Dan wrote:
And I was probably “unlucky”, but never witnessed any of the stuff described in this very thread.
Maybe. Or in the right place. VA mostly is not dangerous if you are in visual conditions and can see the volcano miles and miles away. If VA is around, I’d expect quite a bit of a reduction in visibility, like a brownish haze. Add to that in our case a noticable smell.
That is what it looked like when we flew in 2010. It was pretty much like in haze, but the colour was different and one could smell it too.
A quick check of my logbook shows 102 movements (1 landing + 1 takeoff) @ CTA, and 97 @ PMO, in very different conditions, over the course of some 20 years. Add to that a few circling Mr Stromboli, transiting or overnighting different strips in Sicily.
Some of them flights performed whilst Mr Etna was emitting visible smoke (and ash sometimes), with VA notams on, and off.
Believe half of what you see and nothing of what you hear 
And I was probably “unlucky”, but never witnessed any of the stuff described in this very thread.
Dan wrote:
Simply put, how can ash get toasted, melting… again?
That is exactly what happened to the BA747’s engines. The ash particles glazed the whole turbine wheels with thick residue.
The fighter airplanes who flew somewhere in Scandinavia during the event also had lots of residue.
It wasn’t a visible cloud. More like a cloud of heavy large droplets. Quite sticky too – covered the camera faceplate quite well, as the video shows.
I did wonder if it wasn’t some chemical emission – Italy is covered in chemical factories.
The cockpit air comes from outside but via convoluted routes.
I was thinking the same as @arj1…
like somebody was chucking bits of food at the exhaust system, etc, and these got toasted on impact.
That doesn’t really fit my perception of „semi permanent cloud of volcanic ash around Sicily“.
Simply put, how can ash get toasted, melting… again?
TB20 the vacuum system air is drawn from the cockpit
And the air drawn from the cockpit is coming from… let me guess… outside?
dublinpilot wrote:
Is there such a thing a cheap (perhaps disposable) volcanic ash detector that could be used in flight?
I don’t think there is, nothing official anyway.
However, I wonder. During the islandic volcano crisis, we were repeatedly asked to provide “proof” to the press that the ash was there, even though it was visible to the educated eye and we had it on the LIDAR stations which were in use then. Until one guy had a brilliant idea and called the phenology department. And yes, they had a measuring station up a rather high mountian. Two phonecalls later, we got the pic (need to ask if it is still someplace) of the station’s pollen catcher: It was totally dark brown. That pic went on the national news that night and stopped all discussions in Switzerland about the authenticity of the threat.
So I wonder: How about putting a strip of double sided sticky tape someplace in the airflow and look at it after the flight. I’d say,someplace near but not directly on the engine inlet. And obviously somewhere it won’t do damage if it becomes loose and flies off.
What that would do is most definitly catch any volcanic ash or other dirt in the atmosphere. VA is very easy to identify by color and smell.
Update after an Annual:
Instrument filters were clean. However in the TB20 the vacuum system air is drawn from the cockpit, not from the engine section. I am sure these filters are a big con; experience from many years ago suggests they are good for 10-20 years.
Landing gear was OK too, but this was retracted for most of that flight.
Quite a bit of muck inside the engine compartment – like somebody was chucking bits of food at the exhaust system, etc, and these got toasted on impact. Took a bit of cleaning but looks OK now especially after ACF50
The regulator was damaged beyond repair, as they said as a consequence of the alternator not working properly
I don’t buy that – it makes no sense electrically. The most current which the regulator will ever pass is the field current, and it needs to handle that at a 100% duty cycle.
Was the regulator ventilated with outside air?
Is there such a thing a cheap (perhaps disposable) volcanic ash detector that could be used in flight?
Never heard of one. All the kit seems quite complicated. I saw a BAE146 plane fitted out with a load of it.
Is there such a thing a cheap (perhaps disposable) volcanic ash detector that could be used in flight?
