Non-motoring > Ash Doubts Miscellaneous
Thread Author: Runfer D'Hills Replies: 44

 Ash Doubts - Runfer D'Hills
news.aol.co.uk/branson-new-restrictions-a-joke/article/20100516074531152231189

This getting silly isn't it ? OK they had to establish if it was a real problem. Clearly it isn't. Costing millions now needlessly.

I should be flying again this week and if they let me I will.
 Ash Doubts - Manatee
"Sir Richard said there was no evidence planes could not fly safely. "

Well that's all right then.

I recall there being no evidence that BSE was transmissible to humans.

The professionals can't agree on it.

goo.gl/v63o
 Ash Doubts - Iffy
...if they let me I will...

I remember when London's railway termini were routinely closed at going home times due to bomb scares in the 1980s.

The general view of the delayed commuters - me included - was 'run the gauntlet'.

There was probably little risk then on the railways as there is now in the air.

But let's not decide on the say-so of people with vested interests such as Branson.

 Ash Doubts - Zero
problem is, that planes fall on others.

If it were up to me, I would say fly and be damned. Some poor sod underneath might regret that tho.
 Ash Doubts - spamcan61
I'm supposed to be going back to work in sunny Stockholm on the 07:35 out of Heathrow tomorrow morning, not sure if it's worth the bother of packing my suitcase at the moment. :-/

Don't fancy doing the 48 hr. overland route again.........
 Ash Doubts - Zero
you dont have much luck with timing do you
 Ash Doubts - spamcan61
>> you dont have much luck with timing do you
>>

No I don't ! Then of course there's the BA strikes to contend with. Sometimes a nice simple commute up and down the M3/M27/A31 in my lovely Vectra like I used to do seems like heaven...
 Ash Doubts - Stuartli
I blame the new coalition and, in particular, Paddy Ashdown.
 Ash Doubts - MD
Paddy Ashup surely?
 Ash Doubts - rtj70
I have somehow managed to fit in a two week holiday to a Greek island between the ash cloud problems. Lucky me.

When it looked like restrictions would be lifted before we went, I emailed someone who worked for a jet engine company... when planes were not flying he seemed to think it was appropriate and would not fly. There is sure to be damage to engines on planes.... who knows what happened to that plane into Libya.
 Ash Doubts - henry k
>>who knows what happened to that plane into Libya.
>>
Latest thinking on the pilots forum is that it landed short and off line to the runway. That knocked the tail off as they attempted to go round again.
 Ash Doubts - R.P.
Friends in the "industry" mention a lack of ILS at Tripoli.......RJ, is there any substance to the Ash theory ?
 Ash Doubts - rtj70
It was mentioned on BBC World News when I was in Greece. Didn't watch much TV when in Greece mind. This was soon after the crash so little information was available I guess.

Lack of ILS doesn't sound that smart either.
 Ash Doubts - R.P.
Ah the same World Service who had this Volcano in Ireland when we were listening in the States - we laughed out rather loudly at that.
 Ash Doubts - -
OK, say i own a plane and my customers are prepared to run the risk....if i agreed to fly them on the condition that should ash cause several hundred thousand pounds worth of paint/engine damage then the customers jointly pay for the damage.
Would they be so keen then.
 Ash Doubts - Bromptonaut
No connection with the Tripoli crash but I'd have thought latent damage, rather than planes falling from the sky is the real risk in low density ash.

Best case might be fuel consumption or power deficiencies on multiple engines in fleet and a log jam in the workshops. Worst case is a call for max power (do engines still have 'auto performance reserve' or overboost?) on go around being followed by engine failure(s).
 Ash Doubts - Runfer D'Hills
Re Northern Irish Volcanoes.......Reminds me of the Belfast shoplifter who has just been released after serving 20 years in jail. His sentence seemed a bit extreme until it was revealed that he lifted Marks and Spencers......

er....boom boom ?
 Ash Doubts - Zero
>> Lack of ILS doesn't sound that smart either.

Very much more common than you would like to think. There are loads of commercial airports that are visual.
 Ash Doubts - spamcan61
Ah well, after an ominous 03:30 start this morning when it looked like LHR was going to be shut due to ash related challenges we finally took off around 07:55 and got into Stockholm on time. Now wandering around my 17th century stone walled apartment B&B in the old town trying to get a decent wifi signal.
 Ash Doubts - smokie
"Now wandering around my 17th century stone walled apartment B&B in the old town trying to get a decent wifi signal."

Did you find one?



I guess you did...
 Ash Doubts - CGNorwich
A modern weather rhyme:

Ash before Oak,
We shall have soak.

Ash in the sky,
No one shall fly

(Today's Times)
 Ash Doubts - R.P.
I actually have a photo of the ash cloud over Ireland from the Welsh coast - I'll ask the chap who took it if I can post it.
 Ash Doubts - Perky Penguin
SFAIK this ash can, when subjected to the sort of temperatures found in jet engines, form a sort of glassy coating on the blades. This upsets the aerodynamics of the blades and could cause the engine to lose efficiency or to "stall". Further to this the blades are subjected to horrendous temperatures and have to be cooled by means of small airways within their structure. If these are blocked the blades may overheat and this can result is sudden and catastrophic failure of the engine.Not a risk I need to take, personally, thanks!
 Ash Doubts - John H

>> can result is sudden and catastrophic failure of the engine.Not a risk I need to
>> take, personally, thanks!
>>

The new concentration of ash deemed safe to fly in is equivalent to two grains of sand in a bath tub. Decisions taken by ultra elfandsafety conscious people who fear more for thier state jobs than in the private industry they are destroying.
 Ash Doubts - Bromptonaut
>> The new concentration of ash deemed safe to fly in is equivalent to two grains
>> of sand in a bath tub. Decisions taken by ultra elfandsafety conscious people who fear
>> more for thier state jobs than in the private industry they are destroying.

Press reports suggest that the potential difficulty with ash in areas of high air traffic density (ie where 'avoid' is not viable) has been forseen for years. The private sector manufacturers and private sector airlines were not prepared to take the risk of theoretical work on safe limits.

But of course that model does not fit the 'safe state jobs' zeitgiest.
Last edited by: Bromptonaut on Tue 18 May 10 at 14:13
 Ash Doubts - John H

>> The private sector
>> manufacturers and private sector airlines were not prepared to take the risk of theoretical work
>> on safe limits.
>>
>> But of course that model does not fit the 'safe state jobs' zeitgiest.
>>

Utter nonsense.
The US system leaves air carriers with the responsibility to determine whether or not it is safe to fly. Under European rules, member states have the power to decide whether or not their airspace should be open. Decisions taken by these bureacrats have been guided by computer models from the Volcanic Ash Centre in London and Eurocontrol. These computer models have proved to be wildly inaccurate. A CAA spokesman said: ‘The Met Office model was predicting ash which was not there when the test flights were done. We have asked the Met Office why their forecast model showed something which was not subsequently backed up.’ The Met Office said that observation, laser checks of the dust in the atmosphere and supplementary evidence from test flights showed that the ash was present over the South East but not in the levels that require grounding of aircraft.
 Ash Doubts - rtj70
If a volcano erupted in say Hawaii and ash got into the atmosphere... how would airlines, NATs, CAA etc know it affected the UK airspace or not? The ash cloud from Iceland's progress is being tracked using weather simulation models. In this instance they can probably check it using planes. But volcanic ash from a long way away?

Okay my example of Hawaii is perhaps not applicable but what if something nearer a jet stream erupted?

I stand by what a friend said about flying a jet plane through ash cloud. He only worked for a jet engine company in special projects mind.
 Ash Doubts - mikeyb
I work for a manufacturer of "large" aircraft. We sent two test aircraft up and flew them around in the ash for 5 hours during the first flight ban. Result was that no impact on aircraft / engine was found......

Crash in Tripoli is very likely to be attributed to Pilot Error
 Ash Doubts - R.P.
Pilot Error


That was the chatter amongst my friends in the trade as well, no mention of the ash, hence my question to RJ.
 Ash Doubts - rtj70
>> hence my question to RJ.

I only quoted what I'd heard in my absence. I find we are lucky to have got to Greece and back between Ash Cloud problems!

Until engines are fully checked, then do not assume no problems. The friend/contact I quoted before about flying in a jet aircraft through ash cloud may be retired but had a senior job. He retired a long time ago... but they were working on the VTOL engine for the new F35 back then.
 Ash Doubts - Fursty Ferret
Rules keep changing. Airline I fly for has found very low levels of ash in filters but no engine contamination (A320). Have been checking the fan blades after every flight, never found any ash on them.

The concern now isn't so much about spectacular engine failure but an inability to monitor possible gradual damage from ash leading to early failure down the line. Though since the MTBF of a modern engine is circa 40 years, I'm not desperately concerned.
 Ash Doubts - Zero
Yeah, but you dont exactly run an aero power plant for 40 years and then chuck it away do you.
 Ash Doubts - Bromptonaut
I'd come to the same conclusion as an amateur so it's quite touching to see the proffessionals agree!!
 Ash Doubts - Netsur
Bit cheesed off with Jet2. Our flight on Monday morning was half boarded when they took us off for two hours "as the airport has closed due to ash" . However at the same time, six other flights took off. Never got to the bottom of it.
 Ash Doubts - Number_Cruncher
>>Until engines are fully checked, then do not assume no problems.

This would be exactly my view of the situation as well.

The conditions under which this type of ash from this particular volcano begin to adhere to hot engine parts and form a deposit and / or block cooling passages cannot be known at the moment. Results obtained from one engine type with it's own particular turbine inlet temperature and turbine and nozzle guide vane materials and cooling solution won't necessarily transfer to other types.

As the failure is due to an accumulation of material, then surely the density AND duration need to be summed up and compared against an engine's inspection interval to determine whether or not a safe margin exists - is there any work going on to enable this type of summation to be performed?

I had some involvement with the F35 work - working on compressor rotors for the F136 engine and one of the rotors of the lift fan. Some colleagues were working on the swivel nozzle at the back of the plane, and that is a truly weird design!
 Ash Doubts - R.P.
and that is a truly weird design!

Almost alien really.
 Ash Doubts - rtj70
Number_Cruncher, looks like you probably know the person I quoted earlier about flying in a jet aircraft through ash clouds.
 Ash Doubts - Number_Cruncher
Possibly - on those projects, I was working at the manufacturing end rather than the design or development phase - there was some very interesting work getting a newand innovative process to work properly.

The machine to make the parts produced truly massive loads, and although stories usually talk about the exotic materials required in the engines, we needed to use some very expensive and difficult to machine materials to make the tooling.

One odd problem was that the loads were so high that massive parts which were machined to be, say, cylindrical deformed into a barrel shape and jammed when under load. I ended up calculating the deformed shapes, and then getting the parts re-machined with the negative of the deformation so that they became "true" when under load in the machine. It was quite frightening for me when we first ran the machine with our parts in it, and I was very happy to find everything in one piece after the run!

 Ash Doubts - bathtub tom
>>two grains of sand in a bath tub

But it depends where those grains are. I'm sure we've all found sand to be most uncomfortable in certain places. ;>)
 Ash Doubts - Dog
On 24 June 1982, Flight 9, a Boeing 747-200, G-BDXH, City of Edinburgh flew through a cloud of volcanic ash and dust from the eruption of Mount Galunggung, causing extensive damage to the aircraft, including the failure of all four engines.[150] The crew managed to glide the plane out of the dust cloud and restart all four of its engines, although one later had to be shut down again. The aircraft made an emergency landing at Halim Perdanakusuma International Airport just outside Jakarta. No-one was injured

...!
 Ash Doubts - R.P.
That's the incident that got them all worried this time around. There was a good programme about it on one of the sat channels, "Seconds from Disaster" or somesuch. They were wheeling the good Captain out for interviews whilst we were in the States.
 Ash Doubts - Dog
I stumbled upon that dust incident whilst reading up on B.A.
www.bing.com/reference/semhtml?title=British_Airways&src=mtoc&fwd=1&qpvt=british+airways&q=british+airways
Its under incidents and accidents.
 Ash Doubts - Zero
he flew through the plume of dust. A lot of it and very close. Enough to choke the engines and block the pito heads.

To do the same with our local volcano you would have to head for it and fly straight through the plume.
 Ash Doubts - Auntie Lockbrakes
The entire fuss is just a load of hot air I reckon :-)
 Ash Doubts - Zero
your only jealous cos your local volcano is on strike.
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