When it comes to aviation, there's a lot that your average passenger doesn't know. You're pretty much just blindly trusting the pilots and stewards to get you back on terra firma each time, and few people really understand how the whole process works. How does a heavy tin can manage to stay in the air? How come drinking while flying always gets you twice as drunk? What really goes in the cockpit? And what's the deal with the brace position? Apart from the professionals, nobody seems to know the answer.
One of the most prevalent factoids about flying is what happens to your poop: the so-called "blue ice" phenomenon. Many people believe that, when passengers flush a plane toilet, the waste is immediately ejected from the WC and ejected into the troposphere; then it freezes as it falls to Earth, and in many urban legends the lumps of icy faeces then cause havoc. But is there any truth to these stories? Apparently: none whatsoever.
In an interview on Australian breakfast show Sunrise, a commercial pilot for Jetstar came clean about what happens to crap on aeroplanes. Pilot Brett Manders stated: "I can safely say there's no number ones or twos that goes out into the atmosphere. All the waste goes into a tank, and is held at the bottom of the rear of the aircraft. It doesn't go overboard."
Plane toilets typically have a 'closed waste system,' which works much like a common house toilet. Normally, the ground crew disposes of all the sewage collected in the septic tank once the plane lands safely, and even if the pilot wanted to empty the tank midflight they wouldn't be able to, since the valve to do so is located on the outside of the plane and is opened by the ground crew on the runway. There have been rare cases where these tanks might leak, but this leakage would be alerted to the pilots, who would then presumably perform an emergency landing. All in all, the blue ice phenomenon sounds more and more unlikely.
Manders also reassured viewers that, contrary to what movies might have you believe, you can't actually open the doors of a plane while it's in flight. He stated: "Imagine a football that's pumped up really hard and you're trying to press it in, that's what you're trying to do. The doors to the front of the aeroplane open 'in' initially and then 'out'. The pressurisation in an aeroplane adds hundreds of kilos of pressure each square metre of the door, so humans are not strong enough to open the door."
So there you have it guys: none of us was ever in any danger of being hit by falling frozen poop ejected from a plane. I bet that's a weight off your mind, right? I guess now you can easy next time you flush while flying.
