Indonesia has reopened all airports that were temporarily closed due to volcanic ash from Mount Anak Krakatau, restoring air connectivity after a major eruption disrupted thousands of flights and affected more than 340,000 travellers across western Indonesia.
According to The Business Times, volcanic ash from Anak Krakatau spread across Jakarta and surrounding areas following an eruption late on 4 September, forcing authorities to close eight airports as a precaution. Jakarta’s Soekarno-Hatta International Airport, the country’s main aviation gateway, resumed operations on 8 September after changing wind conditions cleared ash from the surrounding airspace.
Major Airports Return to Operation
The reopening brought significant relief to airlines and passengers after several days of cancellations, delays and diversions.
Six airports reopened on 8 September, while another had resumed operations the previous day, bringing all affected airports back online. These included facilities serving Jakarta, Bandung and other areas in western Indonesia.
Before reopening Soekarno-Hatta, authorities continued monitoring volcanic ash and weather conditions closely to ensure that aircraft could operate safely.
Transport Minister Dudy Purwagandhi said aviation authorities would also conduct airworthiness checks on 178 aircraft that had remained grounded at Soekarno-Hatta during the closure, meaning some schedules could take additional time to return fully to normal.
The gradual restoration reflects the aviation sector’s priority of balancing rapid recovery with passenger and aircraft safety.
More Than 340,000 Travellers Affected
The eruption generated one of Indonesia’s most significant aviation disruptions of the year.
By 7 September, approximately 341,000 people had been affected by delays, diversions or cancellations involving 2,961 flights, according to Indonesia’s Chief Infrastructure Minister Agus Harimurti Yudhoyono.
Soekarno-Hatta was particularly affected because of its role as Indonesia’s busiest international gateway and one of Southeast Asia’s most important aviation hubs.
The disruption also extended internationally. On 6 September, all 33 scheduled flights from Singapore to Jakarta had been cancelled by early evening, while Singapore Airlines and Scoot were among the carriers forced to suspend services because of the ash cloud.
The scale of the interruption demonstrates how volcanic activity in Indonesia can rapidly affect regional travel networks well beyond the immediate area surrounding an eruption.
Volcanic Ash Presents Serious Aviation Risks
Airport closures during volcanic eruptions are essential because ash can pose significant risks to aircraft.
Fine volcanic particles can reduce visibility and potentially interfere with aircraft systems, while ash drawn into jet engines can damage internal components.
During the Anak Krakatau eruption, satellite monitoring identified ash clouds spreading across parts of Jakarta, Banten, West Java, Lampung and Bengkulu, with some reaching elevations of up to approximately 15,000 metres.
Shifting winds further complicated the situation because the direction of the ash cloud could change quickly, forcing authorities to repeatedly reassess whether airports and flight paths remained safe.
This uncertainty led the government to extend airport closures several times before conditions improved sufficiently for operations to resume.
Airline Costs Rise During Prolonged Disruptions
The eruption also created significant financial pressure for Indonesia’s aviation industry.
Bayu Sutanto, Secretary General of the Indonesia National Air Carriers Association, estimated that airlines could lose as much as 19 billion rupiah, or around US$1 million, per day during such disruptions.
Costs can accumulate through cancelled flights, aircraft parking, crew arrangements and additional fuel required when flights are diverted.
Operational disruption also spreads quickly through airline networks. According to Bayu, a delay involving a single aircraft at Soekarno-Hatta can affect another three or four subsequent flights scheduled to use the same plane.
This interconnected nature of modern aviation means that even temporary closures can have continuing effects after an airport officially reopens.
Fresh Eruptions Keep Authorities on Alert
Although airports have reopened, Anak Krakatau remains active.
The volcano monitoring agency reported three additional eruptions on the morning of 8 September. These were smaller than previous eruptions, but officials warned that new ash emissions could still disrupt aviation depending on their height and prevailing wind direction.
Geological Agency head Lana Saria said authorities would continue monitoring developments closely because volcanic conditions remain dynamic.
Earlier assessments also indicated that although eruption frequency had increased, scientists could not precisely predict the timing, scale or type of future eruptions.
This means airlines and travellers may continue to face uncertainty even as normal operations gradually resume.
Search Continues for Missing Journalists and Crew
The eruption has also led to concerns beyond aviation.
A speedboat carrying five journalists and three crew members was reported missing in the Sunda Strait after the journalists had been covering Anak Krakatau’s activity. Indonesian rescue authorities deployed personnel and a rescue vessel to search for the eight missing people.
The incident highlights the broader dangers surrounding active volcanic zones, where rapidly changing weather, ash, marine conditions and eruption activity can create risks for nearby communities, emergency personnel and media workers.
Indonesia’s Geography Requires Constant Preparedness
Anak Krakatau is located in the Sunda Strait between Java and Sumatra and is among roughly 130 active volcanoes across Indonesia.
Indonesia lies along the Pacific Ring of Fire, where major tectonic plates meet and generate frequent earthquakes and volcanic activity.
Anak Krakatau itself emerged from the volcanic system associated with the historic Krakatau eruption of 1883. That eruption caused catastrophic destruction and tsunamis that killed more than 36,000 people. A separate collapse involving Anak Krakatau in 2018 also generated a deadly tsunami that killed more than 400 people.
The country’s geological setting means volcanic risk management remains an important part of national transport planning and disaster preparedness.
Aviation Resilience Becomes Increasingly Important
The latest disruption demonstrates why coordination between meteorological agencies, geological authorities, airport operators and airlines is critical.
During the closure, authorities provided airlines with alternative airports including Kertajati, Juanda and Semarang, allowing selected services to be diverted rather than cancelled entirely.
Such contingency measures are particularly important in Indonesia, where air transport plays a crucial role in connecting thousands of islands and supporting tourism, commerce and regional mobility.
Improved ash monitoring, faster communication and flexible flight-routing systems can help reduce disruption while maintaining the high safety standards required during volcanic events.
Looking Ahead
The reopening of all affected airports represents an important step towards restoring normal travel across western Indonesia, but authorities remain cautious as Anak Krakatau continues to show volcanic activity.
The episode illustrates the wider economic consequences that natural hazards can create. More than 340,000 passengers, thousands of flights and major domestic and international routes were affected within only a few days.
For Indonesia, strengthening aviation resilience will remain essential as the country continues expanding its tourism, business and transport networks.
The immediate priority is now to restore schedules safely while maintaining close monitoring of Anak Krakatau. Should further eruptions occur, rapid coordination between government agencies, airports and airlines will again be critical to protecting passengers while minimising disruption.
Indonesia’s response demonstrates how effective disaster preparedness increasingly depends not only on monitoring volcanic activity itself, but also on maintaining resilient transportation systems capable of adapting quickly when nature disrupts one of Southeast Asia’s busiest aviation networks.
