If you’ve ever boarded a plane and found yourself squinting through a mysterious mist, you’re not alone.
Recently, passengers on a Jetstar flight from Bali to Australia were left wide-eyed and whispering as the cabin filled with what looked like thick smoke.
For a few tense moments, travellers could barely see the seats in front of them, and theories about the cause began to swirl faster than a jet engine.
One Australian on board summed up the confusion: ‘I’ve never seen it that bad.’ Another admitted the scene left her ‘freaked out’.
Was it a fire? Some kind of chemical spray? Or perhaps a sign that the plane was about to be featured in the next disaster movie?
As videos of the incident made their way online, the speculation only grew. Some passengers worried about their safety, while others wondered if they’d accidentally stumbled into a high-altitude sauna.
One passenger shared, ‘My Jetstar flight was like this from [Bali] to Sydney last weekend, I’ve never seen anything like it,’ and admitted they ‘thought something was wrong with the plane’.
But before you start packing a gas mask for your next holiday, let’s clear the air—literally.
What’s really going on?
Jetstar was quick to reassure passengers, explaining that the phenomenon is actually a common and harmless occurrence, especially on flights departing from hot and humid destinations like Bali.
The ‘smoke’ is nothing more than condensation—essentially, a cloud forming right inside the cabin.
Here’s the science: When the aircraft’s powerful air-conditioning system pumps cool, dry air into the cabin, it collides with the warm, moisture-laden air from outside.
The result? The water vapour in the humid air condenses into tiny droplets, creating a visible mist.
It’s the same reason you can see your breath on a chilly morning, or why your bathroom mirror fogs up after a hot shower.
Professor Martin Singh from Monash University puts it simply: ‘When the hot moist air from outside mixes with the cool air in the plane, it causes condensation.’
He adds that this is basic physics at work—warm air can hold more water vapour, but as it cools, the excess moisture turns into mist.
Not just a Bali thing
If you’re thinking this is a one-off, think again. Passengers flying into or out of other steamy destinations—think Cairns or Darwin—may also encounter this in-flight fog.
It’s more likely to happen when the plane has been sitting on the tarmac in a tropical climate, soaking up the heat and humidity, before the air-con kicks in.
And while it might look dramatic, Jetstar assures travellers that the mist usually clears quickly as the cabin air stabilises. There’s no need to worry about your safety, your luggage, or your hairdo.
Why does it seem so intense?
Some passengers on the Bali flight said they’d never seen the mist so thick. That’s because the effect can be amplified by extreme humidity, or if the plane’s doors have been open for a while, letting in even more warm, moist air.
Once the doors close and the air-conditioning gets to work, the sudden temperature drop can create a veritable cloud bank inside the cabin.
Should you be concerned?
In a word: no. The condensation is completely harmless and poses no risk to passengers or crew.
It’s not smoke, it’s not a chemical, and it’s certainly not a sign that the plane is about to make an unscheduled landing.
Video Credit: @thelambertons / TikTok
In fact, it’s a sign that the air-conditioning is working as it should, keeping you cool and comfortable as you jet off to your next adventure.
Have you seen the mist?
As air travel continues to evolve, passengers may encounter unexpected experiences like the mist phenomenon described here.
Understanding what causes these occurrences can help ease concerns and make your journey more comfortable.
What has been your experience with unusual sights or sensations during flights? Have you noticed mist or fog inside the cabin before, and how did it affect your trip? Do you think airlines do enough to explain these phenomena to passengers? Feel free to share your thoughts, or stories in the comments below. Your input helps create a more informed travel community.
Also read: Jetstar glitch leaves female doctor grounded in confusion
