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TRANSATLANTIC No fly Zones
Can someone from an airline planning dept or ATC please explain what is going on to a confused SLF like myself.
In the last few days a number of transatlantic flights to and from Spain have been routing North South and vv across the UK going up towards 60 North no doubt to avoid the ash cloud. One day AA's MAD- JFK B767 was even reported as going over NE over Cherbourg, London and Ipswich before turning NW over the N Sea and then running parallel to the UK East Coast about 100 miles offshore. Also reported N-S or vv over the UK are transatlantic TAP flights and Aeromexico/ Mexicana flights from Madrid. At the same time most AF transatlantics, along with KL and LH (both ETOPS twins and 747s) seem to have been routing North just off the Noreweigan coast During all this disruption, a small number of transatlantic flights mostly BA have been reported as coming off the Ocean / going oceanic over Cork and Shannon. If the ash cloud area was stopping all these other flights going on their normal "best route", how come these flights seemed to come through the affected area.:confused: Any explanation gratefully received! Suzeman |
I would guess, altitude. Waiting at GRN yesterday for flight to leave, (and it was subsequently cancelled due to 'volcanic ash cloud' starting at FL20) we could hear and see trans-continental aircraft flying way overhead, where we live that's usually the Paris CdG to Africa run, obviously above the top level of the cloud at FL30.
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dublindispatch: Is 20000 some magic height that the industry has chosen or is it based on average ash height etc? Ifit can be convinced that this process is scientifically valid (which at the moment is not the case), 'the industry' would rather have charts with more and probably different altitude segments, to help them make their own operational (not commercial) judgement about whether to fly under, over or around. |
I posted earlier about bringing my parents home from MAN after their Thomson flight to Tenerife was indefinately delayed yesterday.
They were going on holiday with friends who were flying to Tenerife with Monarch from Gatwick, similar time yesterday. Guess what, they arrived in Tenerife 8pm last night. How? Did Monarch fly through the ash? I presume not. Also yesterday evening I looked at Manchester departures and flights from mid afternoon were showing as having left!! Am I being cynical in thinking Thomson may have used the plane my parents were due to fly on for another service. Anyway they are at the airport now due to depart at 20.50hrs tonight. 36hrs late. |
Don't think you're being overly cynical but all airlines are having different problems posed by the current conditions and are having to deal with their own particular disruption in their own way. It's not the airline trying to victimise your parents, or anyone elses for that matter, they're just trying to cope as best they can.
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I just just glanced at this...
Am I being cynical in thinking Thomson may have used the plane my parents were due to fly on for another service. .....because I saw a Thomson taking off from GRN about 12:00 local today, and can't remember having seen one there at that time before.... To be fair there's a lot of disruption and the airlines are doing their best. |
Just to add to question 1/ above, how long can you stay in the red for? briefly? can you hold in it? surely accumulative damage starts to play a part.. Not 100% sure but the red coloured area ( UK MET Office ) will mostlikely illustrate the so called Zone 2 while the black coloured is the Zone 1. Zone 1: Limited No-Fly Zone is an Area with a High Density Volcanic Ash Contamination. A "No fly zone" - which includes the main area/core of the volcanic fallout, with an additional buffer zone. Zone 2: Potential Contamination Zone is an Area with a Low Density Volcanic Ash Contamination. An area outside Zone 1 where flying can be conducted when actual conditions, risk assessment and test(s) can establish, that flights can be conducted at an acceptable level of safety and requires prior permission from the operators Authority. At least Icelandic AOC holders have to apply for such permission from the ICAA. Prior such an application you have to set up several operational & maintenance related procedures ( e.g. recommendations from the TC holders ). In addition to the daily checks i.a.w. EASA SIB No: 2010-17, the ICAA for example requires, when an aircraft has been operated for a maximum time of three accumulated flight hours in "Low density Ash" (Zone 2), an inspection in accordance with aircraft and engine manufacturer guidelines for inspection after flying in volcanic ash shall be performed. Not sure how other authorities are handling that and if they have these accumulated 3 hours restriction in place as well. However, GE for example says for Zone 2 ( greater than 2E-4 grams/meter cubed, but less than 2E-3 grams/meter cubed predicted zone, "Enhanced Procedures Zone" ): There are no additional maintenance or operational procedures required to ensure safe operation! RR and PW have a set up a little bit different recommendation. While the engine OEM's are not calling for any time limitations when flying thru Zone 2, the local authorities are handling that obviously different. So your question can't be answered with a "standard statement". BTW: the local TV station RUV made a nice video clip last evening from the local at eruption side: To see the clip, click on "Horfa á myndskeið"! Currently we have again massive ash fall in the south east and all the glory can be watched here : Also a good overview in regards to the actual seismicity( Eyjafjallajökull vulcano is at the glacier in the south ) can be found here: ( not sure if those links have been posted already ) Greetings from Iceland Sunny :) |
Zone 2 greater than 2E-4 grams/meter cubed, but less than 2E-3 grams/meter cubed Or 12 - 180g/min or 720 - 10,800g/hr Even though the great majority of that goes through the fan and not the core it won't take long to build up accretions if only a thousandth part of that gets to stick... |
Noticed this morning we have light gray/brown, slightly "fluffy" deposits on our windowsills here at 3ºE 42ºS. (Catalunia). Never seen this before. It is NOT the other usual bane of our lives here, dust from the sahara or spring pollen. Suspect it's ash but que saps ?
I just posted a photo of these deposits but on JB...... |
It's still a great mystery to me where the VA evidence is going!
Under present (new) rules, it would be very unusual for an engine to run for as long as an hour in an ash zone or around the edges where it can be assumed there would have to be some ingestion. Nevertheless, if the permitted worst case is 10 (TEN) kilos per hour through the front of the engine, there would have to be some traces left, somewhere, from shorter encounters. So where is it?? Or are people not yet looking in the right places? |
I suspect a lot of it is inside the turbine blades as commented by many and will make itself evident in due course with reduced engine life and the odd blade falling out of the back with an alarming banging noise?
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It's still a great mystery to me where the VA evidence is going! Under present (new) rules, it would be very unusual for an engine to run for as long as an hour in an ash zone or around the edges where it can be assumed there would have to be some ingestion. Nevertheless, if the permitted worst case is 10 (TEN) kilos per hour through the front of the engine, there would have to be some traces left, somewhere, from shorter encounters. So where is it?? Or are people not yet looking in the right places? Lots of data available to the big operators to put this in perspective so ask them. |
Recently boroscoping a Trent 800 in the sandpit and quite distinctive red sand particles adhering to leading edge of final stages of HP comp blades which dont seem to give problems , but would imagine anything else , i.e ash would possibly do the same .
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....not much accumulations are found within the engine. The coarse stuff hugs the outer walls and goes out the rear after slowly eroding blades. The fine stuff flows freely through the cooling holes and finally ends up out the rear of the engine. The in-between stuff either dirt or ash may get stuck in the cooling holes.... 1 - where there's enough VA (especially large particles) coming through the combustion chamber, getting hot enough to melt and coat the first stage blades and vanes with a layer of glass-like material, and therefore cause rapid blade failure and/or the engine actually stopping due to disruption of gas flows. No-one has yet identified (here, at least) a ball-park figure for ash density where this starts to be a possibility but it seems that it's going to be at least one, if not two, orders of magnitude greater than the current Black area average. 2 - where there's NOT enough VA melted inside the combustion chambers to permanently coat blades to a dangerous level and any VA that goes through the cooling system is fine enough to go through and not get stuck inside galleries or holes. From what has been discussed here, unless an engine has already been exposed to a lot of VA, any ash that does get into the cooling system will not go above its melting point (ie. the cooling system will still be doing its job!) and will therefore continue through the blade holes and slots, and out the back with relatively little effect. Given the nature of the current Iceland eruption, the VA particles will be very small (otherwise they wouldn't float around for so long). If / when the ice and water around the vents and leaking into the volcano has mostly gone, any VA particles still being formed will be much larger and will therefore fall to ground / sea much more quickly and become of little significance (eg.) above FL10 and /or more than 100 miles from Iceland. These (under-informed) conclusions are supported by the lack of published evidence of VA discovered inside engines during the current Iceland situation. There may of course be other evidence and other people who already know very different! |
UK Met charts show the FL0 - FL200 no go zone over the UK Monday, much of Germany could be out Mon/Tue and into Wed :eek::eek::eek:
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Where do you find that please SSK
Thanks |
Where do you find that please SSK Thanks |
Hope not due back from Koln on Tuesday morning!:\
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Which charts? I don't see any for monday on the met office website...
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Monday
Nor can I find any predictions for the beginning of the week, but I hear from a well placed insider whos says he heard from a reliable insider in an un-named UK based carrier that MON/TUE next week we may see the "black zone of doom" covering most of Northern UK and Irish airspace.
Comments please guys n gals? |
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