Sponsor Message:
Aviation Photography Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Question About Overflying 747 Trails  
User currently offlineTin67 From United Kingdom, joined May 2004, 268 posts, RR: 3
Posted (9 years 5 months 1 week 1 day 16 hours ago) and read 3031 times:

I was at this afternoon and took this shot of a 747 overflying. I was intrigued to the 5 trails.

Any idea what the centre trail from the fuselage is?

http://www.airliners.net/addphotos/big/ready/KA6S1754_LHR_AF_OVER.jpg



Regards
Martin

[Edited 2004-11-14 21:19:42]

5 replies: All unread, jump to last
 
User currently offlineTupolevTu154 From Germany, joined Aug 2004, 2174 posts, RR: 28
Reply 1, posted (9 years 5 months 1 week 1 day 16 hours ago) and read 3015 times:

I heard once that the aircraft occasionally dumps some water, there is a pic of a JAL 744 with a fifth trail, AH here it is!


View Large View Medium
Click here for bigger photo!

Photo © Bailey - AirTeamImages



Or it could be the APU?

Tom



Atheists - Winning since 33 A.D.
User currently offlineAirplanepics From United Kingdom, joined Jun 2003, 2729 posts, RR: 42
Reply 2, posted (9 years 5 months 1 week 1 day 16 hours ago) and read 3008 times:

Most probably the APU.


Simon



Simon - London-Aviation.com
User currently offlineTin67 From United Kingdom, joined May 2004, 268 posts, RR: 3
Reply 3, posted (9 years 5 months 1 week 1 day 16 hours ago) and read 2997 times:

I though the APU when I saw it, but it seems to be coming from under the fuselage rather that the APU exhaust.

I see the text on Bailey's photo posted above by Tom that suggests the sink drains from the toilets. Interesting.

Cheers
Martin


User currently offlineJavibi From Spain, joined Oct 2004, 1371 posts, RR: 42
Reply 4, posted (9 years 5 months 1 week 1 day 15 hours ago) and read 2989 times:

As Bailey states, the fifth contrail is produced by water from the toilets and galleys sinks, which is thrown directly overboard via several drain masts.

The APU won't be running at cruise level, unless you have a serious problem.

Regards

j



"Be prepared to engage in constructive debate". Are YOU prepared?
User currently offlineErwin972 From Netherlands, joined May 2004, 500 posts, RR: 45
Reply 5, posted (9 years 5 months 1 week 1 day 14 hours ago) and read 2966 times:


To add to that: the drains under the belly are also heated to prevent icing. APU isn't running at cruise.


View Large View Medium
Click here for bigger photo!

Photo © Erwin




Kind regards,
Erwin



My gear: Nikon, Sony, Red, Sachtler etc.
Top Of Page
Forum Index

This topic is archived and can not be replied to any more.

Printer friendly format

Similar topics:More similar topics...
Question About This KLM's 747's Cowling? posted Thu Feb 20 2003 01:50:11 by Alphazulu
Question About Bangkok Suvarnabhumi International posted Sun Nov 19 2006 15:34:39 by Airimages
Question About Priority Screening posted Sun Nov 19 2006 06:37:48 by XAAPB
A Question About PS Jpeg Options posted Tue Nov 7 2006 10:02:25 by Stil
A Question About Doubles And Motive posted Sun Oct 15 2006 14:49:31 by Psych
Question About Phuket posted Sun Oct 15 2006 09:56:03 by Airimages
Question About Motiv. posted Wed Sep 13 2006 04:51:41 by COIAH756CA
Question About How To Avoid Jaggies posted Tue Aug 29 2006 13:24:58 by Coninpa
Screener Question About Catagory posted Thu Jun 22 2006 16:05:36 by AIRBUSRIDER
Question About Serial Numbers? posted Wed May 24 2006 01:31:56 by Walter2222