In case you hadn't noticed, most of SA is in the grips of a mid-week cold front. The cold weather conditions have since affected quite a few early morning flights with knock-on effects.
UPDATE: Flights on track as Gauteng sees third cold front in five days
SA Airlink confirmed "various flights departing Johannesburg this morning were delayed due to ice formation on the aircraft".
These are specifically Airlink’s JNB KIM JNB SA8421/2 and SA8423/4. We regret the inconvenience caused to your travel arrangements.
Passengers also have shared how some Mango flights at OR Tambo International and Lanseria have also been delayed. Kulula and FlySafair confirmed its flights were currently on schedule.
READ: Fire and ice: South Africans are freezing while Europe’s heatwave melts an entire glacier
So how exactly are planes delayed due to cold weather?
According to the South African Civil Aviation Authority all holders of an Air Operators Certificate (AOC) are required to have an All Weather Operations Manual specific to their type of operations and type of aircraft informed by the aircraft manufacturer, which is then approved by the SACAA. Therefore, the procedure is not the same for all adverse weather operations.
But it isn't the cold per se that's messing with the schedule. When flying at 40 000 feet an aircraft can withstand -57 degrees Celsius. Cold air is denser than warm air, so planes are actually more efficient during colder temps, says Travel and Leisure.
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The problem with the cold is the ice and the snow that accompany it. Frost build-up on the wings are problematic as it has the potential to obstruct airflow. If ice builds on the wing, for example, it can change the pattern of airflow and influence the aircraft's overall performance.
In the air, snow or frost won't accumulate because of the speed of commercial planes, yet on the ground this is a different story. Smaller planes sometimes struggle more with ice build-up as they tend to fly much slower than larger jets.
Business Insider also reports that while planes can be de-iced with a cocktail of anti-freeze (usually a mix of water and glycol alcohol), iced-over runways can be a massive safety issue.
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