For many, a trip to the bathroom during a flight is escapable and the unusual signs stuck on the lavatory walls probably raise several questions. For starters, why is the flush so loud? And why can’t you flush while seated?
It turns out that the ‘whoosh’ noise that is so loud it sounds as though you and your fellow passengers will be catapulted from the plane, is actually an air vacuum.
Once a passenger has done their business and presses flush, the pressure of the airplane cabin ‘evacuates’ the toilet bowl.
A trapdoor in the base of the toilet opens and a blue solution called Skykem fills the bowl.
As the bowl is waterless, the powerful vacuum suction has to be so strong it leaves nothing behind, while Skykem is swirled around to remove odours.
From the toilet, the waste is sucked through pipes to the rear of the plane where it is dumped into a tank until the end of the flight.
James Kemper invented the modern airplane toilet to remove problems like spillage – which can turn the myth of falling faeces into a reality.
Since pilots can’t clear the tanks during flight, the waste remains in tow until the aircraft has landed where it is removed by trucks.