How does a volcanic eruption affect air travel and how are flight paths rerouted?
Volcanic ash harms aircraft mainly by damaging engines, and even thin ash can wear parts, so flights near or downwind of eruptions face real risk.
Covers: How volcanic ash damages aircraft and engines, how ash clouds are detected and forecast, and how airlines and air traffic control plan and execute reroutes and cancellations. Does not cover general aviation safety procedures or non-aviation climate effects in depth.
Also answers: How does a volcano's eruption affect air travel and how are flight paths rerouted? · Why do volcanoes cancel flights? · How do planes avoid volcanic ash clouds? · Volcanic ash air travel disruption explained
The short answer
Evidence-backed AI-prepared starting mapVolcanic ash threatens aircraft mainly through jet engines: ash melts in the hot turbine section and re-solidifies as glass on nozzles and blades, erodes compressor and turbine blades, and fouls fuel nozzles with carbon deposits. Together these can cause power loss, engine surge or flame-out; of the documented encounters reviewed, eight involved some loss… 12
In brief
Ash damages engines by glassifying on turbine parts, eroding blades and fouling fuel nozzles, which can cause power loss, surge or flame-out; no crashes have been attributed to ash.1
Evidence-backedAsh can be hazardous hundreds of miles from an eruption, and busy corridors run near many explosive volcanoes.2
Evidence-backedDispersion-model ensembles forecast ash location and column load reasonably well but underestimate 3D concentrations, so forecasts carry real uncertainty.3
Evidence-backedRerouting decisions balance using free airspace efficiently against short-notice postponement or cancellation, with air traffic control clearance as a gating factor.4
Evidence-backed
At a glance
The picture in numbers
Live · updated just now
300,000 passengers
The evidence behind it
6 sources- Other studies and data3
- Background3
When it was published
Newest from 2021
| Source | Kind | Year |
|---|---|---|
| Airborne volcanic ash; a global threat to aviation | Other studies and data | 2010 |
| Assessment and Characterization of Volcanic Ash Threat to Gas Turbine Engine Performance | Other studies and data | 2014 |
| Recent Encounters of Aircraft with Volcanic Ash Clouds | Background | 2015 |
| An ensemble of state-of-the-art ash dispersion models: towards probabilistic forecasts to increase the resilience of air traffic against volcanic eruptions | Other studies and data | 2021 |
| A Way Around the Volcanic Ash Cloud | Background | 2016 |
| The 2010 Volcanic Ash Cloud and Its Financial Impact on the European Airline Industry | Background | 2010 |
The community around it
No one has added to this page yet. Firsthand experience, a newer study or a different reading of the numbers would show up here, credited to you.
The full explanation
Evidence-backed AI-prepared starting mapVolcanic ash threatens aircraft mainly through jet engines: ash melts in the hot turbine section and re-solidifies as glass on nozzles and blades, erodes compressor and turbine blades, and fouls fuel nozzles with carbon deposits. Together these can cause power loss, engine surge or flame-out; of the documented encounters reviewed, eight involved some loss of engine power, including a complete shutdown of all four engines on a Boeing 747, though no crashes have been attributed to ash. Even low-concentration ash and aerosols accelerate wear on engines and components, leading to premature replacement. Because busy air corridors pass over or downwind of hundreds of explosive volcanoes, ash hundreds of miles from an eruption can still be hazardous, and eruptions can disrupt aviation globally.12
- Evidence 20
What it means for you
Which fits you?
Pick the situation closest to yours. Each answer says what it rests on.
If you are flying near or downwind of an active volcano
expect that ash can reach your route even hundreds of miles from the eruption, since busy corridors pass near many explosive volcanoes.2
Evidence-backedIf your flight is near an ash cloud but outside the highest concentrations
route optimization using ash-concentration quantile maps may allow the flight to proceed around the hazard rather than be cancelled.3
Evidence-backedIf an eruption is in its early phase and observations are limited
forecasts rest on probabilistic model ensembles, so treat the ash extent as uncertain rather than fixed.3
Evidence-backedIf a flight is scheduled during an ash event
be prepared for short-notice postponement or cancellation, and for questions about whether the destination airport will be ash-free and whether landing clearance will be given.4
Evidence-backedIf an aircraft is suspected of having flown through ash
an engine inspection with borescope should follow, with particular attention to the turbine cooling system, because some blockages leave no visible trace.1
Evidence-backedThe full story · 3 chapters
How do volcanic eruptions disrupt air travel, and how are flight paths rerouted around ash clouds?
Chapter 1: How ash damages aircraft and engines
AI summary:Ash melts into glass inside engines, erodes blades and fouls nozzles, risking power loss, and even low concentrations quietly wear parts.
Evidence-backed: Ash is not just a visibility problem. In the engine, ash drawn into the hot section melts and then solidifies as glass on turbine nozzles and blades, erodes compressor and turbine blades, and forms carbon deposits on fuel nozzles. The combination can push an engine to surge and flame out; restart may be possible after a flame-out. High-concentration clouds can also diminish visibility and damage flight control systems.12
Evidence-backed: Lower concentrations matter too. Encounters with low-concentration ash and aerosols accelerate wear on engines and aircraft components, resulting in premature replacement. Some damage is silent: under some conditions no sign of ash is evident and a turbine cooling-system blockage could go unnoticed until an engine inspection. Aircrew procedures exist for suspected ash encounters, and the recommended response includes an engine inspection with borescope, with particular attention to the turbine cooling system.12
Evidence-backed: The exposure is structural, not rare. Busy air traffic corridors pass over or downwind of hundreds of volcanoes capable of hazardous explosive eruptions; in the United States alone, aircraft carry about 300,000 passengers and hundreds of millions of dollars of cargo near active volcanoes each day. Ash can be a serious hazard even hundreds of miles from an eruption.2
This part rests on
1. Assessment and Characterization of Volcanic Ash Threat to Gas Turbine Engine Performance
Of these, eight resulted in some loss of engine power, including a complete shutdown of all four engines on a Boeing 747. However, no crashes have been attributed to volcanic ash. The major forms of engine damage caused by volcanic ash are: (1) deposition of ash on turbine nozzles and blades due to glassification (2) erosion of compressor and turbine blades (3) carbon deposits on fuel nozzles. The combination of these effects can push the engine to surge and flame out. If a flame out occurs, engine restart may be possible. Less serious engine damage can also occur. In most cases the major damage will require an engine overhaul long before the minor damage becomes an operational issue, but under some conditions no sign of volcanic ash is evident and the turbine cooling system blockage could go unnoticed until an engine inspection is performed. Several organizations provide aircrew procedures to respond to encounters with a volcanic ash cloud. If a volcanic ash encounter is suspected, then an engine inspection, including borescope, should be performed with particular attention given to the turbine cooling system.Read original source
2. Airborne volcanic ash; a global threat to aviation
The world's busy air traffic corridors pass over or downwind of hundreds of volcanoes capable of hazardous explosive eruptions. The risk to aviation from volcanic activity is significant - in the United States alone, aircraft carry about 300,000 passengers and hundreds of millions of dollars of cargo near active volcanoes each day. Costly disruption of flight operations in Europe and North America in 2010 in the wake of a moderate-size eruption in Iceland clearly demonstrates how eruptions can have global impacts on the aviation industry. Airborne volcanic ash can be a serious hazard to aviation even hundreds of miles from an eruption. Encounters with high-concentration ash clouds can diminish visibility, damage flight control systems, and cause jet engines to fail. Encounters with low-concentration clouds of volcanic ash and aerosols can accelerate wear on engine and aircraft components, resulting in premature replacement. The U.S. Geological Survey (USGS), in cooperation with national and international partners, is playing a leading role in the international effort to reduce the risk posed to aircraft by volcanic eruptions.Read original source
2 independent sources
- Ash drawn inAsh enters the engine intake
- Melts in hot sectionAsh melts in the hot turbine section
- Glass on nozzles and bladesIt re-solidifies as glass on turbine nozzles and blades
- Erosion and depositsBlades erode and carbon deposits foul fuel nozzles
- Power loss riskSurge, flame-out or loss of engine power
Drawn from this chapter's text
Chapter 2: Detecting and forecasting ash clouds
AI summary:Ensembles of dispersion models forecast ash location and load well but underestimate 3D concentrations, so forecasts carry uncertainty.
Evidence-backed: Forecasting is done with ensembles of ash dispersion models. In one evaluation, an a priori ensemble gave useful probability information in the early phase of an eruption when observational evidence is limited, but scored lower against observations than a second ensemble. The second ensemble's ash column load and horizontal location compared well with satellite observations, while its 3D ash concentrations were negatively biased, possibly because vertical ash distribution was too diluted in all model runs.3
Evidence-backed: For air traffic management, the useful output is horizontal maps of ash concentration quantiles (median, 75th and 99th percentiles) on a fine flight-level grid. These maps can support route optimization in areas where ash does not pose a direct and urgent threat; cost-optimized use of such hazard information is projected to reduce cancellations, reroutings and traffic-flow congestion.3
Evidence-backed: Research has also combined flight trajectories with modelled ash concentration data to analyse recent encounters, part of work on how ash affects aircraft navigation and communication systems.5
Chapter 3: Rerouting, delays and cancellations
AI summary:Eruptions shrink usable airspace, forcing short-notice choices on postponement, circling, destination conditions and air traffic control clearance.
Evidence-backed: An eruption heavily restricts the usable airspace around it, so the remaining free airspace has to be used efficiently to limit the impact on airlines and passengers. The practical questions are immediate: whether a flight must be postponed or cancelled at short notice, whether the ash cloud can be circled or is expanding the other way, whether the destination airport will be ash-free on arrival, and whether air traffic control will clear a landing at all. Simulation work has aimed to identify why ash leads to cancellations or delays and to develop action strategies, with the goal of operating as many flights as possible while making the best decision on whether a flight should go.4
Evidence-backed: The 2010 eruption of Eyjafjallajokull disrupted European air traffic heavily and demonstrated that a moderate-size Icelandic eruption can have global impacts on the aviation industry. Economic analysis of that event focused on effects on the airline industry and on potential gainers such as alternative transport industries.62
Add a source or a different interpretation
What would strengthen or challenge this answer?
Your contribution joins the discussion. Changes to the shared answer are reviewed separately.
Your turn
Where do you stand?
The conversation starts here
A few questions from this page to take the topic further. Bring a source, another angle or something you've tried.
3 open questions
- ResearcherLooks for evidenceFrom this page
The page says dispersion models underestimate 3D ash concentrations, but doesn't say what evidence would settle how much that bias matters for flight decisions. What data would you want to see to close that gap?
- ChallengerTests an assumptionFrom this page
The page notes no crashes have been attributed to ash, yet describes engine power loss and flame-out. In what situations might that reassuring framing not hold for judging flight safety?
- ExplorerInvites experienceFrom this page
The page mentions some turbine-cooling blockages leave no visible ash trace until inspection. If you've followed ash-and-aviation cases, what inspection or detection detail would you want to understand next?
Did this answer your question?
Be the first to voteMore quick questions: how you feel, and questions from connected pages
How do you feel about this?
No votes yetQuick questions from connected pages
Keep exploring
Where this leads
How does a volcanic eruption affect air travel and how are flight paths rerouted?You are here
One finding can inform several topics. Connections and subtopic reports are shown for exploring; they aren't extra evidence for this page.
Before you go
What to remember
Try to recall each hidden figure before you reveal it. Remembering, not rereading, is what makes it stick.
Dispersion-model ensembles forecast ash location and column load reasonably well but underestimate D concentrations, so forecasts carry real uncertainty.
Ash damages engines by glassifying on turbine parts, eroding blades and fouling fuel nozzles, which can cause power loss, surge or flame-out; no crashes have been attributed to ash.
Even low-concentration ash accelerates component wear and can cause damage that is invisible until inspection.
Your reading
0 of 3 chaptersThis answer keeps changing
When new evidence or a better source comes in, this page is updated (it's on version 2, last changed 2 hours ago). Follow it to be told when that happens.
Up nextHow does wildfire smoke and haze affect air quality and health?How does wildfire smoke and haze affect air quality and human health?Ask this Sylo
Still wondering about something?
Answers come only from this page's reviewed material, with citations, and say plainly when the page doesn't cover it yet.
Follow the story
This page changes as sources and experiences are reviewed. Follow it, share it or add what you know.
Behind this page
Who's adding to it, where it comes from, how it changed and what would make it better. Always open to everyone.
Discussion
Sources
Numbers match the citations in the article. A working link isn't proof that a page supports a claim; check the quoted passage and date.
- 1Assessment and Characterization of Volcanic Ash Threat to Gas Turbine Engine PerformanceJournal of Engineering for Gas Turbines and Power (Davison & Rutke)Published Feb 12, 2014Checked Oct 18, 2026
“Of these, eight resulted in some loss of engine power, including a complete shutdown of all four engines on a Boeing 747. However, no crashes have been attributed to volcanic ash. The major forms of engine damage caused by volcanic ash are: (1) deposition of ash on turbine nozzles and blades due to glassification (2) erosion of compressor and turbine blades (3) carbon deposits on fuel nozzles. The combination of these effects can push the engine to surge and flame out. If a flame out occurs, engine restart may be possible. Less serious engine damage can also occur. In most cases the major damage will require an engine overhaul long before the minor damage becomes an operational issue, but under some conditions no sign of volcanic ash is evident and the turbine cooling system blockage could go unnoticed until an engine inspection is performed. Several organizations provide aircrew procedures to respond to encounters with a volcanic ash cloud. If a volcanic ash encounter is suspected, then an engine inspection, including borescope, should be performed with particular attention given to the turbine cooling system.”
- 2Airborne volcanic ash; a global threat to aviationFact sheet (Neal & Guffanti)Published Jan 1, 2010Checked Oct 18, 2026
“The world's busy air traffic corridors pass over or downwind of hundreds of volcanoes capable of hazardous explosive eruptions. The risk to aviation from volcanic activity is significant - in the United States alone, aircraft carry about 300,000 passengers and hundreds of millions of dollars of cargo near active volcanoes each day. Costly disruption of flight operations in Europe and North America in 2010 in the wake of a moderate-size eruption in Iceland clearly demonstrates how eruptions can have global impacts on the aviation industry. Airborne volcanic ash can be a serious hazard to aviation even hundreds of miles from an eruption. Encounters with high-concentration ash clouds can diminish visibility, damage flight control systems, and cause jet engines to fail. Encounters with low-concentration clouds of volcanic ash and aerosols can accelerate wear on engine and aircraft components, resulting in premature replacement. The U.S. Geological Survey (USGS), in cooperation with national and international partners, is playing a leading role in the international effort to reduce the risk posed to aircraft by volcanic eruptions.”
- 3An ensemble of state-of-the-art ash dispersion models: towards probabilistic forecasts to increase the resilience of air traffic against volcanic eruptionsNatural hazards and earth system sciences (Plu et al.)Published Oct 5, 2021Checked Oct 18, 2026
“The a priori ensemble gives valuable information about the probability of ash dispersion during the early phase of the eruption, when observational evidence is limited. However, its evaluation with observational data reveals lower quality compared to the second ensemble. While the second ensemble ash column load and ash horizontal location compare well to satellite observations, 3D ash concentrations are negatively biased. This might be caused by the vertical distribution of ash, which is too much diluted in all model runs, probably due to defaults in the a posteriori source term and vertical transport and/or diffusion processes in all models. Relevant products for the air traffic management are horizontal maps of ash concentration quantiles (median, 75 %, 99 %) at a fine-resolved flight level grid. These maps can be used for route optimization in the areas where ash does not pose a direct and urgent threat to aviation. Cost-optimized consideration of such hazards will result in much less impact on flight cancellations, reroutings, and traffic flow congestions.”
- 4A Way Around the Volcanic Ash Cloudelib (German Aerospace Center) (Schmitt)Published Mar 1, 2016Checked Oct 18, 2026
“Will the flight have to be postponed or cancelled on short notice? Can the ash cloud be circled, or is it expanding in the opposite direction? Will the destination airport be ash-free upon arrival? Will the air traffic controllers give clearance for landing at all? \nThe DLR project ‘Volcanic ash impact on the Air Transport System’ (VolcATS) examines the issue of volcanic ash, its effects on air traffic and possible solutions to these problems. The ash spewed into the air during a volcanic eruption heavily restricts the surrounding air space that is usable for air traffic. The free air space must then be used efficiently to minimise the negative impacts on both the airlines and the passengers. DLR researchers in Braunschweig have used different simulations to identify the reasons for flight cancellations or delays due to volcanic ash and have developed action strategies for better handling problems encountered as a result of ash clouds. The aim is to carry out as many flights as possible and to assist in making the best decision possible about whether or not flights should be conducted.”
- 5Recent Encounters of Aircraft with Volcanic Ash Cloudselib (German Aerospace Center) (Christmann et al.)Published Oct 22, 2015Checked Oct 18, 2026
“Within the DLR internal project VolcATS -Volcanic Ash Impact on the Air Transport System, the DLR Institute of Flight Systems investigates the impact of volcanic ash on aircraft systems, especially on navigation and communication systems.In order to get a general overview of recent encounters of aircraft with volcanic ash clouds and possible damages to the aircraft, a compilation of known incidents from 2010 through 2014 was created in collaboration with the U.S. Geological Survey (USGS).Together with the DLR Institute of Flight Guidance, a more detailed analysis was performed by combining both flight trajectories and modeled volcanic ash concentration data.This paper gives an overview of the performed activities and future work.”
- 6The 2010 Volcanic Ash Cloud and Its Financial Impact on the European Airline IndustryRePEc: Research Papers in Economics (Mazzocchi et al.)Published Jan 1, 2010Checked Oct 18, 2026
“Last April, European air traffic was heavily disrupted by the volcanic ash cloud generated by the eruption of the Icelandic volcano Eyjafjallajokull. A (partial) shortcut to the all but impossible task of estimating all those impacts is an analysis of financial markets. In this paper, we will provide a first basic estimate of some of the economic effects of the Eyjafjallajokull volcano’s eruption, focusing on the airline industry, together with some evaluations of potential gainers, namely alternative transport industries.”
How it changed
Published 1 time since Oct 18, 2026.
- Version 2Oct 18, 2026Live now
AI-prepared Starting Map from live research.
- First published version.
Help improve it
The brief is open about what's uncertain. These are the specific gaps that new material would fill.
Open questions
What ash-concentration thresholds do airlines and air traffic control actually use to decide between flying, rerouting and cancelling?
No answers yet
How much would reducing the negative bias in modelled 3D ash concentrations change rerouting and cancellation decisions?
No answers yet
What were the quantified costs of the 2010 disruption to airlines, and how do they compare with the cost of precautionary cancellations?
No answers yet
How much long-term engine wear results from repeated low-concentration ash encounters, and how is it detected before failure?
No answers yet
Explore how this topic connects
Narrower questions connect to broader Sylos. Explore their findings, sources and the people contributing to each.