Jakarta airports reopen as Anak Krakatau ash clears, but flight recovery lags

All eight Indonesian airports that were temporarily closed due to volcanic ash from Mount Anak Krakatau, including Jakarta's main international gateway Soekarno-Hatta International Airport, resumed operations on the morning of Sept 8. The reopening ends a three-day disruption that affected nearly 3,000 flights and about 341,000 passengers, but airlines now face a significant backlog as they work to restore normal schedules.

Soekarno-Hatta International Airport reopened at 12.30am local time, followed by Halim Perdanakusuma airport at 12.40am, according to Notices to Airmen (Notams) issued by state-owned air navigation operator AirNav Indonesia. The swift reopening reflects improving conditions, with the Meteorology, Climatology and Geophysics Agency (BMKG) reporting that paper tests at all eight airports were negative for volcanic ash as of 6am.

What caused the airport closures and how many passengers were affected?

Anak Krakatau, located in the Sunda Strait between Java and Sumatra, began erupting on Sept 4. Volcanic ash spread towards Jakarta, forcing the temporary closure of Soekarno-Hatta and several other airports. Coordinating Infrastructure and Regional Development Minister Agus Harimurti Yudhoyono said during a visit to Soekarno-Hatta on Sept 7 that 2,961 domestic and international flights and approximately 341,000 passengers had been affected over the previous three days.

Some passengers were stranded at airports while others were forced to cancel their journeys entirely. Agus confirmed that passengers whose flights were cancelled are entitled to full refunds, including those who booked through online travel agents. Free buses and trains are being provided for passengers diverted through alternative airports to help them continue their journeys.

How are airlines managing the flight backlog?

Singapore Airlines announced on Sept 8 that it is adding eight relief flights between Singapore and Jakarta to move passengers affected by the disruption, subject to seat availability. Affected passengers will be progressively rebooked on the next available flights as services resume. However, disruptions continued, with one Jakarta-Singapore flight cancelled and six services between the two cities retimed on Sept 8.

Aviation analysts caution that even with airports open, flight schedules may take time to return to normal. A prolonged closure can leave both aircraft and crews in incorrect locations, while crew duty-hour limits and the need to rebook displaced passengers can further slow the recovery process.

When an airport is opened, it means that operationally the airport can be used, but it does not necessarily mean that all flights will immediately return to normal. Recovery of the flight network can take several hours or even longer.

Polana Pramesti, an analyst with the Indonesian Aviation Association, made these remarks to The Straits Times on Sept 7, underscoring the complexity of restoring a disrupted aviation network.

Is Anak Krakatau still erupting?

Anak Krakatau remains active, with a small eruption recorded at 7.49am on Sept 8 that lasted 19 seconds. However, BMKG said volcanic and related activity has declined compared with previous days. At 9am, volcanic ash was being monitored at altitudes of up to 7,000 feet (2.13km), moving south to south-west towards north-western Banten and the Indian Ocean. This is a significant reduction from Sept 7, when ash was detected as high as 50,000 feet (15.24km).

Authorities continue to monitor the movement of volcanic ash to ensure flights can operate safely. AirNav said it will issue further aviation updates as conditions change.

What is Indonesia doing to prepare for future disasters?

President Prabowo Subianto said on Sept 7 that the Anak Krakatau eruption, a recent earthquake in Flores and continuing forest fires demonstrate that Indonesia needs to significantly increase spending on disaster mitigation and prepare equipment before emergencies strike.

This is our destiny - a country that lies in the Ring of Fire. This means we must be prepared to face situations like these at all times.

Prabowo ordered officials to draw up a comprehensive disaster mitigation master plan, including more helicopters, water pumps, fire engines and excavators, as well as aircraft for weather modification and drones capable of dropping water.

We must prepare to deal with and mitigate disasters. Do not wait until they happen. We must prepare long beforehand.

The government's focus on proactive disaster preparedness reflects a broader regional need for resilient infrastructure in the face of natural hazards, a priority that resonates with global efforts to build sustainable and adaptive systems.

What should affected passengers do now?

Passengers whose flights were cancelled are entitled to full refunds, including those who booked through online travel agents. Airlines are progressively rebooking affected passengers on the next available flights, and free buses and trains are available for those diverted through alternative airports. Passengers are advised to check with their airlines for the latest schedule updates as operations gradually return to normal.