An aircraft lavatory is a small room on an aircraft with a toilet and sink. Airplane toilet is a sanitary and hygienic unit located on board the aircraft. It is used on passenger aircraft, making a long air flight.
History
An early aircraft fitted with a toilet was the 1921 Caproni Ca.60, However, it crashed on its second flight and never saw service. The Handley Page H.P.42 airliner, designed in 1928, was fitted with toilets near the center of the aircraft.
The British Supermarine Stranraer flying boat, which first flew in 1934, was fitted with a toilet that was open to the air. When the lid was lifted in flight, airflow produced a whistling noise that led to the aircraft being nicknamed the “Whistling Shithouse”. The Short Sunderland flying boat, which saw military service from 1938 to 1967, was comparatively well equipped, carrying a porcelain flush toilet.
During World War 2, large bomber aircraft, such as the American Boeing B-17 Flying Fortress and the British Avro Lancaster, carried chemical toilets (basically a bucket with seat and cover, see bucket toilet); in British use, they were called “Elsans” after the company that manufactured them. These often overflowed and were difficult to use. The intense cold of high altitude required crews to wear many layers of heavy clothing, and the pilot might have to take violent evasive action with little warning. They were unpopular with bomber crews, who would avoid using them if at all possible. Bomber crew members sometimes preferred to urinate into bottles or defecate into cardboard boxes, which were then thrown from the aircraft.
Small aircraft
During World War II, smaller aircraft such as fighters were fitted with devices known as “relief tubes”. These consisted of a funnel attached to a hose that led to the outside and which could be used for urination. These devices were awkward to use and could become frozen and blocked in the intense cold of high altitude.
Such devices are still sometimes fitted to modern military aircraft and small, private aircraft although they are difficult for women to use. Male glider pilots undertaking extended soaring flights may wear an external catheter that either drains into a collection bag or is connected to tubing that dumps the urine to the outside. If the latter approach is used, care must be taken when designing the system so that the stream of urine does not make contact with other parts of the aircraft, where it may eventually cause corrosion.
Another solution to urinating on long military patrols, especially in modern naval patrol craft where a pilot is strapped to his seat, is the use of a sponge-containing zipper storage bag, which is disposed at the end of the flight.
Passenger aircraft
Lavatories per passenger provided aboard aircraft vary considerably from airline to airline and aircraft to aircraft. On board North American aircraft, including low-cost, charter, and scheduled service airline carriers, the normally accepted minimum ratio of lavatories to passengers is approximately one lavatory for every 50 passengers. However, in premium cabin and business cabins, passengers may have access to multiple lavatories reserved primarily for their use. These ratios of lavatories to passengers vary considerably, depending upon which airline is being used with some first class passengers having one lavatory for every 12 passengers. Additionally, many of the larger long-haul airlines elect to equip their aircraft with larger lavatories for this particular group of passengers willing to pay higher fares.
Smaller commuter aircraft and regional aircraft designed for short-haul flights may not be equipped with lavatories. Recently, many regional airlines in North America have commenced the trend of eliminating the refilling of hand-washing basin potable water tanks in order to reduce weight, fuel consumption, and service costs.[citation needed] To facilitate sanitation, disinfectant hand-wipes are provided.
The principle of the toilet
In an airplane, as a rule, there is a water supply system and a waste disposal system (sewage system).
Water supply system
The water supply system is filled with drinking water before departure to a special tank of clean water. The water charged into the water tank under pressure, created in the tank by air compressors, is distributed to consumers.
Usually water is used to drink passengers (usually after boiling in special reboilers), in wash basins, and (on some types of aircraft ) to flush the toilet after each pressing of the button.
Sometimes there is a separate water supply for the toilet.
Disposal system
On different types of aircraft, the system for removing solid waste has different principles of work:
So, on some, scum is washed off with water, after which all the fused products get into a special drain tank, where the cargo is stored and the entire flight accumulates.
Sometimes the waste from the toilet is sucked into a special tank with a vacuum, after which the residues are washed off with a relatively small amount of water.
There are closed-circuit sewerage systems, operating on the principle of recirculating the liquid for flushing the toilet, which is initially taken from a separate tank, refueled before departure. In flight after flushing, the waste is filtered, and the filtered liquid is sent to a second flush of the toilet bowl. In this case chemicals are added to the tank for disinfection and deodorization of the liquid.
After landing the aircraft, all sewage, both filtered and liquid, are merged by suction into the tank of a sewage machine, and are exported. If necessary, the same machine refills the tank with fresh chemical. liquid through the filling nozzle on the toilet service panel.
On airplanes that were developed before the mid-1960s, open waste disposal systems were also used, when the toilet bowl flanged with a valve simply went overboard. Such toilets were, for example, on the IL-14.
On high-altitude aircraft to avoid depressurization of the cabin on the fan pipe, a two-valve sluice was installed. This scheme worked toilets on the Tu-104 and the early modifications of the IL-18.
Location
In different aircrafts different location and number of cabins:
In Boeing 747 there are 11 toilets: two at the beginning and the end of the cabin, four in the middle of the cabin, and three toilets on the second deck;
In Boeing 767 5 toilets: one – at the beginning of the business class, two – between business and economy classes, two – in the middle of the economy class.
There are three toilets in Tu-154, A-320, Yak-42 and Boeing-737 airplanes: one is at the entrance to the liner, two – at the tail;
In small aircraft such as Yak-40, ATR-72, CRJ200, only one toilet is installed, usually in the tail section.
Depending on the year of manufacture, the airline and the model of the aircraft, the number of toilets and their location may vary.
The rules of using the toilet
On board an aircraft for security purposes:
It is forbidden to use the toilet during take-off and landing
Before pressing the drain button, it is necessary to cover the lid of the toilet bowl
Toilet paper, and, especially, diapers and pads should be thrown into special urns
You can not smoke and use dangerous and smoke-emitting products, as this triggers the alarm of the smoke detection system in the airplane
Types
Lavatories on modern aircraft are very expensive, and include features that have required substantial upfront and long term investments by the world’s airlines to design and develop. Airlines and aircraft manufacturers continue to investigate ways to improve lavatory design technology to increase functionality and reduce costs of production, while maintaining adequate levels of safety, hygiene and amenity.
For this reason many modern lavatories are now no longer of the “chemical toilet blue water recirculated electric flush” variety. Instead lavatory manufacturers have progressed to “vacuum flush” technology to eliminate solid and liquid residue from the basin, patented in 1975.
Some of the advantages of vacuum flush technology systems, from aircraft designers’ perspective, is the increased safety attributes through less risk of corrosive waste spill over into recesses around the lavatories which can be difficult to protect. Additionally, vacuum flush systems are considered to be less odor-inducing and substantially lighter in weight, saving fuel by reducing the need to carry large reserves of blue recirculating water.
Fixtures
Ashtray (even on airlines that have banned smoking)
Built in waterless toilet with push button flush
Call button – for assistance
Electrical outlet
Garbage can – small push door to discourage use of toilet to dispose of non-human waste items
Handle bars to assist elderly or disabled passengers to get up from toilet
Handwash faucet and sink (with taps or push button to dispense water)
Mirror
Paper towels
Soap dispenser
Toilet paper dispenser or linens
Paper cup dispenser
Sign on door to indicate lavatory in use or not in use
Toiletries – handcream, facial tissue, sanitary napkins, air sickness bags
Change table for infants located above the toilet
Fitted cabinets may contain additional toilet paper and other toiletries, but they are often locked. The toilet and sink are often moulded plastic or a stainless steel sink, the floor is usually a non-slip surface. In newer aircraft, the executive or first class lavatories are roomier and offer more toiletries and other comforts.
The presence of an ashtray is sometimes commented upon, given that smoking has been long banned on flights in many parts of the world. However it is a requirement of the Federal Aviation Administration that ashtrays continue to be fitted to the doors of aircraft toilets. This is due to the fire risk caused by the possible disposal of illicitly consumed smoking materials in the toilet’s wastebin. In 2011, a Jazz flight from Fredericton, Canada to Toronto was prevented from taking off because an ashtray was missing – the aircraft instead flew to Halifax without passengers to have a new ashtray fitted.
Waste bins are fitted with Halon fire-extinguishing bottles and “oxygen-smothering flapper lids”, and the toilets equipped with smoke detectors. Over time these protective devices have been incorporated into aircraft lavatory designs due to fires that have started when the careless smoker of the past or the clandestine smoker of the present has incorrectly disposed of smouldering smoking material. Also, the danger from accidental fires in the toilet is considered to be higher than in other parts of the aircraft cabin as the fire would have more time to develop before being noticed by a passenger or crew-member.
If the toilet’s fire extinguishing or smoke detection systems are inoperative, the aircraft is still permitted to fly, provided the toilet is barred to passengers and only used by crew members.
Servicing
Each aircraft equipped with a bathroom or lavatory needs to discharge its waste somehow. After an inbound aircraft arrives it is the duty of the “lav agent” to flush the lavatory system. In places where fewer or smaller aircraft are being serviced, a “lav cart” (essentially a small lav truck pulled behind a tug) is used to service the lavatories. At airports with higher volumes of passenger traffic, lavatory agents usually use trucks adapted with large tanks on board that do not need to be emptied as often. These trucks are equipped for access to the waste ports of the aircraft, which can be out of reach by other means.
In military aircraft
Military aircraft produced in the USSR until the 1980s (even with a long duration of flights), as a rule, do not have a toilet: each crew member has hermetically sealed containers for urine (the so-called urinal, sambachok). In case of need defecation, no measures are provided.
Sometimes there are constructive differences. For example, on the Tu-22M two urinals are installed in the underground of the cabin, to which four hoses with nozzles, from each workplace of the crew members, are connected.
Some military aircraft produced by the USSR (for example, Tu-142 ) still have airborne toilets, but their design is rather archaic, which makes it difficult to use them.
Crews of transport military aircraft often independently equip toilet seats, if they are not provided for by the design. For example, on military transport aircraft like An-12, for the management of the needs of passengers, on the deck of the cargo cabin are put ordinary household, plastic or galvanized 8-12-liter buckets with lids and (or) plastic bottles.
Since the 2000s, they have been trying to take portable toilets on board old transport planes. The change in the design of aircraft is strictly prohibited, so nothing changes on combat vehicles.
Military aircraft of later issues are regularly equipped with toilet equipment, the design of which depends on the class of the car and the way of landing of the crew members. So the Il-76 M and An-124 are equipped with full toilet rooms from passenger airliners, there is a small toilet module in the Tupolev 160 in the hermachine, on the Su-34 they use sabbaths for each of the crew members.
The most complex and most expensive Soviet airplane ARL -50 with an air crew of 15 people was initially without a bathroom – a conventional bucket was placed in the liner’s stern. Only after the intervention of Chief Marshal of Aviation PS Kutakhov, they thrust the side toilet of a very unpretentious design.
Source from Wikipedia