Volcanic Ash Grounds Singapore-Jakarta Flights and Strands Thousands — But Reopening the Airport Won’t End the Chaos

SINGAPORE/JAKARTA — One of Southeast Asia’s busiest international air corridors was thrown into chaos on Sunday after volcanic ash from Mount Anak Krakatau drifted into the airspace around Jakarta’s main airport, forcing flight operations to stop and leaving thousands of passengers stranded or scrambling for alternatives.

At Singapore’s Changi Airport, travelers arrived expecting to fly to Jakarta only to discover their flights had been cancelled.

In Jakarta, some passengers had already checked in, cleared immigration and reached their boarding gates before being told they could not leave.

The disruption was substantial.

Based on flight data covering 1.30am to 1.30pm on Sept. 6, 301 flights at Soekarno-Hatta International Airport were affected by cancellations, delays, diversions and other operational problems.

That included:

233 domestic flights,
58 international flights, and
10 cargo flights.

And although authorities were working toward reopening the airport, the consequences were likely to last far longer than the closure itself.

Because when a major hub stops operating for hours, simply reopening the runway does not instantly put every aircraft, crew and passenger back where they belong.

Changi was open — but Singapore-Jakarta flights were hit hard

This is an important accuracy point.

Singapore’s Changi Airport was not shut down because of volcanic ash.

Instead, flights between Singapore and Jakarta were cancelled because Soekarno-Hatta could not safely receive or dispatch aircraft.

Singapore Airlines’ official advisory listed 19 Singapore-Jakarta or Jakarta-Singapore services cancelled on Sept. 6, including flights scheduled from early morning through the evening.

Scoot separately cancelled 12 Jakarta services scheduled for Sunday, including flights TR274, TR275, TR276, TR277, TR308, TR309, TR278, TR279, TR272 and TR273, along with previously retimed services.

Taken together, the two Singapore carriers had more than 30 individual Singapore-Jakarta flight sectors listed as cancelled on Sunday.

That helps explain why large groups appeared at Changi despite the disruption occurring hundreds of kilometres away in Indonesia.

Some passengers received contradictory information

The human impact became especially visible because airline communications did not always match what passengers saw on booking apps.

CNA spoke with Singapore travelers who said they either did not receive cancellation information clearly or saw flight statuses that still appeared confirmed.

One passenger received a cancellation message from Scoot but was unsure whether it was legitimate because she had booked through Singapore Airlines and the booking reference did not match.

She checked the SIA app, saw the flight listed as “confirmed”, and went to Changi with her family anyway.

Another traveler said Singapore Airlines had not told him his flight was cancelled before he left for the airport.

SIA staff subsequently told him he could submit a claim for transportation costs incurred travelling to Changi, provided he kept his receipt.

The problem was not necessarily that airlines had no notification system.

SIA advises customers to keep their contact details updated and monitor flight-status alerts, while Scoot said it had contacted affected passengers and offered rebooking or refunds.

But rapidly changing airport closures can leave airline websites, partner-booking systems, texts and operational databases updating at different times.

For passengers standing at the departure hall, that technical explanation does little to reduce the frustration.

One pregnant passenger suddenly faced a medical deadline

Among the travelers stranded at Changi was 31-year-old Catrine Carina, who is seven months pregnant and had planned to return to Indonesia to give birth.

She and her husband arrived at the airport before learning their flight was among those grounded.

The delay created an extra complication: depending on when she eventually travels, she may need to obtain a new fit-to-fly medical certificate, since such documentation for pregnant passengers can have a limited validity window.

The couple had planned for her to remain in Indonesia until after the birth while her husband returned to Singapore after a week.

The volcano suddenly placed that schedule in doubt.

And they were far from alone.

Jakarta passengers were already past immigration when flights stopped

The situation at Soekarno-Hatta was even more chaotic.

Indonesian businessman Muhammad Akbar, 55, told CNA he had received his boarding pass, cleared immigration and reached the departure gate for a flight to Bangkok.

Only then was he told the service was cancelled and that passengers had to leave the secure departure area again.

Long queues formed inside the terminals as passengers attempted to:

rebook flights;

obtain refunds;

contact travel agents;

rearrange hotels;

change airport transfers;

and find alternative transport.

Some eventually sat or slept on terminal floors while waiting for information.

CNA reported that airport authorities arranged refreshments, rest areas and buses to hotels in coordination with airlines.

More than 22,000 passengers were caught in the disruption

Indonesia’s Transportation Ministry said more than 22,000 passengers had been affected during the earlier stages of the shutdown.

Associated Press later reported about 22,800 affected passengers, while warning that the total disruption could increase because flight cancellations create knock-on problems elsewhere in airline networks.

That is why the final number of disrupted journeys can exceed the number of flights cancelled during the closure itself.

An aircraft that fails to reach Jakarta cannot necessarily operate its next scheduled trip.

A pilot or cabin crew member can end up stranded away from the airport where they are supposed to begin another flight.

Connecting travelers miss onward services.

And passengers rebooked from one cancelled flight can fill seats that would otherwise have been available to travelers on later departures.

So even reopening the airport does not end the chaos

This is the part that may matter most for travelers.

CNA’s latest report said Soekarno-Hatta operations were slated to resume at 5.30pm Jakarta time, or 6.30pm Singapore time, after the shutdown had already been repeatedly extended.

But travelers should not interpret an airport reopening as meaning all cancelled flights automatically return to the schedule.

Singapore Airlines had already cancelled services scheduled well into Sunday evening, according to its official advisory.

Scoot also cancelled evening departures, including flights originally scheduled as late as 10.15pm from Jakarta.

That reflects the operational reality after a prolonged shutdown.

The airport may technically reopen while airlines still need hours—or potentially longer—to reposition aircraft, crews and passengers.

Why volcanic ash shuts airports even when the volcano is 150km away

Anak Krakatau is located in the Sunda Strait between Java and Sumatra, more than 150km from Soekarno-Hatta Airport.

So why stop hundreds of flights?

Because aircraft do not need to fly directly over the crater to be endangered.

Ash from the eruption was detected in airspace around Jakarta.

Indonesia’s meteorological authorities reported volcanic ash reaching approximately 6,000 metres on the Java side, while a plume on the Sumatra side reached as high as 15,000 metres, or roughly 50,000 feet.

Volcanic ash is particularly dangerous to aircraft.

Fine particles can be ingested into jet engines, where extreme temperatures can melt them into glass-like material capable of damaging engine components and potentially causing loss of thrust.

Ash can also damage windscreens, sensors and other aircraft systems.

That is why airlines and aviation authorities generally treat confirmed volcanic ash in flight corridors as a serious safety hazard rather than ordinary bad weather.

The eruption did not suddenly begin on Sunday

Anak Krakatau had already been showing renewed volcanic activity for months.

Indonesia’s Geological Agency says activity increased in June before the volcano erupted again on July 2.

Authorities raised its volcanic alert status from Level II to Level III, or Siaga, on July 2.

The warning remained in effect through this weekend.

By Sept. 5, the Geological Agency said the volcano had entered a period of continuous Strombolian eruption, characterized by glowing volcanic material and what resembled a sustained lava fountain.

Booming sounds and vibrations were reported across parts of Banten, West Java and Lampung.

Two further eruptions were recorded on Sunday, according to CNA and Indonesian authorities.

But officials say this does NOT mean a giant eruption is inevitable

Indonesia’s Geological Agency chief Lana Saria urged the public not to assume repeated eruptions automatically mean a dramatically larger eruption is coming.

The agency continues to monitor the volcano closely.

Authorities maintain a 3km exclusion zone around Anak Krakatau and have warned of hazards including:

lava flows;

hot volcanic material;

ashfall;

and potentially dangerous volcanic clouds.

That is different from predicting a catastrophic eruption.

And there was another important reassurance.

No tsunami warning was issued

The name Krakatau understandably raises fears far beyond aviation.

The original Krakatau eruption in 1883 generated catastrophic tsunamis and killed tens of thousands of people.

More recently, the partial collapse of Anak Krakatau in December 2018 triggered a tsunami around the Sunda Strait that killed more than 400 people.

But Indonesia’s Geological Agency said its latest assessment does not indicate that the volcano’s present structure is likely to undergo a collapse on a scale capable of generating a tsunami.

Authorities have told coastal residents in Banten and Lampung to remain calm while following official instructions.

Reuters also reported that no tsunami alert had been issued in connection with this weekend’s eruption.

That should be made explicit in coverage, because headlines invoking “Krakatau” without context can easily create unnecessary tsunami panic.

Jakarta was not the only airport affected

The scale of the ash cloud went beyond Soekarno-Hatta.

Reuters reported that six Indonesian airports eventually suspended operations because of volcanic ash, including the country's busiest international gateway.

Associated Press likewise reported widespread disruption across western Indonesia, with flight movements affected far beyond Jakarta.

That matters for travelers thinking they can simply reroute through another nearby Indonesian airport.

Alternative airports can themselves become constrained if the ash plume shifts.

Volcanic aviation disruption is highly dependent on wind direction, altitude and new eruptive activity—conditions that can change rapidly.

Schools and fishermen were affected too

This was not only an aviation story.

Reuters reported that schools in affected areas curtailed activities after students and residents suffered eye irritation from volcanic ash.

Fishing activities were also stopped in some areas near the volcano.

Indonesia’s disaster authorities advised residents exposed to ash to:

wear masks and eye protection;

reduce outdoor activities;

protect drinking-water sources;

and take extra care when driving because ash can reduce visibility.

Authorities were also preparing weather-modification efforts aimed at reducing ash fallout in populated areas, according to Reuters.

Airlines are offering rebooking and refunds

For Singapore passengers, SIA says travelers who booked directly with the airline can use its assistance process to rebook or request a refund.

Those who booked through travel agents or partner airlines should contact the seller that issued the ticket.

Scoot similarly said affected customers can rebook or request a full refund if they choose not to continue their trip.

Indonesia’s government has also said passengers whose flights were cancelled because of the airport closures are entitled to full refunds.

But refunding an air ticket may be the simplest part of the disruption.

Hotels, tours, airport transfers, work schedules and connecting flights can all carry different cancellation policies.

That is what passengers at both Changi and Soekarno-Hatta were discovering Sunday.

The real uncertainty begins after the ash clears

The dramatic images are of airport queues and erupting lava.

But for airlines, the real challenge is what happens next.

Hundreds of flights have already been displaced.

Aircraft are in the wrong cities.

Passengers have been moved onto later services.

Some crews may reach legal working-hour limits.

And Anak Krakatau remains at Alert Level III.

Even if Jakarta’s airport resumes operations, another significant ash plume could force fresh restrictions.

That means travelers between Singapore and Indonesia face two separate uncertainties:

when can the airport safely operate again?

And then:

how long will airlines need to untangle the backlog created while it was closed?

WWC ONE MEDIA M.J.E