Volcanic ash from Anak Krakatau strands travellers across Indonesia

Thousands of air travellers across Indonesia and the wider region remain stranded after ash from the erupting Anak Krakatau volcano forced the closure of multiple airports and the cancellation of hundreds of flights.

Airports closed as ash cloud spreads over western Indonesia

Flight operations at Indonesia’s main international gateway, Soekarno-Hatta International Airport near Jakarta, have been suspended repeatedly since Sunday after monitoring networks detected volcanic ash from Anak Krakatau drifting over key air corridors. Publicly available information from Indonesia’s air navigation service and transport authorities indicates that at least seven to eight airports, including Jakarta’s secondary Halim Perdanakusuma and Bandung’s Husein Sastranegara, have faced full or partial closures as ash moved across western Java and southern Sumatra.

Reports compiled by international and regional media estimate that around 170,000 travellers were stranded on Sunday alone as airlines halted departures and diverted or cancelled arrivals. Subsequent updates on Monday suggest the disruption has extended into a second day, with notices to air missions extending closures at several airports into the evening and beyond.

The ash cloud followed a series of eruptions at Anak Krakatau over the weekend, with Indonesia’s meteorological agency cited as reporting ash reaching altitudes of up to 6,000 metres over Java and significantly higher over parts of Sumatra. Aviation advisories show that the drifting plume has periodically crossed major domestic and international flight paths, making it unsafe to operate jets through affected airspace.

Indonesia sits on the seismically active Pacific Ring of Fire and experiences frequent volcanic activity, but the current disruption stands out for its impact on the country’s busiest aviation hub and on regional connections linking Southeast Asia and Australia.

Passengers face long waits, missed connections and scarce alternatives

Scenes from Jakarta’s Soekarno-Hatta and other affected airports show passengers queueing at airline counters, sleeping in terminal seating and searching for scarce rebooking options. Coverage from regional broadcasters describes snaking lines at ticket desks as travellers attempt to secure new itineraries, refunds or accommodation after last-minute cancellations.

Some international passengers bound for Jakarta have found themselves turned around at origin airports or left waiting on uncertain departure boards. Reports from Singapore’s Changi Airport indicate that travellers arriving to check in for flights to Jakarta discovered only at the terminal that their services had been grounded due to the evolving ash advisories.

Australian media describe tourists and business travellers stuck in Jakarta and other Indonesian cities following the cancellation of flights to and from major Australian gateways. Several carriers have published travel waivers for affected dates, allowing passengers to defer trips or convert bookings to credits without additional fees, but near-term seat availability remains limited as airlines work through the backlog.

For domestic travellers, alternative routes are proving difficult. Overland journeys between key cities can require many hours or overnight travel, while ferry and inter-island shipping options are constrained by capacity and schedules. Travel forums and social media posts suggest some passengers are weighing long detours through unaffected airports in eastern Indonesia or neighbouring countries to continue their journeys.

Regional ripple effects reach Singapore and beyond

Although the ash is concentrated over western Indonesia, the impact has spread across the region. Flight data and airport statements show that links between Jakarta and Singapore have been among the hardest hit, disrupting one of Southeast Asia’s busiest short-haul routes. Airlines operating between Soekarno-Hatta and Changi have cancelled or severely reduced services while the ash cloud remains over key approach paths.

Singapore-based news outlets report that some travellers to Indonesia’s capital are now considering rerouting via alternative Indonesian cities or delaying trips entirely. At Changi, assistance counters have reported heavy demand as passengers seek to rebook onto later flights or change destinations.

The disruption is also affecting longer-haul itineraries using Jakarta as a transfer point. Travellers connecting between Australia, Southeast Asia and the Middle East through Indonesia’s main hub have reported missed onward flights and unplanned overnight stays. Aviation analysts quoted in international coverage note that even as airports reopen, schedules may remain unsettled for several days while aircraft are repositioned and crews return to normal rotations.

Other regional hubs are monitoring the situation closely. While direct closures outside Indonesia have so far been limited, airlines operating routes that pass near the ash cloud have adjusted flight paths and altitudes in coordination with air traffic control and volcanic ash advisory centres.

Safety protocols keep jets grounded while ash remains in the air

Volcanic ash presents a well-documented hazard to aircraft. Aviation safety guidance notes that fine ash particles can melt inside jet engines, adhere to turbine components and impair airflow, potentially leading to significant damage or engine failure. The particles can also abrade cockpit windows and airframe surfaces and reduce visibility around busy airports.

In Indonesia’s current situation, air navigation authorities have issued advisories and restricted airspace along the projected path of the ash cloud based on satellite imagery, ground observations and meteorological modelling. Notices indicate that closures will remain in place until monitoring confirms that ash concentrations have fallen to safe levels over runways and approach corridors.

Airlines operating in the region are required to follow these advisories and to apply their own internal risk assessments, which typically err on the side of caution. Industry practice in similar events has been to gradually restart operations with limited flights once conditions improve, while maintaining wide routing margins around any remaining ash plumes.

Experts quoted in previous international incidents involving volcanic ash caution that, despite the inconvenience, grounding aircraft is considered a necessary measure to avoid catastrophic damage aloft. In Indonesia, aviation and geological agencies continue to track Anak Krakatau’s activity, warning that further eruptions remain possible even if visible ash temporarily subsides.

What travellers can expect in the coming days

With Anak Krakatau still active and ash advisories in effect, aviation observers suggest that disruption could continue intermittently over the coming days. The timing of a full return to normal schedules will depend on both volcanic activity and prevailing winds, which influence the direction and density of ash over flight routes.

Airports and airlines are urging passengers to check flight status before leaving for the airport and to rely on official airline and airport channels for updates. Several carriers have expanded fee waivers and flexible rebooking policies for tickets issued before the eruption, particularly on routes touching Jakarta and other affected airports.

Even once flight operations resume, travellers should be prepared for residual delays as airlines clear the backlog of stranded passengers and reposition aircraft. Industry analysts point out that aircraft and crew are currently out of place across multiple cities, a mismatch that can take several days to resolve even under stable weather and operating conditions.

Travel planners recommend allowing extra connection time for itineraries involving Indonesia and neighbouring hubs this week and considering travel insurance or flexible fares for trips scheduled while Anak Krakatau’s activity remains elevated.

Associated Press: Volcanic island in Indonesia erupts, canceling hundreds of flights

Al Jazeera: Thousands stranded as Anak Krakatau eruption shutters Indonesian airports

CNA: Jakarta airport suspends flights due to Mount Anak Krakatau ash

ABC News: Flights cancelled leaving Australians stranded as volcanic ash closes Indonesian airports