Volcanic ash strands thousands as Indonesia shuts airports

Volcanic ash from Indonesia’s Anak Krakatau has triggered widespread flight cancellations and delays across the country, leaving hundreds of thousands of passengers stranded as airports grapple with rapidly changing ash forecasts.

Airports closed as ash cloud spreads over western Indonesia

Indonesia’s main international gateway, Soekarno-Hatta International Airport serving Jakarta, suspended operations after a major eruption at Anak Krakatau in the Sunda Strait sent ash drifting across key flight corridors. Published coverage indicates that airspace closures were extended into Monday, September 7, with eight airports affected across western Indonesia.

Reports indicate that airport suspensions and route changes have left large numbers of passengers unable to depart or arrive. International and domestic services into Jakarta, nearby Halim Perdanakusuma, Lampung’s Radin Inten II and several regional airports were either cancelled or diverted as aviation authorities responded to evolving ash advisories. According to multiple news outlets, hundreds of flights were halted on Sunday alone, with disruptions continuing into the new week.

Indonesia’s Meteorology, Climatology and Geophysics Agency (BMKG) reported volcanic ash reaching up to around 15,000 feet over parts of western Java and Sumatra on Monday morning, moving westward over the Indian Ocean. Aviation notices and ash-related messages show that ash layers have been tracked over a broader vertical range above the region, prompting caution for aircraft routing even where airports remain technically open.

Air navigation updates indicate that the ash situation is also being monitored in connection with activity at Mount Ibu in North Maluku, although the most severe travel disruption is currently concentrated in the corridors linked to Anak Krakatau.

Hundreds of flights cancelled and diverted, with knock-on delays

According to international and regional news agencies, the Anak Krakatau eruption has led to the cancellation or delay of more than a thousand flights system-wide since Sunday, with Jakarta absorbing a particularly heavy impact. Published estimates from different outlets suggest that at least 170,000 passengers were stranded on the first full day of disruption, with total numbers expected to rise as airlines work through backlogs.

At Soekarno-Hatta alone, publicly available figures from regional wire services indicate that tens of thousands of travelers have been affected by cancellations and prolonged delays, while additional passengers remain stuck at secondary airports awaiting replacement flights. Some services have been re-routed to Kertajati Airport in West Java, where travelers are continuing their journeys overland by bus and Indonesia’s high-speed "Whoosh" rail line.

Low-cost and full-service carriers alike have been forced to adjust schedules. Updates from airline statements show that AirAsia and members of Indonesia’s Lion Air Group have cancelled or consolidated multiple domestic and regional flights as part of a broader safety-first approach in affected airspace. In eastern Indonesia, separate but related disruptions have also been reported in recent days following ash emissions from Mount Lewotolok in East Nusa Tenggara, further complicating operational planning.

Even where airports have remained open, the need to detour around ash plumes has added time and complexity to flight paths, increasing fuel requirements and reducing aircraft and crew availability for later rotations. Aviation planning specialists note that this often leads to cascading delays well beyond the immediate zone of the eruption.

Passengers face long waits, changing itineraries and limited options

The closures have left terminals crowded with passengers trying to rebook or reroute journeys. Media coverage and social media posts from travelers describe long queues at airline desks in Jakarta and other hubs, with many passengers told to return home or to their hotels while new schedules are prepared.

Australian and regional travelers have been among those heavily affected, with national broadcasters in Australia reporting that flights between Jakarta and Australian cities were cancelled on Monday, stranding visitors in Indonesia and delaying those attempting to transit through Jakarta. Several foreign carriers have issued online travel alerts and waived rebooking fees for passengers scheduled to fly to or from Indonesia during the disruption window.

In some cases, travelers heading to or from other Southeast Asian hubs such as Singapore have been advised through public forums and local media to consider alternative routings via Surabaya, Batam or other airports that remain less affected by ash. Others have shifted to sea transport on Indonesian ferries or domestic rail where possible, trading speed for certainty in the face of ongoing flight suspensions.

Travel advisories from consular services and airlines generally encourage passengers to check flight status before leaving for the airport, monitor official airport and airline channels, and build in extra flexibility on dates and connections in case of further ash-related changes.

Aviation safety drives conservative response to volcanic ash

Indonesia sits along the Pacific “Ring of Fire” and experiences frequent volcanic activity, which can pose a serious risk to aircraft. Industry and regulatory guidance highlight that volcanic ash can damage jet engines, abrade cockpit windows and interfere with onboard instruments, even when ash is not visible to the naked eye from the cockpit.

International aviation bodies and Indonesian regulators have, over recent decades, adopted a more conservative posture around ash clouds, particularly since a series of documented encounters, including a well-known 1982 incident near Jakarta in which a British Airways Boeing 747 temporarily lost all four engines after flying through an ash cloud. That historical case, detailed in aviation safety records, underlines why airspace managers now act quickly when satellite data and pilot reports indicate ash at cruising altitudes.

Current ash advisories issued by Indonesia’s air navigation service show close coordination with meteorological monitoring, including special volcanic ash messages that map the altitude, movement and expected dissipation of ash plumes. These advisories guide decisions on airport closures, flight level restrictions and the creation of temporary ash avoidance routes.

The approach means that even moderate eruptions can lead to large-scale, short-term disruption, particularly where major hubs and busy regional corridors lie downwind of a volcano. However, aviation planners argue that the cost of delays and cancellations is outweighed by the need to avoid engine damage or in-flight emergencies.

Uncertain timeline for full recovery of flight schedules

As of Monday, there is no clear timeline for the full resumption of normal flight schedules. Meteorological briefings indicate that ash from Anak Krakatau has begun to drift further over the Indian Ocean at higher levels, but low and mid-level concentrations remain under close watch near western Java and southern Sumatra.

Recent updates from Indonesian agencies suggest that airport closures and flight suspensions are being reviewed in rolling blocks of several hours, using the latest satellite imagery and ash dispersion models. Some airports are expected to reopen in stages as conditions allow, yet airlines will likely need additional time to reposition aircraft and crew, and to clear passenger backlogs.

Travel industry analysts note that, even after airspace fully reopens, passengers may continue to face schedule changes for several days, as aircraft are not always in their planned locations and maintenance windows may need adjustment. Carriers operating dense regional networks are especially vulnerable to such knock-on effects.

For now, publicly available information from airports, airlines and meteorological services points to a cautious, conditions-based approach. Travelers planning to transit Indonesia in the coming days are being advised to stay informed through official online channels, consider flexible tickets where possible, and prepare for the possibility of last-minute adjustments while Anak Krakatau remains active.

Al Jazeera: Anak Krakatau eruption shutters Indonesian airports

AP News: Volcanic island in Indonesia erupts, canceling flights

The Guardian: Volcano eruption in Indonesia leaves travellers stranded

ABC News: Australians stranded as volcanic ash closes Jakarta airport