Volcanic Ash
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Join Date: Mar 2004
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Volcanic Ash
Hello,
for porbably the first time in my aviation career I feel very uneasy about making go/no-go decisions, regarding the VA.
Background: I fly a little cooperate jet (Citation Sovereign) and we are just 2 pilots, no overhead.
I supplied my superiors with the info I could gather in April, one of which was the maintenance manual stating that the engines would need a HSI after VA encounter. There is NO method of how detect VA encounter mentioned, neither in the engine MM, nor the AFM/OM (clearly, abrasions etc would be a sign). Now as the maps provided are IMO sadly inadequate and the engine/airframe manufactureres have diverted from their zero ash to 2mG ash concentration, Iīd like to know how to decide. I donīt want the blame if during boroscopic inspection VA is discovered with the ensueing cost and downtime. (which is considerable with a contracted mx and no spare engines owned)
A real catch 22 methinks. What are your views? Do the airlines just gamble on their engines life?
Thanks for the input.
for porbably the first time in my aviation career I feel very uneasy about making go/no-go decisions, regarding the VA.
Background: I fly a little cooperate jet (Citation Sovereign) and we are just 2 pilots, no overhead.
I supplied my superiors with the info I could gather in April, one of which was the maintenance manual stating that the engines would need a HSI after VA encounter. There is NO method of how detect VA encounter mentioned, neither in the engine MM, nor the AFM/OM (clearly, abrasions etc would be a sign). Now as the maps provided are IMO sadly inadequate and the engine/airframe manufactureres have diverted from their zero ash to 2mG ash concentration, Iīd like to know how to decide. I donīt want the blame if during boroscopic inspection VA is discovered with the ensueing cost and downtime. (which is considerable with a contracted mx and no spare engines owned)
A real catch 22 methinks. What are your views? Do the airlines just gamble on their engines life?
Thanks for the input.
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Ash is detected by flight crews using the following:
A smell of sulphur, or burning.
A red glow in the engine intakes.
High EGT/TIT.
Vibration.
Abnormal pitot/static instrument readings.
The immediate response is to close the throttles and turn 180 degrees to leave the area. When clear, add enough power to remain airborne until sure you are clear of all ash.
The ash will pass through the engine with minimal damage if the engine is at idle because the temperatures are not high enough to melt it. Continuing to run at settings higher than idle will maintain the temperatures.
You will also have ash damage to leading edges, pitot tubes, windscreens and the like, depending on the amount of ash and its contents.
Not all ash clouds will be forecast. Any cloud might contain ash, especially when flying the Ring of Fire (and near Iceland!).
A smell of sulphur, or burning.
A red glow in the engine intakes.
High EGT/TIT.
Vibration.
Abnormal pitot/static instrument readings.
The immediate response is to close the throttles and turn 180 degrees to leave the area. When clear, add enough power to remain airborne until sure you are clear of all ash.
The ash will pass through the engine with minimal damage if the engine is at idle because the temperatures are not high enough to melt it. Continuing to run at settings higher than idle will maintain the temperatures.
You will also have ash damage to leading edges, pitot tubes, windscreens and the like, depending on the amount of ash and its contents.
Not all ash clouds will be forecast. Any cloud might contain ash, especially when flying the Ring of Fire (and near Iceland!).
Join Date: Jun 2009
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well...
his dudeness wrote:
where did you get that info from???
They DID NOT. Some UK CAA official brabbled something to that extent, but it is not true..
For ALL engine manufacturers it is still "zero ash tolerance" and it will stay that way..
Yes, they do, and on the lives of their passengers... ( those airlines I mean who constantly are trying to bull....everybody into thinking that flying into volcanic ash were safe...)
There is no catch 22...
If you fly into an area as defined by "aviation color red" as the London VAAC hand out, you are flying into a SIGMET'ed danger zone..
if nothing happens, so be it..
IF, HOWEVER something happens, it is YOUR rear-end as PIC on the line..
And by the way, ALL engine manufacturers treat an ash encounter, no matter what concentration, as an FOD matter and regard it as "operational abuse", means no warranties, no liabilities...
nothing, zinch, zero..
so, if nothing else holds you back from flying in a VAAC designated area, you could tell your aircraft owner, that if something happens, not big stuff, just a bit, HE will have to pay for all maintenance and restoration the engines may need afterwards...( no engine service plan and no warranty contract will apply to ANY ash damage..) and on a Cessna Sovereign that could be a cool 2 Mio USD per side, if not more...
maybe he then, with that information in hand,your aircraft owner WILL ask YOU to delay any flight until the VAAC cloud has passed either from your departure point, or anywhere enroute, or from your destination
it's as simple as that at the end of the day...
Now as the maps provided are IMO sadly inadequate and the engine/airframe manufactureres have diverted from their zero ash to 2mG ash concentration,
They DID NOT. Some UK CAA official brabbled something to that extent, but it is not true..
For ALL engine manufacturers it is still "zero ash tolerance" and it will stay that way..
Do the airlines just gamble on their engines life?
There is no catch 22...
If you fly into an area as defined by "aviation color red" as the London VAAC hand out, you are flying into a SIGMET'ed danger zone..
if nothing happens, so be it..
IF, HOWEVER something happens, it is YOUR rear-end as PIC on the line..
And by the way, ALL engine manufacturers treat an ash encounter, no matter what concentration, as an FOD matter and regard it as "operational abuse", means no warranties, no liabilities...
nothing, zinch, zero..
so, if nothing else holds you back from flying in a VAAC designated area, you could tell your aircraft owner, that if something happens, not big stuff, just a bit, HE will have to pay for all maintenance and restoration the engines may need afterwards...( no engine service plan and no warranty contract will apply to ANY ash damage..) and on a Cessna Sovereign that could be a cool 2 Mio USD per side, if not more...
maybe he then, with that information in hand,your aircraft owner WILL ask YOU to delay any flight until the VAAC cloud has passed either from your departure point, or anywhere enroute, or from your destination
it's as simple as that at the end of the day...
Last edited by falconer1; 10th May 2010 at 17:21.
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volcanic ash
I fly a Kingair with PT6A engines.
PW have issued a guidance, SIL gen-102 - ENGINE OPERATING IN EUROPEAN AIRSPACE which as I understand it says you can fly in the red but not the black areas provided you undertake extra inspections which for my engine is a 50 hour check and a monthly check.
Maybe you should contact your engine manusfacturer to see if they have issued guidlines.
PW have issued a guidance, SIL gen-102 - ENGINE OPERATING IN EUROPEAN AIRSPACE which as I understand it says you can fly in the red but not the black areas provided you undertake extra inspections which for my engine is a 50 hour check and a monthly check.
Maybe you should contact your engine manusfacturer to see if they have issued guidlines.
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Flying into anything other than air has always been a user choice. The manufacturers simply provide you with guidance on recognizing and correcting any malfunctions that might occur.
The regulators provide you with statements of certified tolerance (birds, ice, hail etc.)
If these statements do not cover you then you are on your own.
Operating safely is a domain left to the operators who of course must not be found in violation of a regulation.
Guidance on assessing the level of safety for a specific flight may be developed in concert with all parties and as such would be approved under operational procedures.
The referenced documents from Boeing and Airbus above (IFALPA) are great starting points as is all the stuff about tracking red yellow and green (sic) areas of ash. But the final output from the consideration of this data rests with the operational experts and not with message boards.
IMO there is no way that anybody outside the loop of developing and reviewing thse operational procedures can make judgements on what is safe and what is not safe.
The regulators provide you with statements of certified tolerance (birds, ice, hail etc.)
If these statements do not cover you then you are on your own.
Operating safely is a domain left to the operators who of course must not be found in violation of a regulation.
Guidance on assessing the level of safety for a specific flight may be developed in concert with all parties and as such would be approved under operational procedures.
The referenced documents from Boeing and Airbus above (IFALPA) are great starting points as is all the stuff about tracking red yellow and green (sic) areas of ash. But the final output from the consideration of this data rests with the operational experts and not with message boards.
IMO there is no way that anybody outside the loop of developing and reviewing thse operational procedures can make judgements on what is safe and what is not safe.
