Mystic Met closed Europe with computer model

"Contingency Plan" Definition Required ...

I keep hearing talk - especially from the chaps at Nats that upon receiving news of the cloud they have implemented a "Contingency Plan".

What is their "Contingency Plan"? - It looks to me like the ability to say "Stop" when confronted with data, not generated by them, which is compared to a rule book issued by the European agency. Anybody could do that. They appear to have no executive authority, at all.

In my book, a "Contingency Plan" would include: Alerting Ferry companies to put on extra ship. Alerting coach and rail companies to put on extra vehicles and coaches. Contacting embassies abroad to implement previously agreed visa and travel waivers to ease the chaos abroad and alert UK "Border Agency" to expedite passage back into the country without petty -fogging beurocracy likely to try the patience of the most stalwart returning "rough sleeper" and family. A phone number to someone with real information instead of a time-serving jobs-worth would also not go amiss.

When this is all over there should be a complete clear-out of these hopeless Apparatchiks into some less demanding role.

Andrew Orlowski Comments and Ratings?

Damn I actually like the article...

TANJ

Outside their remit

The MET only has a remit by the ICAO to run the London VAAC and provide expected Ash distribution for the next 24hours. It is not responsible for sending monitoring gubbins into the sky.

The reporting to the CAA and NATS can then use other information as they see fit - test flights, balloon instrument monitoring etc.

LIEdar not Lidar

They should rename it if its basically a bit bollox.

Mines the one covered in volcanic ash

We like El Reg

as long as they stay within competence boundaries. Weather forecasting or air traffic control apparently are outwith. Zero article zone, El Reg!

@Robert Carnegie

http://www.flightglobal.com/articles/2010/04/19/340763/case-study-when-volcanic-ash-brought-down-a-747.html

Worst case, all engines fail - oh, and you can't see where you're going, which MIGHT under the Top Gear over/understeer principle be considered a blessing... http://www.youtube.com/watch?v=EQWPumtDXk0

We love El Reg

as long as they talk about stuff they know. Thus not weather forecast and air traffic control.

Vulture 1 + Balloons? How exactly?

"Field testing from balloons ... would have filled the knowledge gap."

So, we need to cover an area of about 4,000 miles square at, say, 200 mile intervals or better, sampling every few thousand feet up at six-hourly intervals. Even if there were some means to perform remote assessment, so that it wasn't necessary to collect the samples after descent and examine them under a microscope or whatever, at least half of the 400 field stations would have to be sea-based.

Rather than the rant against the Met it might be nice to know a bit more about how LIDAR works and to have a few details of the software they and the other eight VAACs worldwide use to model pollution incidents and the sort of kit they run it on.

Model not updated *since* 1986?

Don't know if that is or is not correct. Pretty suspect if it is. The physics, mathematical techniques and AFAIK the number of sensors have *all* improved.

Note 3 other facts.

Procedures *do* exist to handle the simultaneous shutdown of all engines.

Other parts of European airspace *have* re-opened, some of them undoubtedly flying through the UK sectors. If *nothing* happens on those flights the Met Office will look like it's crying wolf.

A number of long duration "weather reconnaissance" drones exist which could run sampling missions. These vehicles are usually propeller driven and while not very fast could sample most of the airspace fairly quickly. Being uncrewed if anything did happen they would be expendable.

Aviation sensors 101

A Engineer here again.

Some readers may be aware that aircraft use things called "Pitot tubes" to measure airspeed. Fwiw, airspeed is *not* the same speed as you'd get from asking a GPS how fast you're moving, because airspeed factors in the influence of the wind as well. This is an important difference if you want the aircraft to stay in the air.

In June 2009 Air France flight 447 crashed into the Atlantic killing all 228 people on board. It is suspected that simultaneous identical faults on two of three Pitot tubes, leading to misleading numbers being reported, caused the aircraft's control systems to "do the right thing" based on the information received, with disastrous results.

It is entirely plausible (indeed, predictable) that Pitot tubes will be adversely affected by atmospheric ash, either immediately or as time goes by.

There are probably other aircraft systems and sensors that can be affected by ash too. Engine and airspeed sensors just happen to be quite important to safety. BA and BAA revenue isn't really quite so safety critical.

Mean ash cloud

The ash cloud from Eyjafjallajökull was quite mean and big few days ago. The eruption now is about four times bigger then last eruption in 2004 in Grímsfjalli.

Ash also makes a jet engine into a scrap engine in no time. Things will get better when Eyjafjallajökull has stopped erupted. But until then, hope for the best.

ex-Rolls Royce research director speaks

A Engineer again again.

But this time you don't have to listen to me. Instead, listen to Professor Alan Turner of Sussex University, former head of a relevant Rolls Royce research organisation, someone who might just know something about the subject.

"Alan Turner is a Professor Emeritus in the School of Engineering and Design at the University of Sussex, UK, and Founding Director of the Rolls Royce Aero-Thermal Systems Research Centre. For over 25 years, his main activity was aero-thermal systems research on large turbofans (Trent) and military engines at Rolls Royce plc"

Large turbofans (such as Trent) are what power all modern long range civil aircraft.

Interviewed on BBC R5 Live, starting at about 2h 7m in.

http://www.bbc.co.uk/iplayer/episode/b00s1tqg/5_live_Drive_19_04_2010/

Turner or Walsh. Take your pick.

Why do you all hate science?

You volcanic ash cloud deniers are all the same. Trying to tell me that the sky is blue, when my model clearly says that it is lollipops. Next you'll be telling me that bumblebees can fly.

Why are there so many idiots around?

There is patently not a problem.

Yet people are queuing up to make 'authoritative' claims that there is. It's beginning to sound exactly like Global Warming....

What is it about various sections of humanity that makes them want to pretend the end of the world is coming? And why do the press keep reporting this? ?????

Listened to Dr Turner

Side note. Single crystal turbine blades are *very* expensive and AFAIK remain confined to military gas turbines. Unlike Silicon they are not grown from a seed crystal. Gas turbine blade clearance is on the order of a 4-8 mils (c100-200 micrometres, which is tight but I think the ash is *smaller* than this)

Dr Turner makes a more general point. All modern aircraft turbine blades are *cooled*. They use "300micrometre holes in about 6 rows" The sand melts and blocks the holes. This mechanism is what allows blades to operate at (IIRC) 80-90% of their melting point. Disrupting this airflow is therefor a Very Bad Thing.

Dr Turner criticized airline test flights as failing to test for loss of power after landing and borescoping the engine for damage. Damage would also show up as worse fuel consumption which should be apparent given the high resoltuion of engine management data recording. Given the revenue losses they are having airlines ideas of "Acceptable risk" might well be a lot different to what the general public's is.

Dr Turner makes a lot of sense but I think he may underestimate the ability of an engine to recover if shut down at altitude and allowed to glide to lower (12000 ft) levels to crack the glass off. He did point out that airlines in the Middle East do fly into dust storms at 30 000 ft so in this area its effects on engine life are quantifiable. At the end of the day an airline has to be in business to be worrying the overhaul costs on its engines. For some not flying *now* might be the last straw.

Rolls Royce CEO on "single crystal"

Here are some words from Rolls Royce on the subject of single crystal turbine blades. These particular words are from Sir John Rose, Rolls Royce plc Chief Executive, in a 2009 speech to the Royal Society of Arts on "creating a high value economy". Not totally definitive, and doesn't illustrate the history of single crystal going back several years, but will it do for now? It's the best I could quickly find.

<begin quote>

Let me illustrate the point by taking just one small component. This is a ‘single crystal turbine blade’.

• It’s one of 66 in a Trent 1000 engine.

• It is grown in a vacuum furnace from a single crystal of a proprietary Rolls-Royce alloy.

• It operates in the high-pressure turbine, where gas temperatures are up to 1,600 degrees centigrade – that’s around 200 degrees centigrade higher than the melting point of the alloy from which it is made.

• It delivers the same horse power as a Formula One racing car.

• Because of the extraordinary precision required to ensure maximum efficiency and safety, the blade’s dimensions cannot be ‘out’ by more than 10 microns – that’s 10 times less than the width of a human hair.

• Yet, for all its complexity, it travels seven million miles between major services.

• A component of this complexity demands the close involvement of an enormous number of parties outside Rolls-Royce: in this case 37 universities and research centres around the world, 35 large companies and 34 small or medium sized companies.

• Unsurprisingly, it is not cheap. In fact, this small component costs around $10,000, the equivalent of over $1,000 an ounce.

<end quote>

Rose goes on to mention the Electronic Engine Control (aka FADEC), whose programming allows the engine to operate close to the limits of **normal operating parameters**. What he does't say is that ash ingestion is not within those "normal operating parameters" and the EEC's programming almost certainly is not intended to cater for those circumstances.

The traditionally engineered safety margins which might have been expected in the days of analogue controls have been sacrificed in recent years and in many industries in the interests of better economy. Consequently there is now less "wiggle room" for safety when exceptional circumstances do occasionally arise.

Full text (worth a look) at http://www.thersa.org/__data/assets/pdf_file/0007/249154/Rose-RSA-speech-10-November-2009.pdf

Single crystal blades, operating at temperatures ABOVE their melting point

The single crystal turbine blades are operating in gases whose temperature is above the blade's melting point, hence the critical importance of the cooling vents mentioned above by various folk.

Don't take my word for it, read the words of John Rose, CEO of Rolls Royce plc, addressing the Royal Society of Arts on "creating a high value economy" (it's worth a read anyway).

For the "single crystal blade" stuff start at page 4 of

http://www.thersa.org/__data/assets/pdf_file/0007/249154/Rose-RSA-speech-10-November-2009.pdf

Per ardua ad astra

Telescopes, starlight and science might provide all that's needed for informed decision making here.