OK, the figures are in the public domain. NATS income is circa £2.1 million per day and running costs circa £1.86 million per day, you can do the math :)
Not our job.
Nope, NATS operates on a licence from CAA (the goverment) and as a part of the conditions of it's licence must abide by rules, regulations and laws, including the ICAO guidance etc. which the government signed up to. Every ANSP in Europe operates similarly and, as you seem to have missed it, a lot of european ANSPs closed their airspace. Indeed some countries went further and banned all flying, but HM Government didn't take that step (and NATS don't have that remit).
Hhhmm, you must have missed NewsNight when Jeremy Paxman interviewed the new CEO. All the spokesmen on the TV etc were ATC facing senior managers (Alex Bristol Head of Strategy & Investment, Jonathan Astill Head of ATC Prestwick Centre, David Harrison formerly GM ATC Manchester now Head of Safety and so on) I think a member of the board wouldn't have quite the same street cred as a senior ATC manager.
No it's not a commercial decision, it's a safety decision. Pilots may only fly aircraft with a relevant air safety certificate, pilots may only fly aircraft for which they have a valid licence. This is done for many safety reasons but a big one is public safety. I wouldn't want some gung ho flyer leaping into the skies when it had been deemed potentially unsafe to do so and have the wreckage landing on my head thank you very much.

BD

I am amazed at the amount of people looking for heads to roll when all those heads did was follow the rules. Nobody can say any different .. Yes you may feel that the rules were over the top and that may well be , but herd ( or CEO opinion ) in itself should never be responsible for the convenient ignoring or sidestepping/ bulldozing of those rules. Neither should a 6th form physics experiment. I am sure there was a tremendous amount of work for the engine manufacturers to do in order to change their position and explicit rules in regards to volcanic ash.

I am relieved that things seem to be settling down now as my own company has been suffered some serious economic damage in the six days and the medium term damage we are unable to quantify at this time, still though at least we can now operate again.

Just to show what we are talking about here is an actual volcanic ash advisory from pilot departure documents:

Which references this message that may or may not be included in the paperwork:

You can actually figure out what it says if you guess a little - e.g. PSN must be positon since it is followed by a lat long but why are we still using decoder rings in this era of high speed internet and laser printers? A few more vowels, a little punctuation, graphics and some formatting sure would make this easier to read. I realize there are much better versions of this advisory available on web pages but often the terse teletype text is all that makes it to our paperwork. Of course, if something goes wrong, they'll have the full color graphics at the hearing.

Apologies for talking a little shop with this operational pilot stuff on the ash advisories.

Looks to be getting pretty active again in the past few hours, this morning it was only a very small amount of cloud around it. Third picture down

Link: Mulakot - myndavelar

Let the Great Experiment begin...
 

How can this be when the CAA's Revised Airspace Guidance last night requires airlines to:

· conduct their own risk assessment and develop operational procedures to address any remaining risks;
· put in place an intensive maintenance ash damage inspection before and after each flight; and
· report any ash related incidents to a reporting scheme run by the CAA?

Depends on the viewpoint; turbine bucket with ash sticking to it does not affect engine performance much. Replacing or scrubbing it might prove costly and time consuming.

Yes I did my "test" flight, thank you for asking.

Ever helpful ATC confirmed that my penetration of VA alert area was solely upon my discretion. I would have appreciated that even more, if they choose some earlier moment to tell me that than post-landing taxiing.

No, the engines did not flameout, stall, show glowing around intakes or props, spout fire from exhausts or increased their respective ITTs erratically & rapidly. There was no st Elmo's fire visible on the screen, it was noon anyway, and no strong sulfuric odour was present.

As I have made the post-flight written confirmation of the above mentioned facts, the maintenance stated that just flying through suspected VA contaminated area does not warrant complete post VA penetration maint procedure and cleared the machine for further flights.

At least now I won't get the bill if the overhaul comes before planned time.

Regarding see and avoid: in severe CAVOK one can discern layers of dirt in the atmosphere. Now I know what I've seen yesterday over mid Italy - it looked exactly as photo on the page 3 of German Falcon flight report. There was no practical way of going around this one, it stretched from the horizon to horizon. And I can tell that regarding my routing, Met office's prediction of VA spread was frighteningly correct.

are you saying they are not following the CAA guidelines ?

doesn't it say if an aircraft flies into a low ash density area that damage inspection has to occur after the flight ?

Met office report Northern Ireland 1400 BST — ash layer around 8500 ft, at least 500 ft thick - visibility greatly reduced with a strong sulphur smell.

Unconfirmed: Source BBC.

BBC reporting that pax from QF32 ( Heathrow - Singapore ) are contacting them. Flight is boarded but holding pax on the ground pending an improvement in the "air quality ". The skipper is telling pax that the ash concentration is above the levels in which Qantas are happy to fly.

No - we're not regulated by the UK CAA anyway and they did they homework; risk was assessed , procedures put in place after liaising with local CAA. Leading edges, props, engine intakes and transparencies were checked for abrasion damage or dust accumulation. None was found and acft was returned to service. Legal - yes, sufficient - couldn't say.

Clandestino - thanks for the clarification - makes sense.

btw I'm glad flight wasn't eventful for you.

A Tough Decision?
 

Rab-K - Your earlier post is twaddle. BA would not have just kept flying from day 1. After 5 days on FIR closure a DECISION needed to be made. Keep up the same position or open airspace. It's far easier to close it on safety grounds than open it on the same. But at some point a decision needed to be made. If WW helped get that one way or the other then good.

Inaction and hesitation are no more the friends of safety than knee-jerk, just do-it are. After 5 days and most EU FIR's starting to operate the UK was in danger of being the 'first ones in and the last ones out'.

And anyone who thinks that commercials are not heavily in play on all of this are much mistaken. No Buck, no Buck Rogers as they used to say in Flight Test.

As I said, I'd sooner have people who step up to the plate and make a decision than keep examining their naval fluff until someone else makes the decision for them.

We didn't go to the moon by waiting for the all clear from every quarter let alone getting to and from JFK. 'Decision height'. Captain Walsh called it.

HIAL update at 19:00 - airports closed until Thursday morning.

Volvo_Aero about Ash
 

Volvo-Aero has a short piece about ash in their jet engines, see the following url:
Actual - Actual : Volvo Aero
In princople they state that their engines can stand rain, ice and some birds, but not ash.

One can simply divide by the by-pass ratio of 4.3.

But there is the issue, under which conditions is the mass flow rate 1177 lb/s? We probably should consider a density figure at pressure and temperature corresponding to a typical cloud level. You can take standard atmosphere data etc.

However there is another estimate, based upon speed and diameter. Take the fan diameter, 74.1 in. Calculate the area. Divide my the by-pass ratio. If I do that, assume a speed of 180 m/s, for 0.3 g/m3, I end up with actually a very similar figure, 126 g/hour (assuming no algebraic error...) Of course one would hope crossing an ash zone would take less than an hour.

BTW, indeed the new threshold figure of 2 g/m3 comes across as not very conservative. I would have expected them to pick a figure more like 0.5?

A Danish perspective on detection ...
 

tolerance levels
 

In the UK MET charts posted by kyloe (#2186) the black area according to the label is the zone "that exeeds accepted manufacturer tolerance levels"

I´ll appreciate if somebody can give me the figure for that level.
¿some ash concentration? ¿An envelope for all turbines?

Here´s a link to new hi-res pictures of the Hornet engine published by the Finnish Air Force today:

Puolustusvoimat - Frsvarsmakten - The Finnish Defence Forces

Like has already been said, no significant damage was found, only "concentrations of foreign materials", partly melted, but it´s plain to see that these spots do not even come close to blocking any of the cooling holes in the turbine blades. On the other hand, the occurrence took place in the morning of the 15th, before any restrictions even had been put in place.

paidworker
 

I almost wrote, "Surely not the Nuremburg defence", but decided against. Instead may I refer you to the following quote:


Actually I think it was Douglas Bader!

As others have pointed out, there was obviously a problem with the rules. There is never zero volcanic ash in the atmosphere. We have always coped around the world until an invisible plume hit the UK. Thank heavens we have leaders like Captain Willie Walsh to sort things out.

Regards

S:)

Forecast models and charts fairly consistent on a gradual change to southerly winds, at least over the UK, overnight Friday/Saturday,

UKMO surface charts to T+120
Metbrief - Met Office Analysis and Synoptic Weather Forecast Charts via Wetterzentrale

300mb forecast charts to T+120 (rh side of page)
CRWS Jet Stream Forecast Map Menu

Here's hoping those lows approaching from the SW are more vigorous than forecast.