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Ash clouds threaten air traffic

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Ash clouds threaten air traffic

Old 30th Apr 2010, 17:53
  #2461 (permalink)  
 
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Oh, and let's see if there is a spike in engine maintenance over the next 6 months. Time to look at GE, PW and RR stocks.
GarageYears

If there is a spike in engine maintenance then thats not our concern or business!

No one has questioned the fact that ash can damage engines. So can Birds, Hailstones, sand, ice.

As stated Ash has not killed anyone even in severe dense levels. That does not mean that at some time in the future it may happen but it has not yet.

I stand by my statement that this was not a scientific study of ash encounters so while the encounter MAY have been the one which caused the damage or was even Likely to have been the encounter which caused damage there is supposition and supposition is not scientific.

There is risk in anything and it is your choice whether you even step on an aircraft.

Do I personally think the authorities over reacted at huge expense to the aviation industry then my answer is a resounding yes and driven by the media.
There is nothing new there as we have had so many media driven scares in other fields of science which have cost a fortune and have ended up as nothing that it makes for scepticism especially as it effects our industry and our livelyhoods.

Pace
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Old 30th Apr 2010, 18:03
  #2462 (permalink)  
 
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The NASA DC-8 incident

GarageYears,

The NASA DC-8 incident has been cited in this thread several times.

Allow me to quote from the official report, which can be downloaded here

Top of page 11:
The flight crew noted no change in cockpit readings, no St. Elmo’s fire, no odor or smoke, and no
change in engine instruments. They did notice that no stars were visible, but this is typical of flight
through high cirrus clouds. After seven minutes the crew noticed that the stars had reappeared, and at about this time the
scientists reported that the research instrument readings had returned to normal. There was still no change
in engine or airplane instrument readings.
So, this was a flight at night through an ash cloud that was so thick that it was able to obscure the stars. Conclusion: this ash cloud would have been easily distinguishable by daylight VMC.

The research instrument readings returned to normal as soon as the stars had reappeared. This would suggest to me that no visible ashes, also means that no significant ash concentrations are likely to be present or even measurable.

This incident further shows that even flying through an ash cloud so thick that it can obscure the stars did not cause anything catastrophic to happen to the flight. (apart from the bill afterwards)

So allow me to use to use this incident to reinforce my ideas that keeping a flight clear of any visible ash concentration will keep the flight safe.

Therefore closing the entire airspace at is was done was a terrible overreaction.

Best regards,
Sabenaboy
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Old 30th Apr 2010, 18:52
  #2463 (permalink)  
 
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Would you have betted the lives of tens of thousands of fare paying passengers, as well as the financial health of six dozen airlines on this wild assumption before you had any scientific info upon which to base your decision?
Here's what I said on april 18th in my post nr. 819:
I live here about 50 NM west of Brussels. The weather here is great: absolutely cloudless, blue sky with almost unlimited visibility. Give me an A320 and I'll be glad to make a test flight in this airspace at any altitude between MSL and FL390. Yes, I'll even take my kids along on the flight, but I will stay clear of ALL visible ash clouds.
So yes, I would have "betted" my own life and that of my fare paying passengers in the conditions mentioned op april 18th! Sometimes using common sense is more useful then NON-EXISTING scientific facts! May I remind you that there has NEVER been an ash encounter flight incident unless in VISIBLE ash clouds!

Congrats on your worthless gift of 20/20 hindsight.
No hindsight! that's what I said from the beginning!

Acceptable concentrations of ash (according to Flight International) are 10exp-17g/cuM
I'm not so good with figures anymore, but this post nr 2477 appears to be a good reply to your figures.

Allow me to be just as disrespectful to your ideas as you were to mine by using the same smiley:

Last edited by sabenaboy; 30th Apr 2010 at 19:16. Reason: Added answer to the "hindsight" remark
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Old 30th Apr 2010, 19:17
  #2464 (permalink)  
 
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However, the NASA flight crew mistook the ash cloud for cirrus. As stated elsewhere, ash particles coated with moisture(ice) would look similar to cirrus. Ash embedded in cloud would also be a potential problem, so day VFR would seem to be OK.
What is the plan for when Katla blows?
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Old 30th Apr 2010, 19:22
  #2465 (permalink)  
 
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Get a sense of proportion please
Sorry but that made my day. We had a sense of proportion when it was suggested that millions of birds were slaughtered to protect us from bird flu!
The science
We bought £2 billion worth of Tamiflu as the science predicted 65000 deaths
(346 the actual number) with the recent mexican flu.

It is our LACK of proportion in this media Hype reactive society and our run by committee and quango everything ( No one ever built a statue of a committee) and where the airlines had to push for some sensibility and sense of proportion.

I repeat no one was ever killed in an aircraft by ash encounters even dense ash encounters.

I flew a business jet north to south uk hours before the airspace was closed, beautiful day, 100 mile vis at FL250, no cloud apart from broken cumulus way below.
When does flight international become the authority on what is acceptable ash or not?

Keep some proportion thats a good one

Problem we have is none of us will agree and this thread will keep going round and round in circles so best to beg to differ.

Pace
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Old 30th Apr 2010, 19:57
  #2466 (permalink)  
 
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That's what I always thought: stay clear of any visible ash concentration and there will be no immediate danger. Amazing how a simple misinterpretation of "zero tolerance" could lead to such a huge overreaction.
No, visibility was never part of the equations, that's your interpretation of it.
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Old 30th Apr 2010, 20:12
  #2467 (permalink)  
 
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We bought £2 billion worth of Tamiflu as the science predicted 65000 deaths (346 the actual number) with the recent mexican flu.
You picked the £2billion figure out of the air; its bullshit as Tamiflu doesn't cost that much and Pandemic flu is an on-going threat and the UK has a agreement to re-process the stock of Tamiflu as they expire. Flu pandemic last several years, until the entire worlds population becuase immune from the particular strain, Have you suffered from Pig flue yet? no? then you probably will do in future, maybe in milder mutation or maybe in its more severe form which kill you. The first year of Spanish flu was mild, the second year killed tens of millions.

The UK has a contract that allowed the cancellation of the VACCINE, which they invoked, will it be necessary to keep this contract rolling. Just becuase the average idiot on the street thinks infection disease are inconsequential doesn't mean that they actually are.

"Pig flu was nothing, give me Ebola, I'm invincible.", after all, flu is exactly like the science of aircraft safety.
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Old 30th Apr 2010, 20:35
  #2468 (permalink)  
 
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Peter We

Have a read! There are plenty of other sources if you google them and dont like this one and sorry my mistake £1 billion

The 'false' pandemic: Drug firms cashed in on scare over swine flu, claims Euro health chief | Mail Online

Just an extract

Planners were told to get morgues ready for the sheer scale of deaths and there were warnings that the Army could be called in to prevent riots as people fought to obtain drugs.

But with fewer than 5,000 in England catching the disease last week and just 251 deaths overall, Dr Wodarg has branded the H1N1 outbreak as 'one of the greatest medical scandals of the century'.
Pace

Last edited by Pace; 30th Apr 2010 at 20:58.
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Old 30th Apr 2010, 20:36
  #2469 (permalink)  
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While the various handbag fights go on, I should perhaps explain that the purpose of my post #2485 was to gently nudge whomever that if we do NOT get our ducks in a row over this question, then when Katla blows, given the same classic North Atlantic pressure patterns being extant, the events of recent times will be just a walk in the park.
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Old 30th Apr 2010, 20:59
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But who do we nudge?

BOAC, do you think Willie Walsh may be the right one to nudge? Or do the nudging? Certainly the Icelandic scientists seem to be concerned about Katia as there have been portents of seismic events in the last few days. Who is making plans to measure and plot ash clouds so that European aviation can avoid concentrations? Anybody?
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Old 30th Apr 2010, 21:07
  #2471 (permalink)  
 
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that if we do NOT get our ducks in a row over this question
BOAC

That will be the next one DUCK FLU

Sorry couldnt resist
More serious note yes I agree that proper research needs to be done to get realistic levels on different ash types maybe even not just ash damage but other pollutants.
From that research new training procedures for pilots in identifying ash and handling the aircraft in ash polluted air.
Because the reality is none of us really know and even the new levels have been plucked out of the air.

Now off with my handbag

Pace
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Old 30th Apr 2010, 21:28
  #2472 (permalink)  
 
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Originally Posted by Agaricus bisporus View Post
Congrats on your worthless gift of 20/20 hindsight.
If we'd had the foresight to ask folks in areas where volcanoes are common, we'd have found different rules to what was applied in europe. Or maybe everywhere else is just unsafe and we know best, based on our once in a couple of centuries experience of VA...

Would you have betted the lives of tens of thousands of fare paying passengers,
You bet them anyway, by closing the airspace. Even aside the risk to folks stuck for a month without medication etc., many many thousands of others were diverted to road transport. At 30 times the fatality risk ppm. [and that is just road travel - before we even get into looking at ferries or people crossing the Channel in RIBs].

Media estimates were 1M pax stranded from the UK alone. If only 10% of those were repatriated by road then you have, statistically, caused multiple fatalities. Unless you have the science to prove flight was >30 times more dangerous than normal.
That science apparently wasn't available - so a decision was taken without it, to subject hundreds of thousands of pax to a known substantially increased risk of accident, through less safe modes of transport, in favour of avoiding an
unknown level of increased risk in the air, from a problem that has never caused an aircraft crash.

Even if the ash made flight ten times more risky than normal, that was still the wrong decision.

as well as the financial health of six dozen airlines
The airlines should have been allowed to do their own tests and risk assessments for their financial health. That's their job.

Shutdown cost esitmates for the airlines alone are around 100 times the repair cost of the NASA aircraft damage quoted above, per day. Did we see 100+ aircraft go tech each day for major engine repairs after flight was allowed through the ash ? Nope. Wrong decision on that basis as well.

Had we let the airlines take the financial risk decision, any cost (fly or no fly) would have been down to them. Instead, the (wrong) decision was forced on them, and they (rightly) want compensation as a result - which will be from us, the taxpayers, not from those in charge who will probably get a pay rise because the job of regulating aviation is so much harder than they thought before...

Acceptable concentrations of ash (according to Flight International) are 10exp-17g/cuM.
Not any more. 2000 ug/cuM is the safety limit, below 200 is no risk, 200-2000 is (paraphrased) fly on your own risk assessment. Allegedly, those limits are based on science, and themselves have a safety margin of several times below what the mfrs. have found to be dangerous.

So the new and (your quoted) old safety limits are a factor of about 10E14 different.

Now, to me at least, those figures are way too far apart to have both been arrived at without, as you say, "wild assumption before you had any scientific info upon which to base your decision".

So, which do you think is the "wild assumption" number and which is the one with scientific evidence... ?
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Old 30th Apr 2010, 23:31
  #2473 (permalink)  
 
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errrr...in the interests of accuracy...

The NASA report includes reference detection by on-board scientific instruments of 'volcanic ash' but only by inference - I read it to mean that they ACTUALLY detected sulphur dioxide, which is also normally present in VA clouds but does NOT give any idication of ash density.

The chosen route for the flight was specifically intended to run to the north of a KNOWN ash cloud. The location information (from London VAAC??) was incorrect and the cloud was further north than thought. The reason for the error was partly due to the satellite imagery showing 'ice' clouds (ie. cirrus) rather than ash because ash particles had acted as nuclei for ice formation - so the satellite really was looking at a form of cirrus. It seems that once an ash cloud is 'old' and / or reaches a certain height, ash particles WILL get ice-coated and therefore difficult to positively identify.

Accurate detection of ash particle densities and drift rates of VA clouds therefore still seems to be a problem in the absence of research aircraft flying through them or very near to them. Covering that sort of area is probably infeasible. Hence my suggestions that there should be a far greater focus on post-flight inspections of ALL aircraft in affected regions to give a backstop check on where the ash is and where it's going as well as confirming the safe condition of the aircraft itself.
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Old 1st May 2010, 01:10
  #2474 (permalink)  
 
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..."scientific"...

Pace

Interesting statement about the scientific “level” of the said NASA DC-8 ash encounter “paper”. While this paper originally is part of thousands of “studies” and “reports” on the NASA Technical Report Server (NTRS), it can now be found nearly “everywhere” for known reasons.

It seems, that your knowledge level and insight what scientific research work and analysis is really about is quite dim. While a pilot’s license puts you in the front seat of a complex and remarkable man-made machine, it unfortunately lacks the intellectual capabilities and skills of a profound Ph.D degree and experience in either engineering or natural sciences. The retroactive blaming of all aviation authorities, VAACs and its associated scientific advisors and risk management teams in order to follow the media mainstream is therefore a direct result of this lack of core knowledge.

Better work on the quality rather than quantity of your “publications”…


F.I.
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Old 1st May 2010, 05:23
  #2475 (permalink)  
 
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The retroactive blaming of all aviation authorities, VAACs and its associated scientific advisors and risk management teams in order to follow the media mainstream is therefore a direct result of this lack of core knowledge.
I am not a scientist or an engineer and dont have a clue how many thousands of studies or papers have been written on the subject.
you obviously are by your profile, so please enlighten us to how a zero tolerance of ash which has been in place for years can suddenly be thrown on the ash heap within days and replaced with new levels of acceptable ash.

Maybe the culmination of all this research happened to coincide with this vulcanic eruption in timely fashion??? But then I am sure you will know?

As to your arrogance maybe PPRuNe should have a requirement of holding a PH.D degree to post here?

I am not alone in my "views" and it will be intersting to see whether the airlines are happy to accept their losses or challenge the whole handling of the crisis to retrieve those losses through the courts as they claim they will! They must feel they have an arguement over how matters were handled?
It is not the individual skills or dedication of the cooks in question but probably too many of them spoiling the broth.

Pace

Last edited by Pace; 1st May 2010 at 07:12.
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Old 1st May 2010, 08:03
  #2476 (permalink)  
 
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All the ash in animation

This cumulative animation shows the ash cloud from April 15 up through this coming Monday or so. One can see that the cloud began to disperse at about the same time that the powers that be switched from meteorological criteria to financial criteria to set ash limits. One can also see that another big blob of ash is expected to sweep over the U.K. in the coming 48 hours or so. Strangely, I haven't read anything about it in the news.

http://api.met.no/weatherapi/volcani...type=image/gif
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Old 1st May 2010, 08:25
  #2477 (permalink)  
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Appreciate the link, AGA, but mine seems to 'hang' on 20 April at the moment. Certainly the route KEF-LGW looks like a challenge up to then

It is of note that in ground terms the deposits of ash particles in the south of England (Aviate 1138's 'pollen') did not amount to any more than a good dose of summer Saharan sand, if that enables a sensible comparison of risk?
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Old 1st May 2010, 12:26
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please enlighten us to how a zero tolerance of ash which has been in place for years can suddenly be thrown on the ash heap within days and replaced with new levels of acceptable ash.
you are reading way too much into the words.

In order to continue you need to define how you intrepreted zero tolerance.

From a safety of flight standpoint take a look at the FAA release posted here a couple of days back.

Here's a typical question from an operator to an OEM

1) Is it OK to fly into volcanic ash ? ......

ans: No

2) What do I do if I accidently fly into ash ?

ans: inspect your aircraft and engine systems and clean and replace as necessary

3) Why is it not OK to fly into ash?

Ans: because it may damage your engines or aircraft by plating out in the hot section of engines, blocking small holes with ash or eroding aircraft windscreens, and/or blades in an engine.

4) Is it unsafe to fly into ash?

ans: it might be if etc. etc.

5) How do I know if I have flown into ash?

ans: any of the following symptoms may occur etc. etc.

6) How much ash does it take to bring down an aircraft?

ans: Don't know, it has never happened when the following steps have been taken. etc. etc.

7) How do I avoid flying into volcanic ash?

ans: ask a meteoroligist

No where in the above is there a statement of zero tolerance and aviation has not operated in a zero tolerance regime but rather chosen the route of avoid with caution and accomodate if an inadvertent encounter occurs.
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Old 1st May 2010, 14:16
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Hello, I normally just read this forum (had to actually join to make this post)- they are often entertaining and sometimes enlightening, so thanks to all the contributors. My apologies if I don't do this quote thing in quite the correct manner.
With reference to BOAC's post

"Iceland’s Katla Volcano New Seismic Activity 4/28/10: Eruption Imminent Today, Iceland’s Katla volcano had a significant earthquake. Although no eruption has happened yet, this would be the normal course of events prior to an eruption. No official news story available at this time, but the seismograph data is available for public viewing here:

Icelandic Meteorological Office - Volcanic Eruption - Seismicity - Weather forecasts - Weather observations - Avalanches - Hydrology - Climatology - Sea Ice

Please can we have some opinions?
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Old 1st May 2010, 14:50
  #2480 (permalink)  
 
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lomapaseo

Your last post really 'hit the nail on the head' with respect to the difficulty operators faced during the inital few days of the ash cloud reaching the UK and Europe. Given that the industry had no quantitive measure as to safe levels of ash, as we now seem to have established, albeit in extremis- all our previous instructions and procedures instructed us to avoid ash- period. Is it a surprise to anyone that we stopped flying in the face of this ash cloud?- such as it was.

What operator would have/could have ignored VAAC advisories, Ops Manuals and OEM instructions, even if NATS would have issued clearances? None is my guess. And if and when Katla goes, if the UK is affected, I predict we'll have a similar difficulty in deciding if its 'safe' to operate. Unless the plume is very well definded, which it wasn't last time, quite how we'll flight plan around ash in a dymanic atmosphere is going to be another major issue.
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