flightradar24...not down just heavily oversubscribed!

At 1329 local (UK) showing just 1 aircraft in flight over the entire UK, a Citation operated by 247Jet at 1700 feet and 205kts Biggin Hill to Southend

Still a few flights over Sweden and Finland but Norway and Denmark deserted like the UK.

pp

No...no...no Iceland, we said give us your cash!

Ressie, my guess would be nil chance.

http://metoffice.gov.uk/aviation/vaa...1271331761.png

6:00am projected ash cloud is bottom right...

Can a techie please explain to me the technical implications of flying through a volcanic dust cloud? (i'm referring to turbofan engines).

Is it because the oxygen content of the air is so low that there cannot be combustion of the fuel and the engines may flame out? (per the BA flight in '82?).

Could there also be an engine wear issue - abrasive dust getting in to bearings/abrading fan blades etc?

Would it also affect pitot readings?

Apologies if this seems a stupid question to those in the know, but i'm SLF not an aeronautical technician :ok:

TIA :)

"http://metoffice.gov.uk/aviation/vaa...1271331761.png

6:00am projected ash cloud is bottom right..."

Large parts of Germany and Poland are going to be affected. Obama is supposed to be In Krakow for the funeral on Sunday - that may not happen.

This is going to cost a hell of a lot of money. Hello double dip recession.

Engine effects
 

Good quick summary on the beeb on engine, etc, effects
BBC News - Iceland volcano: Why a cloud of ash has grounded flights
From ex-Pres of RAeS so accurate

DAve TS, it is because the ash will accumulate on every thing and at the same time be very abrasive (think of sand blasting and you will get the idea).

The ash will accumulate in the flame cans (where the flame is held) inside the engines and eventually turn from ash into glass and stick to everything inside the engine.
Thus starving the flame cans of air and extinguishing the engines.

Once the flame goes out the glass will cool solidifying even more but becoming brittle as well.

If the pilot is lucky they may be able to shed the glass and restart the engines.

This is what (I believe) happened back in 1982 near Indonesia.

If I am wrong then please correct me.

Litigation, Litigation, and Litigation
 

JonC,

Happy gliding! (Assume it'll be a winch-launch?)

The latest chart fom the UK Met Office's VAAC (Volcanic Ash Advisory Centre) is here (as already mentioned on robdean's post):
http://www.metoffice.gov.uk/aviation/vaac/data/VAG_1271331761.png

These are forecast charts, covering the surface to FL550 in three layers.

To quote a footnote from the chart:
"Rmk: Ash concentrations within the indicated areas are unknown."

The following is a quote from the Met Office website:

"The Met Office is continuing to monitor the spread of the ash plume from eruption of the Eyjafjallajökull volcano on Iceland.
Our forecasters monitor volcanic eruptions as part of the Met Office’s role in the global network of Volcanic Ash Advisory Centres (VAAC). Our Environment Monitoring and Response Centre (EMARC) is working closely with the Icelandic Met Service to study the plume and predict where it may spread as the situation develops.
Volcanic ash can be dangerous for aircraft, causing damage, reducing visibility, and potentially clogging engines. Through EMARC we’re responsible for the Iceland area.
Using observations from Iceland, satellite imagery and our specialist model which predicts how pollutants move through the atmosphere, we’ve sent out advisories to keep the aviation industry and pilots aware of the situation."

Am beginning to wish we had a Meteorology forum on PPRuNe.

Having interpreted these advisories, has NATS itself taken the decision to close UK CAS (with advice from its own lawyers), or has it been leaned-on by HM Government?

Chris

ash
 

dutch airspace closed from 17z on.

cash, not ash!
 

Flightradar, 1300 utc:

http://img217.imageshack.us/img217/3...htradar.th.jpg

:ooh:

Dave T-S
 

More or less all of those things Dave. The engines from BA009 were completely totalled, due to accreated pumice on all the hot surfaces. Plus the pumice would have ground the bearings square and changed the profile of all the gas passages. The fact that Capt. Moody and his crew got them restarted is really the clearest demonstration of just how amazing modern high bypass fan jets are. Their enormous power, coupled with fuel frugality at altitude and metronomic reliabilty, make them truly awesome machines.

Oh, and the cockpit windscreens were abraided opaque as were the landing light lenses and vitually all the paint on leading surfaces.

Roger.

"has NATS itself taken the decision to close UK CAS (with advice from its own lawyers), or has it been leaned-on by HM Government?"

Decisions like this were take years ago. When the event occurs the plan is implemented. You do not wait until an a volcano erupts an the plume start blowing towards you to debate the relative merits of open/closing the CAS.

Planning for a nuclear war/tsunami/asteroid strike/pandemic flu or whatever you have a contingency plan and you implement it. The words of the press release, the speech of the PM or whatever - it was all written long ago.

Jackieofalltrades, right click on the photo and "Properties" gives you http://oiswww.eumetsat.org/IPPS/html.../HxoQZlgSBaEbp

You can find them here: EUMETSAT IPPS animation - Latest Images

Meteosat 0 degree, dust, Western Europe show it up the most

Dave, Now you know as much as I do :)

Danger to Aircraft from Volcanic Eruption Clouds and Volcanic Ash

Ash Reduces Engine Performance and May Cause Engine Failure
Ash ingested by jet engines may lead to the immediate deterioration in engine performance and engine failure. The principal cause of engine failure is the deposition of ash in the hot sections of the engine. Glass from melting volcanic ash will coat fuel nozzles, the combustor, and turbine, which reduces the efficiency of fuel mixing and restricts air passing through the engine. This causes surging, flame out, and immediate loss of engine thrust.

Ash Abrades External Components of Airplanes

Volcanic ash is highly abrasive because it consists of hard, sharp rock fragments that easily scratch and erode plastic, glass, and metals. Any forward-facing surface of an airplane is likely to be damaged . . . Cockpit windows may become so abraded and scratched that pilots have extreme difficulty seeing the runway on which to land the plane.

Aero 09 - Volcanic Ash Avoidance

Reduce thrust to idle immediately. By reducing thrust, engines may suffer less buildup of molten debris on turbine blades and hot-section components.
Exit the ash cloud as quickly as possible. (NSS! ed.) A 180-deg turn out of the ash cloud using a descending turn is the quickest exit strategy.

Have UK Military aircraft been grounded also? Its eeriliy quiet here in the Vale of York.

Many thanks, but is there a "live" version with regular updates?

Fake Sealion
 

I guess one jet engine is the same as another regardless of whether its military or commercial.

They're required to confirm with MO whether to fly or not; I think that we can all guess MO's answer.

G

According to BBC, NATS now say flights will not resume until 0600 tomorrow (16th April) at the earliest.