Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

A320 aircon ,.mist on take off till around 7,000ft

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

A320 aircon ,.mist on take off till around 7,000ft

Thread Tools
 
Search this Thread
 
Old 30th Aug 2019, 19:47
  #1 (permalink)  
Thread Starter
 
Join Date: Sep 2010
Location: by the seaside
Age: 74
Posts: 559
Received 17 Likes on 13 Posts
A320 aircon ,.mist on take off till around 7,000ft

Venice BA..31/20 temps..Pouring up from the window fairing into the roof fairing..possible oil smell but at my age I cant even smell myself.
Not uncommon in the tropics but never seen it for so long .
Stopped RHS around 4,000ft.
normal?
blind pew is offline  
Old 30th Aug 2019, 19:57
  #2 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,419
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by blind pew
Venice BA..31/20 temps..Pouring up from the window fairing into the roof fairing..possible oil smell but at my age I cant even smell myself.
Not uncommon in the tropics but never seen it for so long .
Stopped RHS around 4,000ft.
normal?
If You had loads of moisture that is very normal during summer time even in Europe nowadays. The other day we were sitting on the tarmac with 36 degrees and 80% humidity. The RVR inside the cabin was maybe 20 cm. We landed in Delhi 8 hours later only to find the same ground temperature and humidity. Guess they call it global warming or so.
sonicbum is offline  
Old 30th Aug 2019, 20:03
  #3 (permalink)  
Thread Starter
 
Join Date: Sep 2010
Location: by the seaside
Age: 74
Posts: 559
Received 17 Likes on 13 Posts
Thanks in my day the packs were off for takeoff..

Havent seen it 737s and pax them 20 times a year.
blind pew is offline  
Old 30th Aug 2019, 21:56
  #4 (permalink)  
 
Join Date: Jun 2014
Location: Mordor
Posts: 335
Likes: 0
Received 0 Likes on 0 Posts
It happens a lot on the 320. Don’t know exactly why, but seems to be peculiar to the type. Didn’t see much of it on other a/c
Sidestick_n_Rudder is offline  
Old 31st Aug 2019, 07:00
  #5 (permalink)  
Thread Starter
 
Join Date: Sep 2010
Location: by the seaside
Age: 74
Posts: 559
Received 17 Likes on 13 Posts
Thanks..although I was supposed to start a course on the 319/20 before I lost my license I’ve only flown on orange and green liveried aircraft before and never seen a hint of it. Obviously somfink to do with smoke and mirrors..apologies.
blind pew is offline  
Old 31st Aug 2019, 07:29
  #6 (permalink)  
 
Join Date: Nov 1998
Location: 🇬🇧🇪🇸
Posts: 2,097
Received 1 Like on 1 Post
Misting like that is perfectly normal and occurs when the duct temperatures are turned down to minimum for rapid cooling during high humidity. I avoid it by keeping the duct temperature above minimum setting, but that reduces the rate at which the cabin cools. In addition, our cabin crew make a PA to reassure infrequent Airbus passengers that the misting is normal and will clear when the cabin reaches a comfortable temperature.
Nightstop is offline  
Old 31st Aug 2019, 08:15
  #7 (permalink)  
Thread Starter
 
Join Date: Sep 2010
Location: by the seaside
Age: 74
Posts: 559
Received 17 Likes on 13 Posts
Thanks but 31/20 ain’t actually high humidity..the new girl I informed of the long duration hadn’t got a clue and judging by the mixing a Yorkshire pudding on the side stick by the skipper after leaving the hold he didn’t have the wherewithal to minimise the phenomenon.
Totally different to the way out with a personal mini hero of mine up front (small world of glider aeros and adventurous mountain fliers).
blind pew is offline  
Old 31st Aug 2019, 08:47
  #8 (permalink)  
 
Join Date: Nov 1998
Location: 🇬🇧🇪🇸
Posts: 2,097
Received 1 Like on 1 Post
31/20 is a RH of 52.09%, that’s pretty high to me. “It is what it is”, as the kids say nowadays.
Nightstop is offline  
Old 31st Aug 2019, 14:22
  #9 (permalink)  
 
Join Date: Sep 2011
Location: FL390
Posts: 237
Likes: 0
Received 0 Likes on 0 Posts
Thanks but 31/20 ain’t actually high humidity..the new girl I informed of the long duration hadn’t got a clue and judging by the mixing a Yorkshire pudding on the side stick by the skipper after leaving the hold he didn’t have the wherewithal to minimise the phenomenon.
Wow.

although I was supposed to start a course on the 319/20 before I lost my license
Sounds like a lucky escape for the rest of us. Misting is perfectly normal on the A320 series but can be exacerbated in my experience if the flight deck and cabin target temperatures are set a long way apart. Airbus have been fiddling with the air conditioning architecture off and on for years.
Fursty Ferret is offline  
Old 1st Sep 2019, 00:03
  #10 (permalink)  
 
Join Date: Mar 2005
Location: N/A
Posts: 5,926
Received 391 Likes on 206 Posts
Not uncommon, the worse I've seen personally was on a Shorts 360 at Miami during start/taxi, as bad as the video. Our air force had a new on type pilot eject from a Sabre because mist was coming from the ducts and he thought it was smoke from a fire.

megan is online now  
Old 1st Sep 2019, 00:10
  #11 (permalink)  
 
Join Date: Jan 2004
Location: Here and there
Posts: 3,097
Received 14 Likes on 11 Posts
Originally Posted by blind pew
Thanks but 31/20 ain’t actually high humidity..the new girl I informed of the long duration hadn’t got a clue and judging by the mixing a Yorkshire pudding on the side stick by the skipper after leaving the hold he didn’t have the wherewithal to minimise the phenomenon.
Totally different to the way out with a personal mini hero of mine up front (small world of glider aeros and adventurous mountain fliers).
So a dew point of 20 degrees. What do you reckon the pack outlet temp might have been? Less than 20 perhaps?
AerocatS2A is offline  
Old 1st Sep 2019, 00:26
  #12 (permalink)  
 
Join Date: Mar 2012
Location: Dark Side of the Moon
Posts: 1,430
Received 207 Likes on 69 Posts
I have had this so thick in the tropics that you can't see row one from the Flightdeck. It is quite normal, I usually just make a quick PA to inform the passengers that the mist is just due to the high OAT. Never had any issues with it, normally stops below 10k.
Ollie Onion is offline  
Old 1st Sep 2019, 02:05
  #13 (permalink)  
 
Join Date: Nov 2006
Location: Tropics
Posts: 359
Likes: 0
Received 0 Likes on 0 Posts
The A320 pack sprays condensed water from the water extractor into the pack ram air inlet to help cooling of air conditioned air. You can see this if you peer into the pack ram air inlets during the walk around. Is this a contributory factor?

Like a few have mentioned, seems like this excessive misting only happens on the A320 series.
dream747 is offline  
Old 1st Sep 2019, 04:13
  #14 (permalink)  
 
Join Date: Jan 2001
Location: Australia
Posts: 725
Likes: 0
Received 0 Likes on 0 Posts
Its normal.
ITCZ is offline  
Old 1st Sep 2019, 06:45
  #15 (permalink)  
 
Join Date: Feb 2010
Location: earth
Age: 38
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Had it in a dark blue Volvo 850 with a newly re-gassed air conditioning on a particularly hot day.
cptkris is offline  
Old 1st Sep 2019, 07:53
  #16 (permalink)  
Thread Starter
 
Join Date: Sep 2010
Location: by the seaside
Age: 74
Posts: 559
Received 17 Likes on 13 Posts
Dream 747

Thanks that explains it. Thought it must be different to the kites I've driven.
blind pew is offline  
Old 1st Sep 2019, 08:12
  #17 (permalink)  
 
Join Date: Jan 2004
Location: Here and there
Posts: 3,097
Received 14 Likes on 11 Posts
I’ve had significant misting in BAe146 family aircraft (no, not oil fumes you wags!)
AerocatS2A is offline  
Old 22nd Sep 2019, 20:25
  #18 (permalink)  
 
Join Date: Mar 2005
Location: UK
Posts: 551
Likes: 0
Received 0 Likes on 0 Posts
Cabin crew here...

This is very common on the A320 series during the summer months, particularly when the OAT and/or relative humidity is high. Our operator has a PRAM that we can use to reassure any concerns during boarding.

As for the 737, I seem to recall that they have a water separator downstream of the PACKs,



TotalBeginner is offline  
Old 23rd Sep 2019, 10:01
  #19 (permalink)  
 
Join Date: Nov 2015
Location: BRS/GVA
Posts: 342
Likes: 0
Received 0 Likes on 0 Posts
As others have said, simply pack output below the dew point, its physics Jim. Only seen it significantly once on a 717 waiting on the tarmac for a thunderstorm to pass.
hoss183 is offline  
Old 24th Sep 2019, 09:59
  #20 (permalink)  
 
Join Date: Mar 2009
Location: Prague
Age: 51
Posts: 60
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by dream747
The A320 pack sprays condensed water from the water extractor into the pack ram air inlet to help cooling of air conditioned air. You can see this if you peer into the pack ram air inlets during the walk around. Is this a contributory factor?
.
No, it isn't. Water sparayed into the pack cooling airflow is "outside" of internal air conditon circuit, only helps with heat transfer on heat exchangers.
LEVEL600 is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.