747 5th Contrail
Thread Starter
Joined: Dec 2001
Posts: 428
Likes: 8
From: Middle East
747 5th Contrail
Here's an interesting one....
http://www.!!!!!!!!!!!!!!/open.file/208678/L
http://www.!!!!!!!!!!!!!!/open.file/765736/L
both these 747's have a 5th contrail, what do we reckon is the cause? APU? Fuel venting? Water from the galleys?
http://www.!!!!!!!!!!!!!!/open.file/208678/L
http://www.!!!!!!!!!!!!!!/open.file/765736/L
both these 747's have a 5th contrail, what do we reckon is the cause? APU? Fuel venting? Water from the galleys?
Joined: Sep 2003
Posts: 45
Likes: 0
From: The Front Padock
These fifth and third contrails have been discussed lots before, lots of ideas and possibilities, some thoughts are the shape of the fuse and the condensation that it causes.
Why dont people do a search to check for info before posting new threads.
There is so much info on pprune - doesnt take long
Hay Ewe - there's another one "what a sixth contrail?"
Why dont people do a search to check for info before posting new threads.
There is so much info on pprune - doesnt take long
Hay Ewe - there's another one "what a sixth contrail?"
Thread Starter
Joined: Dec 2001
Posts: 428
Likes: 8
From: Middle East
Hay Ewe,
I do agree that there's lots of repetition on here but hey it's a forum and that's what they're here for - discussion.
You don't have to read the post if you find it tiresome old chap.
RU.
I do agree that there's lots of repetition on here but hey it's a forum and that's what they're here for - discussion.
You don't have to read the post if you find it tiresome old chap.
RU.
Paxing All Over The World
Joined: May 2001
Posts: 10,843
Likes: 328
From: Hertfordshire, UK.
Ooops, I thought I'd let that Vindaloo out quietly. 
Those CIA spy planes are everywhere. 
--------------------
"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.
Those CIA spy planes are everywhere. --------------------
"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.
The Reverend
Joined: Oct 1999
Posts: 2,020
Likes: 0
From: Sydney,NSW,Australia
The first picture could be waste water from the aft drain mast, the second picture clearly shows waste water from the forward drain mast. Both drain masts are electrically heated to prevent freezing.
Joined: Feb 2004
Posts: 1,410
Likes: 37
From: Australia
the second picture clearly shows waste water from the forward drain mast.
Boeing has told us a 5th contrail may be produced with the Packs in HI FLOW.
Rgds.
NSEU
Joined: Oct 1999
Posts: 668
Likes: 0
From: Adelaide
Would a single sink full cause a contrail 400 ' long " ?
Most assuredly. Water tank head pressure decreases at altitude ( think of the number of times there is no water in an upper deck galley in cruise ) and a marginal faucet that depends to some extent on system pressure to shut it off fails to do so, you have a non stop flow down the sink and out the mast.
Not an every day event but flights have definitely depleted a complete water supply via a faucet that fails to shut off and for whatever reason, goes unnoticed.
PS: I think Boeing were fibbing
Most assuredly. Water tank head pressure decreases at altitude ( think of the number of times there is no water in an upper deck galley in cruise ) and a marginal faucet that depends to some extent on system pressure to shut it off fails to do so, you have a non stop flow down the sink and out the mast.
Not an every day event but flights have definitely depleted a complete water supply via a faucet that fails to shut off and for whatever reason, goes unnoticed.
PS: I think Boeing were fibbing
