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This person s favorite of mine and does an excellent job explaining aircraft incidents. To answer your question here is british airways flight 9
Here is him doing a more in depth for the specific hazards of volcanic ash
Volcanic ash is not the same as wood ash. Volcanic eruptions spit out a ton of microscopic rocks and glass particles that are the same hardness as steel. If those particles got into an engine, it would act like sand paper and grind down the precision surfaces.
Volcanic ash includes silica, wood ash includes carbon.
The temperatures inside an engine after the combustion chamber are extremely high, so much so, that the used materials loose strength and could not withstand the centrifugal forces of the rotation. This is why the turbine blades are actively cooled.
Modern engines take “relatively” cool air (600°C) from the high pressure compressor just before the combustor and send it through thousands of tiny laser-drilled holes to apply a cooling and insulating film on the turbine blades.
If there is wooden ash particulate inside the air, it will have burnt off at those temperatures long before being ingested by the cooling system.
If there is silica particulate in the air, it will melt and plug up those tiny cooling holes. If your turbine blade cooling fails, your engine will very soon not have turbine blades any more and subsequently stop being an engine.
Volcanic ash includes silica, wood ash includes carbon.
The temperatures inside an engine after the combustion chamber are extremely high, so much so, that the used materials loose strength and could not withstand the centrifugal forces of the rotation. This is why the turbine blades are actively cooled.
Modern engines take “relatively” cool air (600°C) from the high pressure compressor just before the combustor and send it through thousands of tiny laser-drilled holes to apply a cooling and insulating film on the turbine blades.
If there is wooden ash particulate inside the air, it will have burnt off at those temperatures long before being ingested by the cooling system.
If there is silica particulate in the air, it will melt and plug up those tiny cooling holes. If your turbine blade cooling fails, your engine will very soon not have turbine blades any more and subsequently stop being an engine.
It’s a lot denser and it can clog things.
The engine uses air for many things, some compressor bleed air will be used to operate mechanisms of the engine.
For example some thrust reverser deployment.
Some sensors of the engine computer. The air conditioning and pressurization of the plane.
For this reason alone you are at risk of faulty thrust reversers, faulty engine control, faulty pressurization.
Then there’s the direct clogging of engine power production, such as clogging of fuel nozzles air passages that swirls the fuel in the chamber, leading to combustion chamber failures due to poor fuel spray pattern, with partial or total loss of power.
Blockage or jamming of bleed air valves may force the engine to surge or stall at reduced power settings, leading to complete engine loss at landing, preventing to reject a landing. Just with this you are risking to be forced to an emergency landing with no second try.
This considering just severe ingestion of light particles. And the above are all no-go items in the sense that such faults need repair or deactivations to be flown. You can’t legally fly into that situation, it’s not allowed by rules. You are allowed to fly into things that are normal, never allowed to fly people taking chances.
Then if engine ingests rocks… compressor blades rotate at 1000kmh, ingesting stuff at 1000kmh, that’s gun bullet speed. You are literally machine gunning the blades. It’s not a good idea.
For comparison, forest fires don’t have a smoke plume that reach the altitudes of planes, and doesn’t contain rock particles but wood ash particles, that are incredibly light. And still you don’t fly into forest fire smoke with passengers on board. Dedicated firefighting planes can, but that’s a specific job with specific training.
Volcanic ash can reach above the troposphere and has silicon in it and can get in an aircraft engine and choke out the oxygen and also wreak havoc on the windows and airframe of the aircraft.
Forest fires are never reach high enough with enough density to cause problems for aircraft and in some places of the world like Indonesia they fly in to heavy areas of smoke without any short term problems.
Aircraft maintenance takes care of long term carbon build up as aircraft engines have to be maintained and replaced on a maintenance based schedule
It’s a lot denser and it can clog things.
The engine uses air for many things, some compressor bleed air will be used to operate mechanisms of the engine.
For example some thrust reverser deployment.
Some sensors of the engine computer. The air conditioning and pressurization of the plane.
For this reason alone you are at risk of faulty thrust reversers, faulty engine control, faulty pressurization.
Then there’s the direct clogging of engine power production, such as clogging of fuel nozzles air passages that swirls the fuel in the chamber, leading to combustion chamber failures due to poor fuel spray pattern, with partial or total loss of power.
Blockage or jamming of bleed air valves may force the engine to surge or stall at reduced power settings, leading to complete engine loss at landing, preventing to reject a landing. Just with this you are risking to be forced to an emergency landing with no second try.
This considering just severe ingestion of light particles. And the above are all no-go items in the sense that such faults need repair or deactivations to be flown. You can’t legally fly into that situation, it’s not allowed by rules. You are allowed to fly into things that are normal, never allowed to fly people taking chances.
Then if engine ingests rocks… compressor blades rotate at 1000kmh, ingesting stuff at 1000kmh, that’s gun bullet speed. You are literally machine gunning the blades. It’s not a good idea.
For comparison, forest fires don’t have a smoke plume that reach the altitudes of planes, and doesn’t contain rock particles but wood ash particles, that are incredibly light. And still you don’t fly into forest fire smoke with passengers on board. Dedicated firefighting planes can, but that’s a specific job with specific training.
Volcanic ash can reach above the troposphere and has silicon in it and can get in an aircraft engine and choke out the oxygen and also wreak havoc on the windows and airframe of the aircraft.
Forest fires are never reach high enough with enough density to cause problems for aircraft and in some places of the world like Indonesia they fly in to heavy areas of smoke without any short term problems.
Aircraft maintenance takes care of long term carbon build up as aircraft engines have to be maintained and replaced on a maintenance based schedule
Volcanic ash is rock. Turns in to pumas often times. Ever see Pompeii? Those people? Yea they were covered with volcanic ash. If I plane flies through volcanic ash can look like that and cause big issues
Volcanic ash is rock. Turns in to pumas often times. Ever see Pompeii? Those people? Yea they were covered with volcanic ash. If I plane flies through volcanic ash can look like that and cause big issues
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