where does the liquid end up

[AI101]

I heard from a few people that all the waste water used in aircraft is chuked out in the air, is this true?

I also heard that only the solids from the toilets are stored and the rest is again out the back?

[Litebulbs]

Waste fluid poured down galley and lav sinks is dispersed into the atmosphere. All lav waste (down the toilet bowl) is stored on board and removed after landing.

[BAe146s make me cry]

Depends on the design of a/c system.

One common design is, there are waste tanks for all lavatories.

Some use individual tanks immediately located under your 'seat'.
These will be serviced at each turnround by means of a fill & drain
system. A flush motor & adjacent timer forms part of the system.
They will have their own fill & drain service point. Older DC-10/BAe146.

The 'newer' type of system is the vacuum system. This vacuum
system is derived from the aircraft pressurisation or pneumatic system
but also uses the same bleach based medium to rinse. Gate valves & timer's again employed. The waste tank is located elsewhere ( underfloor/adjacent freight bays etc). Filled and drained in a similar way to above (Far less service points) Embraer190/AirbusA330.

Typically, the waste that is actually designed to be dumped
overboard in flight is lavatory & galley sinks through heated drain masts.
This explain's the coffee slicks that can be found immediately behind drain masts & the inevitable blockages that occur because Inflite Crumpet or
Pax pour glue down it (or equivalent of).. :hmm:

I'm not rated on the A380 (Doesn't look like I will be for a while) But more than likely, the shower system certain customers may have installed will
probably also exit through these drain masts (Reduce weight where poss).

The 'blue ice' incidents are more about fill & drain leakage issues
and should be rectified promptly. Better individual system description can be found in an applicable Aircraft Maintenance Manual, Chapter 38 (Water/Waste).

BAe146??? :{:{:{

[CirrusF]

One common design is, there are waste tanks for all lavatories


This wasn't always the case. In the 1960s there were a series of mysterious, isolated, random cholera outbreaks in a swathe across western Europe. Eventually investigators worked out that they were all under the flight-path of long haul aircraft from the sub-continent....

[Wodrick]

A couple of points.
1. Bowl rinse is done with potable water in vac systems
2. I do not know of a single aircraft type that dumped toilet waste overboard Deliberately, dropped blue ice yes but dumped no.

[BAe146s make me cry]

Wodrick

Thanks for your correction re: potable water for vac systems.
Reviewed the Emb195 AMM last night - vac system as above.

I won't edit out my mistake because I'm an honest Engineer :O

Regards

BAe146??? :{:{:{

[NutLoose]

The mighty Chinook has pee tubes that exit the underside drains to atmosphere :) I suppose if a number two was in order you would have to hang your a** off the aft ramp :}

[HAWK21M]

All modern commercial airliners use either the recyclable or vaccum type toilet system.The Waste is collected in tanks & serviced on the ground.Only galley potable water is drained overboard.
regds
MEL

[NIGHTFR8R]

if you get the chance look up billy connolly's sketch about the "jobbie wheeker" which will give you a detailed account of what happens to a number 2 when deposited in an aircraft toilet.:)

[Swedish Steve]

The B787 will have vacuum waste tanks that store galley water as well as toilet waste. There are no drain masts on this aircraft.

[anartificialhorizon]

The original post always reminds me of a pal of mine who said to me, if you don't like a particular country wait until you are flying over it and take a pee in the sink......:ok:

Water from sinks, galleys, drip trays etc (grey water) goes overboard through the drain masts.

The brown stuff goes into tanks /stays in storage below the toilet bowl.

[tonytech2]

Yes, there were aircraft that discharged toilet waste overboard - Back in 1950's at KIDL I regularly worked a DC-4 belonging to a large oil company. It, along with two DC-6 aircraft regularly flew from the Mid-East to New York. - the lavs had a sign on the door, "DO NOT USE OVER INHABITED LAND".
When you looked at the bottom of the bowl, you saw a stainless steel pipe continuing on down to daylight -
Outside was a stubby open-ended extension of said tube.
No valves, never clogged.
Their DC-6 aircraft had standard toilets for the type.
I admit its the only aircraft like that I ever saw - there was a precedent though. In America, in the good old days, the passenger trains had toilets with signs on the door, "DO NOT USE IN STATIONS".

[toolowtoofast]

don't pax trains in the UK have that sign now?

[AI101]

I KNOW THE TRAINS IN INDIA HAVE NO SUCH SIGNS BUT IF YOU LOOK IN THE TOILET ITS JUST A HOLE TO DEPOSIT YOUR s*** ONTO THE TRACKS.

[whatbolt]

Thats why its very important to not use the toilet " when on the ground". Its not nice having to go around with the shovel when you lot have pushed back.

[BelArgUSA]

The 727s have a waste mast under the belly.
That is the way the "liquids" go...
xxx
Reminds me of an incident with a 727-200 sometimes in the 1970s.
The waste mast is heated... obvious reason.
I do not recall the airline, irrelevant anyway.
Was (I think) somewhere in the Midwest USA...
A 727-200 was cruising, mast heater failed. Icicle grew under the belly.
Airplane started its approach down into... warmer temperatures.
Big icicle flew into nº 1 or nº 3 engine. Engine failed. FOD...
xxx
Was some damage to the first stages of the JT8D engine.
They analysed the damage on the blades... Found traces of human feces.
So, on our crew bulletin board, a note -
"Amendment to 727 MEL. Cannot dispatch with mast heater INOP".
xxx
One of our illustrious (PanAm) F/E added a note below...
"Where were YOU when the sh*t hit the fan...?"
xxx
:E
Happy contrails

[ZimmerFly]

Whatbolt

Many moons ago while paxing SYD-MEL-PER on Ansett I was informed by a Junior CC that I could not use the dunny during the transit ! Fortunately the more Senior CC had not been trained on the railways and allowed my visit. :rolleyes:

[Wodrick]

While I don't want to argue with an illustrious poster that post about the 727 is wrong. The 727, like all of it's era sends "grey" water out via drain masts. Human waste is stored in tanks under the toilet and dumped on arrival. The problem with that particular incident, and I'm sure others, was a leaking dump valve on the fwd toilet. This in turn led to the fitting of a secondary bung to contain leaks and to those such as myself to carry out regular pressurised aircraft leak checks.