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-   -   Ash clouds threaten air traffic (https://www.pprune.org/rumours-news/412103-ash-clouds-threaten-air-traffic.html)

peter we 17th May 2010 18:05


Ryanair claims the VAAC's forecasting is not only unreliable but "substantially fictitious".

"It would appear that there is one model for air safety for all other UK airports, but when it threatens the opening of Gatwick and Heathrow, these [forecasts] are simply ignored," it adds.

"Today's decision to re-open Gatwick and Heathrow airports, despite the fact that this imaginary black cloud or 'no-fly' zone is hovering right over Heathrow and Gatwick, proves that the [VAAC charting] no longer retains any credibility or confidence within the airline industry."
Ryanair demands more lenient ash-protection rules

Ryanair noticed it. Either the danger or the precaution is fiction....

oceancrosser 17th May 2010 18:12


Katla waking up?

--------------------------------------------------------------------------------
Just to add more fun... there was an earthquake below the Katla volcano within the last 12 hours. If Katla wakes up (which it surely will based on history) all the current fun and games will look like kiddy stuff.

There have been instances where Katla has erupted shortly after Eyjafjallajokull, but it is by no means a regularity. Such eruptions have tended to be on the smaller side. The indicated quake you referred to appears to be a fluke. It is shown at 200 meters above the surface and a quality (of measurement) index of 37%. This is unedited data and gets corrected all the time. Don´t read to much into it.

plane speak 17th May 2010 18:30

New rules
 
The CAA change the rules again.....press release:


Further progress made to safely minimise ash disruption

The UK Civil Aviation Authority (CAA) today reports a positive outcome from discussions with airlines, regulators, and aircraft and engine manufacturers resulting in new measures to reduce airspace closures caused by volcanic ash. These new measures will be available from midday tomorrow.

A new area of operations can now be introduced that creates a ‘Time Limited Zone (TLZ)’ between the black ‘No Fly Zone (NFZ)’ and the red ‘Enhanced Procedures Zone (EPZ)’. Aircraft and engine manufacturers, based on new research and analysis, have agreed that it is safe to allow operations in the new zone for a limited time at higher ash densities than is currently permitted.

To operate in the new zone airlines need to present the CAA with a safety case that includes the agreement of their aircraft and engine manufacturers. UK airline Flybe is the first to achieve this and will therefore be able to use the new zone from midday tomorrow.

This means that areas of our airspace that would have previously been closed can safely open, further minimising flight disruption.
Link here

topper3 17th May 2010 18:40

I think the depth at Katla was actually 9.5km with a magnitude of -0.2 (negative magnitude?) Makes no sense really.

slf99 17th May 2010 19:34

Flybe first to adopt CAA relaxed rules
 
Pity the Flybe e-mail I've just received (as sent to all its frequent flyers) is entitled "Flybe welcomes new CAA fules for Q400 flying".

Shurely some mistake, as any fule knoeth.... or perhaps not?

oceancrosser 17th May 2010 20:23

I have in front of me a report from 2005 by the very scientists that are currently studying this eruption. This is a risk assessment of probability of eruptions and subsequent flooding (which is the major threat). I have property on the outskirts of the most extreme flooding area.
I could post the article here, but it is in Icelandic so it is only of use to few people.
Eyjafjallajökull is known to have erupted 4 times in the last 1500 yrs (~500, ~920, 1612 and 1821. Katla is known (and estimated) to have erupted about 25 times since ~700 (this includes possible minor eruptions that never made it through the glacier). Of this number, 6 are considered to have been major. The interval between major eruptions 150-300 years. The last major one was in 1918.
Eyjafjallajokull and Katla have erupted at a similar time 3 times, but the only time it is known Katla was following was in 1823. It is apparently not documented which went first in ~920 and 1612.
So hold your southern horses for a while. Everything moves around here, and does so all the time. We are pretty used to it. I have watched and flown around about 8 eruption in my aviation life. We even used to do sightseeing flights around the eruption.
Prof.Haraldur Sigurdsson who was on 60 minutes recently, and is renowned around the world of volcanology considers this Katla angle "a media fever". Is that where you are from? Your profile certainly does not indicate that you are an aviation professional.

The thing is that this is the first sizeable eruption in this part of the world since the start of modern aviation. Todays aviation industry needs to learn (and fast) how to live with it, and get as close to normalcy as possible.

Oh and yes the eruption was spectacular to watch on Friday and Saturday this weekend from my country property, 30 miles from the crater.

GarageYears 17th May 2010 21:04

Oceancrosser, I certainly defer to your local knowledge, but I would also refer to a number of knowledgeable vulcanologists that I am in contact with. While their science seems to border on voo-doo at times, their consensus is that Katla is due and will likely "pop" (my words, not theirs) very shortly (qualified to mean somewhere within 0 to 2 years from right now). I guess time will reveal who is right.

I certainly hope you and your property remain safe, and I would add am quite envious of what are no doubt amazing views.

- GY

22 Degree Halo 17th May 2010 21:34

Better to be safe than sorry, huh?

SEVIRI BTD

Ends at the current day ^

petitb 17th May 2010 22:12

petitb
 
itsresidualmate.

"So far I've not found any evidence of ash damage in all the aircraft I've inspected (northern european regional routes). I've asked a lot of my colleagues in other airlines if they've found any evidence of ash damage or if they've heard of it being found :- Nothing. Not one engineer I've contacted has found or known of anyone finding damage. Now I don't claim to know every engineer in Europe, but it does seem that ash damage is thin on the ground (or the blades). I think that any maintenence cost saving from not flying is going to be dwarfed by the loss of revenue."

Would this by any chance be the result of not flying through ash, in other words the restrictions are working ?

sky9 18th May 2010 06:36

I would have thought some clever scientist would have come up with a double sided sticky patch that samples the actual dust flown through by the aircraft and records it for monitoring and analysis.

Genghis the Engineer 18th May 2010 07:05


Originally Posted by sky9 (Post 5700097)
I would have thought some clever scientist would have come up with a double sided sticky patch that samples the actual dust flown through by the aircraft and records it for monitoring and analysis.

Problem is, you'll get all the low level dust on the way up and down as well, which is always there.

G

BOAC 18th May 2010 07:10

Gengis - the key is in "and records it for monitoring and analysis." This dust/ash is, we are told, quite different to both 'normal' volcanic ash and, say, something like Saharan desert dust - surely it is possible to separate? Why is it not possible also to have a sampler which can be isolated until needed - a simple motorised door would do? This part of the world is going to have come up with something PDQ as it looks as if the problem is with us for a while.

Pace 18th May 2010 07:16

Acceptable Ash Levels Doubled
 
I see from today that the acceptable Ash levels have been doubled with the Airlines calling for a tripling of those levels.

Pick a number from 1 and 10 if it doesnt work start again :ugh:

All sounds very scientific

Pace

brooksjg 18th May 2010 07:24

As has already been discussed, aircraft already have air filters that (it is said) can be examined for VA particles - all you need is a microscope and possibly a very precise weighing machine. There's also oil from the engines, which is a very accurate tell-tale for larger volumes of nasties the engine might had through it since last oil-change. We've not heard much detail about what's actually being done with this existing evidence, however.

brooksjg 18th May 2010 07:34

VA Forecast accuracy
 
As it happened, I was paying closer attention to the Met Office Red/Black composite graphics yesterday and was surprised to see the supposed Ash Cloud with a large Black area extending southward nearly to LGW on the 0600 forecast suddenly retreat at the speed of light!! The new southern boundary then went only as far south as Central Scotland. I guess I should have only relied on the less-detailed the official VA advisories - these did NOT show any such sudden change!

Explanations for this came there none - how people who rely on this stuff for flight planning are supposed to make good decisions beats me!.

Just pre-announcement of yet another category of ash cloud flyable under yet more conditions, risk-assessments, etc.

Then, BBC Newsnight covered the topic of VA. Aha! I thought - now the UK public will get some clarity. Wrong. All we got was Susan Watts delivering a deeply-flawed piece (with an incorrectly labelled diagram of an engine) about the effects of VA.

itsresidualmate 18th May 2010 07:57

Petitb;

"

Would this by any chance be the result of not flying through ash, in other words the restrictions are working ?


I've got an elephant scaring crystal in my garden, it must work because I haven't seen any elephants in there!! :)
With the amount of civil air flights and the number of inspections we're doing I find it hard to believe that the threat is as real as the CAA/EASA/Government make out. Where's the evidence of contamination? Have no engineers found problems? To ground flights there must surely be a current danger to aircraft, I just don't believe there is. Of course flying through a volcanic plume will probably ruin your day, but flying around hundreds of miles away when it's dispersed? Maybe some accelerated wear and tear but the plane ain't going to fall out the sky!

http://www.wwiivehicles.com/usa/airc...esuvius-01.png

sabenaboy 18th May 2010 08:29

@itsresidualmate:

you wrote:

With the amount of civil air flights and the number of inspections we're doing I find it hard to believe that the threat is as real as the CAA/EASA/Government make out. Where's the evidence of contamination? Have no engineers found problems? To ground flights there must surely be a current danger to aircraft, I just don't believe there is. Of course flying through a volcanic plume will probably ruin your day, but flying around hundreds of miles away when it's dispersed? Maybe some accelerated wear and tear but the plane ain't going to fall out the sky!
I agree with you on this, itsresidualmate.

petitb wrote:

"So far I've not found any evidence of ash damage in all the aircraft I've inspected (northern european regional routes). I've asked a lot of my colleagues in other airlines if they've found any evidence of ash damage or if they've heard of it being found :- Nothing. Not one engineer I've contacted has found or known of anyone finding damage. Now I don't claim to know every engineer in Europe, but it does seem that ash damage is thin on the ground (or the blades). I think that any maintenence cost saving from not flying is going to be dwarfed by the loss of revenue."

Would this by any chance be the result of not flying through ash, in other words the restrictions are working ?
Even though I also believe that authorities have overreacted, I have to agree with petitb that the fact that no damage (or ash) has been found, proves absolutely nothing. Your argument does indeed resemble very much the elephant scaring crystal in our garden, I'm afraid.

As Pace has stated before: a better argument is that there's never been an incident outside of ash concentrations visible to the naked eye. (Or would have been visible in daylight VMC) (Anybody reading this: pls don't bring back the NASA DC8 case again:ugh: )

Best regards,
Sabenaboy

infrequentflyer789 18th May 2010 09:42


Originally Posted by brooksjg (Post 5700186)
As it happened, I was paying closer attention to the Met Office Red/Black composite graphics yesterday and was surprised to see the supposed Ash Cloud with a large Black area extending southward nearly to LGW on the 0600 forecast suddenly retreat at the speed of light!!

Explanations for this came there none .

Explanations in the press now:

The ash cloud that never was: Inaccurate Met Office forecast causes airport chaos for 50,000 | Mail Online


A CAA spokesman said: ‘The Met Office model was predicting ash which was not there when the test
flights were done. We have asked the Met Office why their forecast model showed something which
was not subsequently backed up.’
Not entirely sure why the CAA regard an inaccurate Met Office forecast as something out of the ordinary, but...

The second concern is that clearly if ash is not present where the forecast says it is, it may also actually be present where the forecast says it's not. I hope that at the pointy end, the presence of white on the charts is not being substituted for the mk1 eyeball and see and avoid.

MPN11 18th May 2010 09:54

Perhaps someone will regenerate an old concept to defeat long-term ash problems?

XC-99

Slow but safe? ;)

green granite 18th May 2010 11:30

What concerns me is if the computer model is inaccurate as it appears to have been in this case, could it get it wrong the opposite way round and end up with aircraft flying through an ash cloud not predicted.


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