Ice fog video

[vaqueroaero]

A while ago someone posted a video clip of a 212 (?) doing some sling work somewhere very cold. As he picked up the load and flew away ice fog formed in the downwash.

Anyone got a copy/link to it? I can't find it.

Thanks in advance for any help!

[rotorrookie]

It was 205 making the fog... here u gohttp://s97.photobucket.com/albums/l240/flyboygms/?action=view&current=205FuelHaul2004-40C.flv

[vaqueroaero]

You're a gentleman and a scholar!

Thanks very much.

[rotornut]

Worth watching just for the sound!

[Aesir]

Yes love the sound.

[albatross]

Very nice indeed - thanks for that.:ok:

[detgnome]

Well there's something I've never seen before. Something to do with a cold and moist atmosphere - anyone care to expand?

[detgnome]

I'm sure the mixing is a factor (having caused fog by my downwash before!), but as the cloud is forming directly from the rotor disc, I'm guessing that the pressure changes caused by the rotation of the aerofoil sections may be condensing (possibly even deposition?) the water.

[detgnome]

The blades will be at a significantly higher pitch angle as it departs (with load), increasing both pressure changes and downwash.

[Matthew Parsons]

We're probably going to deep. The air is cold. The air coming down from the helicopter is full of moisture and condensation nuclei. Ice fog forms.

The main reason why ice fog forms from water vapour created by human activities, is because when its cold enough for ice fog to form there is hardly any water in the air. Survival in arctic conditions has the same hydration concerns as desert survival.

The helicopter's engines produce the water vapour based on how much fuel is being used, or how high the power demand is. It's hard to say for certain, but I think the helicopter is producing some ice fog on approach to the area, but doesn't produce a large amount until it tries to lift the slung load. Condensation nuclei are readily available from the exhaust.

One clue that there is some ice fog already is the "light pillar" is commonly associated with ice fog, however this could also be a lens effect.


We've spent the last week with temperatures below -30C and with Wind Corrected Temperatures of less than -40C (occasionally below -50C). I drove to work in ice fog that reduced visibility well below 100m at times (I know this because I couldn't see the traffic lights when I was first one stopped at the intersection).

Today we're up to -22C and my 6 and 8 year old are keen to spend the whole day snowboarding. You get used to it.


Matthew.

[HeliDriverNZ]

This Video is of a guy I worked with in the Yukon taken last winter they are in a TransNorth 205 doing a fuel haul into a lead/zinc project at a place called Wolverine lake about 100 miles east of Whitehorse, As the day worn on they noticed the effect comming off the blades and the one you see is the best shot they got all day. Apparently the ground crew hated going and hooking the loads on :)