Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Ash clouds threaten air traffic

Wikiposts
Search
Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Ash clouds threaten air traffic

Thread Tools
 
Search this Thread
 
Old 21st May 2010, 13:39
  #2961 (permalink)  
 
Join Date: Jan 2004
Location: london,uk
Posts: 735
Received 4 Likes on 4 Posts
What better risk analysis can you have than 50 years of records and millions of flights?

The undisputable facts are that NO ONE has been killed in the whole history of aviation by ASH.
What a very strange thing to come out with. You could use the same logic with Concord; it had a perfect safety record, until it didn't.

Maybe its becuase aircraft have always avoided flying through dust, certainly when they do, in certain concentrations its got very very expensive and dangerous. And VA is not the same from all eruptions, some, like this, are far more damaging.
peter we is offline  
Old 21st May 2010, 15:22
  #2962 (permalink)  
 
Join Date: Jun 2009
Location: VA, USA
Age: 58
Posts: 578
Received 0 Likes on 0 Posts
Yet more earthquake activity at Katla

Another quake directly under Katla of 0.9 magnitude at a shallower depth 4.8km.

A bunch under Eyjafjallajokull.

-GY

Last edited by GarageYears; 21st May 2010 at 16:06. Reason: Updated depth to Iceland MET office update
GarageYears is offline  
Old 21st May 2010, 15:35
  #2963 (permalink)  
 
Join Date: Mar 2002
Location: Florida
Posts: 4,569
Likes: 0
Received 1 Like on 1 Post
What better risk analysis can you have than 50 years of records and millions of flights?

The undisputable facts are that NO ONE has been killed in the whole history of aviation by ASH.

You are trying to do a risk analysis on something which to date statistically has shown NOT to be a risk.
Flight safety risk analysis does not work with extremely rare consequences.

What is done is to review much more common outcomes which fortunately for the passenger and crew are measurable degradation in safety (all nicely tided up in the definitions under 25.1309 and the Industry wide CAAM report published by the FAA.

Therfore even sucessful outcomes (the plane landed safely and the passengers changed their underwear) become part of the data. And nobody takes credit for events where nothing happened in millions and millions of hours but instead simply looks at the statistical probability that "any" degradation of safety (according to measured definitions) may happen that contains Volcanic Ash as an ingredient.

I keep saying that the volcanic conditions that we speak of today "will" result in some measurable degradation of safety but no more than the typical risk that we operate within everyday for all other causes (risk is never zero but it is managed within acceptable limits)

Most readers have no idea of what risk is allowed to underly each and every flight and the variable contributions of the causal factors versus time. Just because you identify a newly recognized causal factor "du jour" doesn't mean that you have to manage it to zero to justify to keep flying.
lomapaseo is offline  
Old 21st May 2010, 17:13
  #2964 (permalink)  
 
Join Date: Jan 2008
Location: uk
Posts: 857
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by peter we
And VA is not the same from all eruptions, some, like this, are far more damaging.
How much damage has this one actually done ? So far no one seems to have any confirmed damage.

Or do you mean that the response to the ash cloud was far more damaging (to the tune of a couple of billion) ?
infrequentflyer789 is offline  
Old 21st May 2010, 17:27
  #2965 (permalink)  
 
Join Date: Apr 2002
Location: Put out to graze
Age: 64
Posts: 1,046
Likes: 0
Received 1 Like on 1 Post
an F-18's engine is like a ramjet when compared to todays hi-bypass engines; no wonder it picked up a load of VA!
kick the tires is offline  
Old 21st May 2010, 19:49
  #2966 (permalink)  
 
Join Date: Aug 1998
Location: UK
Posts: 105
Likes: 0
Received 0 Likes on 0 Posts
Precisely ! The F18s would have been manoeuvring at high speed, high thrust, with no engine bleed worth speaking of, and probably at medium/low level. Under these circumstances they would have almost inevitably been damaged by ash ingestion.
Your average high-bypass commercial turbofan, on the other hand, operates at lower speed and relatively constant thrust, with air bleed. Our manuals tell us that in the event of an ash encounter we reduce speed and increase air bleed (and get the hell out of there).
The British government and authorities at the time of the original ash closure also mentioned an RAF Typhoon that had allegedly been damaged by ash. No doubt that was also manoeuvring at high thrust, low level, which bears no resemblance to the civil jet environment.
jshg is offline  
Old 21st May 2010, 20:42
  #2967 (permalink)  
 
Join Date: Aug 2002
Location: Europe
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Seismic activity has increased in the last few hours

Frequent but weak tremors in the area around our beloved Volcano in the last few hours, extending also to the proximity of Katla. Hopefully I am just over reacting and it does not mean anything at all.
The increase in seismic activity is objectively a fact in the last few hours but it seems normal activity intensity-wise, the location instead is a bit more worrying as epicentres seem to be moving towards Katla crater, but it could mean nothing, hopefully
ILS27LEFT is offline  
Old 21st May 2010, 22:47
  #2968 (permalink)  
 
Join Date: Jan 2008
Location: uk
Posts: 857
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by PBL
The "refutation" and "lack of re-refutation" have no more status than the original rumor. For hobbyists, this might be enough. For many professional purposes, it does not suffice.

PBL
This looks to be an official note on the incident - I think someone already posted it ealier:

CEN10RA135 Note the date of the incident - it's pre iceland VA.

I doubt there have been two uncontained failures like this on the same type in less than three months (or rather, if there had I think it would have been bigger news and we'd know).

PBL: From this incident note and your professional contacts you may be able to confirm the details and tie in the photos - in which case the date and location rules out VA.

This may be as close as the rest of us amateurs get to an official statement (reported statement form Cessna): Engine Damage Not Caused by Volcanic Ash: AINonline.
infrequentflyer789 is offline  
Old 21st May 2010, 23:10
  #2969 (permalink)  
 
Join Date: Jul 2005
Location: Up North
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Latest update from the Iceland Met Office and Institute of Earth Sciences indicates that the explosive activity has died down considerably.

Articles < Seismicity < Icelandic Meteorological office

topper3 is offline  
Old 21st May 2010, 23:17
  #2970 (permalink)  
Gender Faculty Specialist
 
Join Date: Mar 2002
Location: Stop being so stupid, it's Sean's turn
Posts: 1,882
Received 5 Likes on 4 Posts
at high thrust, low level, which bears no resemblance to the civil jet environment
Well except take offs, up to 10 a day for some of our aircraft, and go arounds.

And how can you say "no doubt" at low altitude and high thrust?
Chesty Morgan is online now  
Old 22nd May 2010, 01:38
  #2971 (permalink)  
 
Join Date: Jan 2001
Location: In the boot of my car!
Posts: 5,982
Likes: 0
Received 0 Likes on 0 Posts
I keep saying that the volcanic conditions that we speak of today "will" result in some measurable degradation of safety but no more than the typical risk that we operate within everyday for all other causes (risk is never zero but it is managed within acceptable limits)

Most readers have no idea of what risk is allowed to underly each and every flight and the variable contributions of the causal factors versus time. Just because you identify a newly recognized causal factor "du jour" doesn't mean that you have to manage it to zero to justify to keep flying.
Lomapaseo

This is a well written and thought If you want zero risk DONT Fly.

There are far more PROVEN risky elements to flight than Ash yet ASH has cought the public imagination hyped by the media amd reacted to by a whole host of back watching Burocrats and quangos.

We have had many fatal landing and takeoff accidents in strong winds and shear conditions even within the "accepted operational levels" but do we have a long thread like this one demanding all takeoffs and landings should only be with zero wind?

Ash which has NO fatality record throughout aviation history has been hyped into a monster or bad wolf which is out to get you.

Maybe its becuase aircraft have always avoided flying through dust, certainly when they do, in certain concentrations its got very very expensive and dangerous. And VA is not the same from all eruptions, some, like this, are far more damaging.
Peter We

Volcanic eruptions are nothing new. Jet aircraft 20+ years ago had hardly any sophisticated equiptment and NO fancy computer generated Ash Prediction charts.

Maybe they flew through low level ash concentrations and never knew about it. If you cannot see it it wont hurt you.

Volcanic Ash really isnt a new phenomina!

Our MEDIA HYPE driven, paranoid, liability and blame culture IS!!!

Oh well off to bed so I can dream of shooting and killing a few million birds to save us from Bird flu!

but more likely to save us from ingesting them in our jet engines a real ignored threat.

Pace

Last edited by Pace; 22nd May 2010 at 06:42.
Pace is offline  
Old 22nd May 2010, 06:16
  #2972 (permalink)  
PBL
 
Join Date: Sep 2000
Location: Bielefeld, Germany
Posts: 955
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by if789
This looks to be an official note on the incident - I think someone already posted it ealier:

CEN10RA135
Thanks, IF! Yes, brother forget posted it earlier, along with a quote, and I missed it (the quote distracted me).

The pictures show an aircraft with a D-reg (can't see other letters), with engine, rear fuselage and tail markings identical to those on pictures on the WWW of some other Citations from Eisele Flugdienst. So I can call up the BFU, or indeed the company, and find out.

PBL
PBL is offline  
Old 22nd May 2010, 09:18
  #2973 (permalink)  
 
Join Date: Jun 2008
Location: UK
Posts: 98
Likes: 0
Received 0 Likes on 0 Posts
I guess that a whole lot of the 'Ash Emergency' reporting from the Meeja generally is examples of 'Never let a Few Facts get in the way of a Good Story'.

Even the Flightglobal story reporting no significant damage to the F-18 engines, with a by-line of 23/4/10 was followed the very next day in the same magazine with 'Europe's volcanic ash response: was it adequate?' which mentioned the original 'reported' F-18 damage but not, strangely enough , the previous day's 'no damage' story. I haven't ploughed through the literally 100s of VA references just in Flightglobal to try to judge their attempts to balance what was published but my guess is that they were also to some degree cheerleaders on the 'High VA risk - We're all gonna die' bandwagon. Given Flightglobal's position as an industry-specialist publication and particularly its own masthead (Serious about Aviation), this is disappointing.

It would be a bit of a stretch to envisage a conspiracy in which someone hijacked the NTSB website and planted a faked-up story about the Citation CJ incident so as to place it well before VA became an issue!!!
brooksjg is offline  
Old 22nd May 2010, 09:44
  #2974 (permalink)  
 
Join Date: Jan 2001
Location: In the boot of my car!
Posts: 5,982
Likes: 0
Received 0 Likes on 0 Posts
BrookSJG

That is the sickening thing with the media they create the story they want and either ignore the facts or worse falsely make one thing appear to be another.

There are people who have had their lives ruined by the media by pretending something is true and painting a false picture to influence readers into believing it is true. Some of these people have been accused of horrendous crimes. When the courts find them not guilty that report gets a half inch column in the depths of the media report.

It is the same with this charade very damaging to aviation and made up of selective and false reporting designed to generate unfounded fear in the public.

These people including a select few in this forum should be ashamed of themselves as all they achieve is damaging an industry and peoples livelyhoods by their false representations. Worst is most dont even know what they are talking about.

Pace
Pace is offline  
Old 22nd May 2010, 10:15
  #2975 (permalink)  
 
Join Date: Nov 2007
Location: Oz
Age: 63
Posts: 84
Likes: 0
Received 0 Likes on 0 Posts
Interesting to see the nature of this ash, note the chunky structure.

Eyjafjallajökull ash under a petrographic microscope in crossed-polarized light at ~40x. Image by Erik Klemetti.



Eyjafjallajökull ash under a petrographic microscope in crossed-polarized light at ~100x. Image by Erik Klemetti.





tea & bikkies is offline  
Old 23rd May 2010, 17:34
  #2976 (permalink)  
 
Join Date: May 2003
Location: UK
Posts: 109
Likes: 0
Received 0 Likes on 0 Posts
Icelandic Met Office reporting marked decrease in activity:
The eruption activity is minimal and therefore no significant ashfall is expected. The volcano is still being monitored and an ashfall forecast will be issued if neccessary.
Visibly very different!
BillS is offline  
Old 24th May 2010, 00:07
  #2977 (permalink)  
 
Join Date: Jun 2008
Location: UK
Posts: 98
Likes: 0
Received 0 Likes on 0 Posts
VA forecast accuracy

Now that the dust has settled (at least for the moment!), has anyone seen any proper explanation (especially from the Met Office) for the overall lack of accuracy of VA Forecasting and, in particular, for the error(s) that led to the sudden and very obvious revision between 0600 and 1200 last Monday (17th May)?

Quite apart from the disruption caused by lack of inbound flights to LGW and other short-term problems, there was also a potential risk (already mentioned above) from reassignment of certain areas of the North Sea from 'white' to Black in the same revision.

Superficially, it looked like inaccuracies in weather forecasting had been allowed to 'bleed through' into the VA Forecast, with no later corrections being applied as real weather data superseded the forecasts. I have no actual evidence of this but unless something like this occurred, how could such a major restatement of the position of the ash cloud ever be required? - unless, of course, there were other problems with the model that only came to light over the weekend 15/16th May.
brooksjg is offline  
Old 24th May 2010, 06:25
  #2978 (permalink)  
 
Join Date: Apr 2010
Location: u
Age: 46
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
BillS

No, visibly is exactly what the report is saying... there is visibly only steam production, and other signs show that the eruption calmed down... How long, it's impossible to know, though. You can hardly see it on the cameras. Let's hope this is it!
lurkinginSTO is offline  
Old 24th May 2010, 09:07
  #2979 (permalink)  
 
Join Date: Jan 2004
Location: london,uk
Posts: 735
Received 4 Likes on 4 Posts
I have no actual evidence of this but unless something like this occurred, how could such a major restatement of the position of the ash cloud ever be required? - unless, of course, there were other problems with the model that only came to light over the weekend 15/16th May.
There was nothing wrong with the model or the forecasting, they were obviously told to change it, by the new government, to allow the airports to open.
peter we is offline  
Old 24th May 2010, 10:43
  #2980 (permalink)  
 
Join Date: Jun 2008
Location: UK
Posts: 98
Likes: 0
Received 0 Likes on 0 Posts
There was nothing wrong with the model or the forecasting, they were obviously told to change it
errrr....

The Powers That Be can (easily) change the specified minima/maxima for any given situation, so long as the new value remains inside other legal / regulatory limits that may apply. They already did this - by going from 2000 to 4000 micrograms/cube (with additional caveats). They did not need to get the VA forecast 'adjusted' as well. IMHO it would have been extremely foolhardy to even try to do so: someone could easily have other, more accurate evidence and/or might want to saddle the originator of the request/order with all the responsibility (and potential blame). In this situation, a leak to the media would be a virtual certainty! For a recent example of this, see Climate Change 'emails scandal' at the University of East Anglia. A bit of tinkering with climate data and months later, after an external enquiry and at least one Severely Career-Limiting Move, they're still chipping brown solids off the fans! Especially with this recent example to learn from, I'm surprised the Met Office has so far failed to come clean about the forecast!

So why were the limits and the VA forecast both adjusted, at very similar times?? (I still favour cock-up over conspiracy but have no better information myself.)

That said, it's also quite entertaining to watch the various regulators' heads popping above / below the parapet, depending on whether they reckon they'll catch blame (or have to take responsibility!) if ultimately something goes legs-up.

Last edited by brooksjg; 24th May 2010 at 11:19.
brooksjg is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.