An image of a person. If there is an OCCUPIED signal on the door it means that it is in use.VACANT means that there is no one there to use it.
There are toilets on airplanes, and toilets on the ground are drained by the kinetic energy of water, but airplanes can't carry that much heavy water to flush the toilet, and a vacuum drain is used.
Users press the button after the toilet, the toilet wall will flow a little water, some water inside is already added septic agent (dilution, flushing effect), while the following small valve will open, there is a huge vacuum suction will be sucked to the back of the aircraft special fecal tanks, and so the aircraft landed by the unloading workers to clean up.
Expanded Information:
Users flying notes:
1, do not eat before boarding the plane contains too much fiber and easy to ferment gas-producing food, so as to avoid bloating and loss of appetite on the plane.
2, do not eat too full, because eating a lot of greasy or high protein food, not easy to digest, will lead to bloating, diarrhea and easy to airsickness.
3. Don't get hungry on the airplane, because the changes in air temperature and pressure during flight make the human body need to consume more calories.
4, to eat high-calorie food, and the stomach empty easily nausea, so before you get on the plane should eat easy to digest and nutrient-rich foods.
5, in principle, one to one and a half hours before the plane, according to personal preference, choose to eat some bread, snacks, milk, lean meat and fruit, as long as the eight points can be full.
Baidu Encyclopedia - Airplanes