User avatar
ZSOFN
Topic Author
Posts: 1380
Joined: Fri Jun 24, 2005 5:20 pm

What Atmospheric Conditions Cause This?

Wed Oct 30, 2013 10:30 am

Hi all,

I landed in Munich on SQ327 last week (77W) and noticed a large amount of water vapour being generated over the wings on final approach:

http://www.youtube.com/watch?v=ReJOhVv4N6U

I've noticed this before particularly on videos of landings at ZRH and AMS, so I was wondering if there was a particular temperature or humidity range in the atmosphere in that causes this?

N.B. Ignore some of the rather inane chatter between my friends & I during the video..!
 
airbuster
Posts: 321
Joined: Fri Mar 30, 2007 12:43 am

RE: What Atmospheric Conditions Cause This?

Wed Oct 30, 2013 10:56 am

What i believe happens is that with very moist/damp air being accelerated over the wing the temperature drops and cold air can hold less moisture than hot air, therefore you see a release of moisture over the wing.

Something like that.
FLY FOKKER JET LINE!
 
oly720man
Posts: 5771
Joined: Fri May 21, 2004 7:13 am

RE: What Atmospheric Conditions Cause This?

Wed Oct 30, 2013 11:31 am

What you see is the expansion of the air as it accelerates over the wing. As it expands the temperature decreases and if the temperature is reduced sufficiently, to the dew point or below, any water vapour in the air will condense and you'll see it as clouds over the wing.

When this happens will depend on the speed of the aircraft, the size of the aircraft (to some extent) and any manoeuvre g loading as well as atmospheric conditions.

Go fast enough


View Large View Medium
Click here for bigger photo!

Photo © Ben Wang



Pull some g


View Large View Medium
Click here for bigger photo!

Photo © Stuart Freer - Touchdown-aviation



Humidity and the dew point temperature relative to ambient temperature are the main atmospheric factors, though.

Judging by this, people are looking for a definitive answer.

http://www.aviationplatform.com/surv...ect%20over-wing%20condensation.pdf
wheat and dairy can screw up your brain
 
nomadd22
Posts: 1566
Joined: Fri Feb 22, 2008 7:42 pm

RE: What Atmospheric Conditions Cause This?

Wed Oct 30, 2013 11:33 am

Quoting airbuster (Reply 1):
What i believe happens is that with very moist/damp air being accelerated over the wing the temperature drops and cold air can hold less moisture than hot air, therefore you see a release of moisture over the wing.

Something like that.

You get less that ambient temperature and pressure on top of the wings so air at close to 100% humidity can't hold the water anymore.
Anon
 
User avatar
ZSOFN
Topic Author
Posts: 1380
Joined: Fri Jun 24, 2005 5:20 pm

RE: What Atmospheric Conditions Cause This?

Thu Oct 31, 2013 9:17 am

Quoting oly720man (Reply 2):
Humidity and the dew point temperature relative to ambient temperature are the main atmospheric factors, though.

Perfect - thanks! I knew the theory of why condensation occurs but I think that's the key piece of info above. Wasn't necessarily looking for exact ambient temperatures etc necessarily.

Who is online

Users browsing this forum: No registered users and 2 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos