airplane toilet lavatory
Mayukh Saha
Mayukh Saha
January 3, 2023 ·  4 min read

Airline Pilot Explains Where Your Poo Goes When You Flush It On A Plane

If you have ever used the washroom in an airplane, you must have had this burning question in mind- where does the poo go after you flush on an airplane toilet? While it does seem like a mystery- with our minds circulating through the most horrifying possibilities, the reality is not that bleak. Packets of human waste don’t get dropped from airplane vents as PUBG loots. And this is what a pilot on TikTok mentioned to his followers. If you think that the poo in the loo would pelt people from a height of 30,000 feet, you probably have watched quite a few Jim Carrey movies. The reality, as explained by Pilot Garrett, is far simpler, and dare we say- more practical. So what is the answer?[1]

What Does Pilot Garrett Have To Say About Airplane Toilets?

When you’re on an airplane and you gotta go, where does it go? Did you know that whenever you flush the toilet on the aircraft, it actually doesn’t dump out into the population down below? It goes through plumbing to the rear of the aircraft and the seal compartments when the ground crew at the destination will remove all that waste. On a 747- on a long-haul flight- toilets can be flushed over a thousand times, creating over 320 gallons of waste. That’s a lot.” While we can’t speak for our readers, this is certainly a revelation. And it turns out, Garrett’s TikTok followers are also unable to wrap their heads around this Airplane toilet conundrum. Interestingly, some viewers are also questioning the sanity of other individuals who believe the poo gets dumped out below. 


Ever curious where it goes when you’re on the airplane? 🤢💩✈️

♬ original sound – Flywithgarrett

One individual commented, “Other actually people that believe it would get expelled from the aircraft to the population below? And if so, do these people vote?” A second individual went on to state, “It still perplexes me that people think it just dumps out of the plane.” Yet another user commented, “Who even thought it drops below straight?” On the other hand, there were also certain people who explained why they had this idea that the plane would dump tonnes of poo as a method of waste disposal. One honest user commented, “Since I was a kid I used to think when over a sea the pilot flush it out. OMG.” Another user added, “Thank you for clearing that up. Hopefully, now we can let the matter drop.” A third person summed up the entire situation with, “Grounds crew deserves a raise.” 

Read: 7 Things Flight Attendants Notice About You When You Board an Airplane

The Scientific Explanation Behind Airplane Waste Management

This brings us to a more important question- how does the process actually work? So, airplane toilets usually have two methods of waste disposal system. The first one is the closed waste system, which is quite similar to your everyday house toilet- which simply flushes the water into an onboard sewage tank. Or, they use the vacuum waste system, which sucks the wastewater directly into the tank. While the water is up in the air, the latter usually gets its power from the difference between the air pressure that is situated outside the plane and inside the cabin- which then creates a roaring vacuum whenever a passenger would inevitably activates the flush. Under most normal situations, the ground crew usually disposes of the sewage after the flight lands. [2]

This image is only for aesthetic purposes.
Image Credits: Stock

The First Airplane Toilet Had The Right Idea

In 1975, James Kemper designed the first airplane toilet, which had a nonstick bowl, copious amounts of Skychem, and a powerful suction. So, when one flushes one such toilet, the trapdoor, which is situated at the base of the flush, would open, the liquid will be released, and everything will get sucked out. After that, the waste starts whizzing through the plumbing to the rear of the vehicle, where it gets stored in sealed tanks- far away from the other passengers until it finally touches down. On a long flight, there is a chance that the passengers might be flushing the toilet around 1,000 times, which would then create roughly 230 gallons of sewage- which is a lot. So when the plane lands, there are honey trucks which would be siphoning out the waste and then dispose of it properly. 

Blue Ice- What Is It?

In the event of a malfunction, the waste from the airplane toilet could start seeping out of the tanks. This usually occurs when the drain tube or the sewage tank has a leak, resulting in blue ice. For those wondering, this is what one gets when the blue waste treatment liquid from a plane’s toilet is exposed to absolutely freezing temperatures at high altitudes. It is usually understood that blue ice gathers outside the plane, but there are occurrences when it breaks off before landing.[3] 

When this gets loose, it often melts and then evaporates before it touches the ground. Interestingly- sometimes the blue ice doesn’t melt even when it touches the earth’s atmosphere- and requires human body heat to melt. This happened to a couple in Leicester, England who found blue ice in their hair, which then started melting and gave off the scent of urine. 

Keep Reading: Here’s What It Might Be Like To Travel On A Double Decker Airplane Seat


  1. Airline pilot explains where your poo goes when you flush it on a plane.” Lad Bible. Niamh Spence. December 27, 2022.
  2. Look Out Below! Where do airplanes dump their waste?” Slate. Forrest Wickman. February 12, 2017.
  3. What Actually Happens When You Flush an Airplane Toilet?RD. Elizabeth Manneh. April 28, 2022.