Flights will inevitably see many passengers visit the bathroom during the course of the flight. Some fliers may wonder, when the toilet is flushed – where does all the toilet waste disappear to? Clearly the loos cannot function the same as they do on land but does the aircraft dump the waste en route? Pilot Patrick Smith has revealed the truth about what happens in his book Cockpit Confidential.
The answered the question “Are the contents of airplane toilets jettisoned during flight?” in the aviation oeuvre.
Smith wrote: “Several years back, I was o a train going from Malaysia into Thailand when I stepped into restroom and lifted the toilet seat.
“I was presented with a mesmerising view of gravel, dirt and railroad ties all passing rapidly beneath me.
“Those who travel will encounters this now and again, and maybe it’s people like us who get these nutty myths off and running.
“The answer is no. There is no way to jettison the contents of the lavatories during flight.”
So what does happen? A combination of the vacuum, a small amount of blue sanitation liquid and non-stick coating are what helps wash waste away.
Tony King, Sales Director at SkyKem, which supplies hygiene technology to the aircraft industry, told Express.co.uk: “There is an airtight flap at the bottom of the toilet bowl to hold the vacuum.”
“When you flush the toilet this flap is released and the sudden aggressive noise is made by the vacuum sucking out waste.
“The toilet systems are emptied by vacuum to a large waste holding tank shared by many toilets.
“The vacuum is generated inside the waste tank so that waste and foul odours are all sucked into the tank.”
Smith explained the next step in Cockpit Confidential. He penned: At the end of a flight, the blue fluid, along with your contributions to it, are vacuumed into a tank on the back of a truck.”
The pilot added, tongue in cheek: “The driver then wheels around to the back of the airport and furtively off-loads the waste in a ditch behind a parking lot. In truth, I don’t know what he does with it. Time to start a new legend.”
However, although aircraft do not intentionally jettison plane waste, it has been known to happen accidentally.
According to Smith: “ A man in California once won a lawsuit after a piece of ‘blue ice’ fell from a plane and came crashing through the skylight of his sailboat.
“A leak, extending from a lavatory’s exterior vent sitting, caused runoff to freeze, build, and then drop like a neon ice bomb.
“If you think that’s bad, a 727 once suffered an engine separation after ingesting a frozen chunk of its own leaked toilet waste, inspiring the line ‘when the shit hits the turbofan.’”
If an engine fails, what does that mean for the aircraft? “If one engine fails mid-flight it doesn’t pose too much of an issue,” one pilot from a UK airline told Express.co.uk.
“It’s almost a non-event as aircraft are designed to fly for long periods of time on one engine.” Even if every engine fails, the plane should still be able to glide to a landing spot