Vapour Discharge from 747 at cruise altitude
 

What is this being discharged from the underbelly of a BA 747 ? Presumably some sort of release valve for the air con system or something like that ?

Grey water, sinks, galleys etc drained overboard.

Interesting. Never knew all that goes overboard. As long as the toilet contents don't I suppose :)!!

Chemtrails. :E




Hey, somebody had to post that. ;)

so does it freeze to ice and drop straight down to skewer some poor clod on the ground?

..and furthermore isn't it a little uncomfortable to know that jets passing over our heads every day are dropping the contents of their sinks with God knows what sorts of jerms etc.

It does, just like the clouds.

Con...beat me by minutes.

The nasty stuff usually turns up as frozen blue ice....don't touch it.

747s ( at least prior to the -8 ) had open-to-atmosphere grey-water drains; lav and galley sink water flushed out immediately. The problem with that is that they sing like organ pipes at 500 kt.

As a result the 777 has valve-operated drains which only open when there's a certain pressure of fluid in the system. Edit: and according to a web search, the 787 has no external drains at all; all grey-water is captured in the lav tanks.

Surplus milk and beverages are disposed of via the toilets.

If they are dropping "jerms" then, no problem.
On the other hand, if it's germs that is a different matter !

Don't jerms feed on chemtrails?

The long dark streaks you see on the underside of some aircraft are often from coffee poured down the drains:

Photos: Airbus A330-223 Aircraft Pictures | Airliners.net

I couldn't be from hydraulic leakage, nobody would dispatch if that were the case would they?

How do they really know its coffee?? can they tell the difference between cafe and de-cafe? inquiring minds want to know

I am reliably informed that the red streaks on Concorde's undersides were caused by having to pour virtually full bottles of Château Brane Cantenac, etc., down the drain at the end of each flight.

:{

The first thing the crew seem to do after boarding an aircraft is pour stuff down sinks :* this pleases the loaders underneath the drain immensely .....but they soon cheer up once they see that the majority of the drain effluent in landing on the aforementioned crews crew bags that are waiting to be loaded in hold 5