Volcanic Ash & Aviation: From Galunggung to Today
Last updated: April 2026
BA009 — Galunggung Engine Failure at FL370
British Airways Flight 009, a Boeing 747, flew through an undetected ash cloud from Mount Galunggung over Indonesia. All four engines flamed out at FL370. The aircraft descended without power for approximately 16 minutes before the crew managed to restart engines at a lower altitude. All 263 people on board survived. The event was the first major demonstration that volcanic ash could cause total engine failure in jet aircraft.
Singapore Airlines 747 — Second Galunggung Encounter
Weeks after the BA009 incident, a Singapore Airlines Boeing 747 also encountered the Galunggung ash cloud and suffered damage to two engines. The twin events forced ICAO to begin developing volcanic ash warning procedures. The International Airways Volcano Watch (IAVW) was conceived as a result.
KLM 747 — Mount Redoubt, Alaska
KLM Flight 867, a Boeing 747-400, encountered an ash cloud from Mount Redoubt while descending into Anchorage. All four engines lost power. The crew restarted engines after descending from FL250 to approximately FL130 and landed safely. Repairs cost over $80 million. The event led directly to ICAO establishing the nine Volcanic Ash Advisory Centres (VAACs) in 1991.
Mount Pinatubo — Largest 20th-Century Eruption
The eruption of Mount Pinatubo in the Philippines was the largest volcanic event of the 20th century, injecting 20 million tonnes of sulfur dioxide into the stratosphere. Clark Air Base and Cubi Point Naval Air Station were permanently evacuated. Ash clouds disrupted aviation across Southeast Asia for weeks. At least 20 aircraft sustained ash damage. The event validated the newly established VAAC system and proved the need for satellite-based ash detection.
Eyjafjallajokull — European Airspace Paralysis
The eruption of Eyjafjallajokull in Iceland produced a sustained ash plume that drifted across Northern and Central Europe. Between April 15-20, airspace was closed in 23 European countries. Over 100,000 flights were cancelled and approximately 10 million passengers were stranded. The total economic impact was estimated at $1.7 billion to airlines and $5 billion to the wider economy. The event revealed that the existing zero-tolerance ash policy was untenable and led to the adoption of the three-zone ash concentration model (low / medium / high contamination), giving airlines the option to operate in areas of low ash concentration with appropriate risk assessment.
Grimsvotn — Testing the New Framework
Iceland's Grimsvotn volcano erupted with a plume reaching 20 km altitude — higher than Eyjafjallajokull. However, the newly implemented three-zone ash model limited the disruption to approximately 900 cancelled flights, primarily in Iceland and Scotland. The eruption served as a real-world validation of the post-Eyjafjallajokull response framework.
Mount Kelud — Indonesian Airspace Disruption
Mount Kelud erupted explosively, sending ash to 17 km altitude. Seven Indonesian airports were closed, including major hubs at Surabaya, Yogyakarta, and Solo. The Darwin VAAC issued advisories affecting routes between Australia and Southeast Asia. The eruption lasted only hours but demonstrated the vulnerability of the busy Indonesian domestic network to volcanic events.
Raikoke — North Pacific Ash Cloud
Raikoke volcano in the Kuril Islands erupted after 95 years of dormancy, producing an ash plume that reached 13 km and drifted across the busy North Pacific air routes (NOPAC tracks). The Anchorage and Tokyo VAACs coordinated advisories. Several trans-Pacific flights were rerouted. The eruption highlighted ongoing risks on the busiest long-haul corridor in the world.
Hunga Tonga — Stratospheric Injection and Shockwave
The eruption of Hunga Tonga-Hunga Ha'apai was the most powerful volcanic event since 1883 (Krakatoa). The plume reached 58 km altitude — the highest ever recorded — penetrating the mesosphere. The atmospheric shockwave circled the globe multiple times and generated tsunami warnings across the Pacific. Nadi FIR (Fiji) and Auckland Oceanic were affected. The eruption injected 146 million tonnes of water vapor into the stratosphere, a volume with no modern precedent, raising questions about long-term atmospheric effects on high-altitude aviation.
Iceland Reykjanes Eruptions — Recurring Activity
A series of eruptions on the Reykjanes Peninsula near Keflavik International Airport created a persistent volcanic hazard. While the eruptions were primarily effusive (lava flows rather than explosive ash), SO2 emissions affected air quality and raised concerns about potential escalation to explosive activity. Grindavik was evacuated. The proximity to Iceland's primary international airport kept the aviation community on alert.
Mount Etna and Stromboli — Dual Eruption
Simultaneous heightened activity at Mount Etna and Stromboli in Italy led to temporary restrictions at Catania-Fontanarossa Airport and ash advisories across the central Mediterranean. The Toulouse VAAC issued multiple Volcanic Ash Advisories. While disruptions were limited, the dual-source scenario tested the response capability of European volcanic ash monitoring.
VAAC System Modernisation
The nine VAACs continued upgrading to higher-resolution dispersion models, improved satellite detection (including infrared and lidar), and more granular concentration forecasts. ICAO advanced work on the International Airways Volcano Watch roadmap, focusing on real-time ash concentration measurement and automated SIGMET generation. The goal: moving from binary avoidance to quantified risk, enabling operators to make data-driven routing decisions.
This timeline is for informational purposes only. Data sourced from ICAO, VAAC advisories, EASA, FAA, and publicly available aviation records. This content does not constitute safety advice, risk assessment, or operational guidance.