Volcanic ash cloud/plume density

[sudden Winds]

Hi,

I am looking for anything that might have been published regarding density of a volcanic ash plume vs visibility. What I basically want to know is if there´s any way of approximating or estimating density based on forward visibility. Any contributions, personal experiences, urls, etc will be greatly appreciated.
Regards,
SW.

[John Farley]

sudden winds

You need to talk to Genghis the moderator on the flight test forum

[awblain]

I'm far from an expert on volcanic aerosols, but basing it on the opacity of interstellar dust, it's likely to be very complicated.

Smaller particles tend to scatter and absorb more light per unit mass of ash.
Fluffier - more snowflake-like and less-spherical - grains tend to scatter more light per unit mass.
Scattering and absorption properties will depend differently on wavelength, grain size, grain shape and grain material.

The ash might be associated with SO2? This also casts a brown haze that likely interferes with the signal from the solids. Ice mantles/coatings can also modify the optical properties of ash grains.

[irishpilot1990]

Would entry into an ash cloud be an immediate Mayday call?

With the possibility of duel engine failure would that make it a distress situation?

[lomapaseo]

Would entry into an ash cloud be an immediate Mayday call?

With the possibility of duel engine failure would that make it a distress situation?

There are other things to do first before you call the doctor.

Turn off AT, pull back on the thottles and turn.

Not much somebody on the ground is going to do for you. Then just aviate, navigate and then communicate

[Slasher]

Would entry into an ash cloud be an immediate Mayday call?

No. Serious **** hasn't happened yet. PAN call.

With the possibility of duel engine failure would that make it a distress situation?

See above reply.


If you DO get dual engine failure then serious **** has happened. Mayday call.