Hot and humid air from outside meets cold air inside blown out from the air conditioning vents, temporarily creating fog inside the cabin, according to CNN. Two weeks ago, TikTok user Savannah Gowarty posted a video recording fog on a US domestic flight. The video attracted more than 13.1 million views, with many people expressing surprise and confusion at what happened. Experts say this is a natural phenomenon that only lasts for a short time and is nothing to worry about.
“On hot and relatively humid days, cold air from the aircraft’s air conditioning system mixes with warmer, more humid cabin air, causing its temperature to drop below dew point, creating fog “, a spokesman for the US Federal Aviation Administration (FAA), said.
When the plane waits for takeoff on the ground, the air in the plane’s cabin is kept cool by an external air conditioning system or the plane’s auxiliary engine, according to an FAA spokesman. Both provide cool air (usually much cooler than the ambient temperature), which can temporarily lower the condensation temperature of the air in the aircraft cabin enough to create fog.
Climate scientist Indrani Roy, who works at the University of London, said the environment on a plane creates the perfect conditions for condensation to occur in the cabin. That’s why the cabin surface appears wet. Condensation occurs when water vapor in the air comes into contact with any cooler hard surface, and there are a lot of hard surfaces inside an airplane. Roy also emphasized that fog in the cabin is not a cause for concern.
But even though moisture fog is absolutely safe, passengers are sometimes nervous, especially when they experience it for the first time, according to American flight attendant Rich Henderson. That’s usually because they mistake fog for smoke. For flight attendants, judging when passengers need a scientific explanation is part of the skills they hone on the job, accumulated through daily contact with different people. Anything unfamiliar to passengers can make them nervous, such as unexplained noises or engine sounds.
According to an FAA spokesman, fog in airplane cabins usually clears up very quickly. This is because cooler air (which causes the cabin air temperature to drop to the dew point) quickly warms above the dew point). When that happens, the fog will disappear, sometimes even lasting only 1 – 2 seconds.