Volcanic ash discussion here please!

To understand the severity of volcanic ash I've taken the 1st few lines from an aircraft maintenance manual for the inspection of an aircraft after a flight through the ash:

WARNING : DO NOT BREATHE VOLCANIC ASH. DO NOT GET VOLCANIC ASH IN YOUR EYES. PUT ON PROTECTIVE CLOTHES, EYE GOGGLES AND A RESPIRATOR MASK. MAKE SURE THAT THE RESPIRATOR MASK CAN REMOVE VOLCANIC ASH FROM THE AIR. VOLCANIC ASH CAN CAUSE EYE IRRITATION AND INJURY TO THE RESPIRATORY SYSTEM.
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(1) Volcanic ash
(a) Volcanic ash is hard, very abrasive and acid (pH between 2 and neutral). It can cause erosion/abrasion, etching or shot-peening on the surfaces and can remove the finishes/protection and thus cause damage/corrosion.
(b) The ash particles can be of different sizes but the texture of volcanic ash is almost the same as talcum powder and can enter all orifices and go through many seals. Volcanic ash will stay:
- on bare and lubricated surfaces.
- in all corners.
- in bottom places.
It can cause unusual wear and contamination of many aircraft systems and filter elements.
(c) The volcanic ash will melt when it goes through the combustion chamber of the engines.
The melted ash has very high adhesive qualities and bonds to engine parts and thus decreases engine performance. It may obstruct the fuel injectors and can cause an engine shutdown.
(2) Inspection requirements
(a) Volcanic ash can cause severe damage/contamination on the structure / systems of the aircraft.
It is not possible to estimate the quantity and the type of damage after volcanic ash contamination. Therefore, it is necessary to do a full inspection of the aircraft to know the damage and make a decision about the necessary repair/action.
(b) All the necessary inspections are visual unless the text gives other instructions.
Operators can refer to the Non-destructive Testing Manual (NTM) and use non-destructive procedures.
(c) If you find damage to the aircraft structure, refer to the Structural Repair Manual (SRM). The SRM has the approved damage limits and repair procedures.
(d) If you find damage to paint/protection, refer to the Structural Repair Manual (SRM). The SRM has the approved paint/protection repair procedures.
(e) Examine the aircraft surfaces, structures, systems for contamination, erosion/abrasion, dents, etching, delamination or other damage.

News reports over the weekend suggested that the IAA are conducting test flights into the plume. Are they and if so what aircraft are they using?

Pilots 'can navigate safely through volcanic ash'
By David Learmount

http://www.flightglobal.com/articles/2010/06/04/342814/pilots-can-navigate-safely-through-volcanic-ash.html


The aircraft-mounted passive infrared volcanic ash detector system called Avoid that is being tested by EasyJet and Airbus was developed some years ago by the Climate and Atmosphere Department of the Norwegian Institute for Air Research, but no-one took up the idea until now.
Dr Fred Prata of the institute says that being able to "see" the ash is the key to being able to navigate through it safely, because it is not distributed uniformly throughout the block of airspace downwind of the volcano that is producing it.
Prata explains: "I think it needs to be stressed that volcanic ash never fills the skies and there are always routes around the hazard. This is what happens in most parts of the world now, especially, Alaska, Japan and Indonesia, where airlines make quite large, costly diversions to avoid ash clouds forecast by models and observed from satellites. With Avoid fitted these diversions would be shorter, and more direct routes could be found."