sentence: All waste is collected in tanks which are emptied on the ground by special toilet waste vehicles.
sentences_before: Toilet waste is never intentionally dumped overboard from an aircraft.
sentences_after: A vacuum is used to allow the toilet to be flushed with less water and because plumbing cannot rely on gravity alone in an aircraft in motion. The infamous blue ice is caused by accidental leakages from the waste tank.
concept_name: waste
headings: Common misconceptions Technology Transportation
categories: Society Lists Knowledge