme conditions.
That is why Airbus sent its new A350-1000 to the UAE last week, for three days of hot weather testing that ended with the twin engine jet passing with flying colours.
This is just part of a rigorous certification process that Airbus and all passenger aircraft must complete before being passed to begin commercial operations.
Al Ain has long been the preferred destination for Airbus hot weather testing, combining excellent facilities with high temperature. On its world’s tour of extremes, the A350-1000 has already been to Nunavut in February, where the mercury dropped to -31°C, and to Bolivia’s La Paz “El Alto” International Airport, which sits at 4,061 meters and is ideal for high altitude testing.
The aircraft has also completed noise testing in Moron, Spain, although only because the military air base there is equipped with sophisticated noise monitoring equipment rather than that the local inhabitants are particularly sensitive to loud noises.
Jean Philippe Cottet, the head of design development flight tests at Airbus, said the Al Ain tests are important for two reasons, the first being that its Rolls Royce Trent engines can operate properly in the equivalent of a UAE summer.
The second relates to passenger comfort, to make sure that the air conditioning units can deal with the temperatures on the ground. “It was 48 degrees in Al Ain last week, and the tests were very successful,” he says.
The A350-1000 is now ready to begin commercial services by the end of the year. “The certification applies to all conditions, up to extreme conditions,” Mr Cottet says. “What can be something of a challenge is starting engines at high altitude, which is why we go to La Paz.”
The news that Airbus was testing in Al Ain coincided with reports from Phoenix Sky Harbour in Arizona, where dozens of flights were cancelled after temperatures also reached 48°C.
This raised the question as to why airports in Dubai and Abu Dhabi can operate safely and without incident when it is equally hot.
The answer is a more complicated than the reading on a thermometer. Almost all the cancelled flights in Arizona were operated by short haul aircraft, mostly the Canadian-built Bombardier CRJ which is certified only to fly up to 47°C. Airbus, however, can keep working until it reaches 53°C and Boeing aircraft to 52°C.
The reasons why aircraft might not be able to fly in very hot weather are also more complex, ranging from the ability of certain mechanical and electronic parts to work properly, to the impact of heat on take-off.
Hotter weather makes the air thinner, meaning aircraft have to accelerate faster and for longer to take off. If an airport has shorter than usual runway, or the type of aircraft engine cannot generate enough thrust, then pilots may struggle to get off the ground.
None of issues are a problem for airports in the UAE which have everything legally required to keep passengers moving through some of the world’s busiest transport hubs. Except, of course, snowploughs.