The alarming noise ensues when you press the “flush” button in an airplane toilet and the bowl’s contents are magically sucked away into oblivion. With the noise and essentially “clean” bowl as a result, there’s clearly some sort of vacuum cleaner-type effect at work.But how do aircraft toilets work? Flushing the toilet on an airplane opens a valve between the pressurised cabin and a tank that remains at atmospheric pressure. However, retired aircraft engineer Nigel Jones explains that the complexity of the implementation still varies from aircraft to aircraft. “It had a tank at the front for the forward toilets and another for the five or six toilets at the back.