JAKARTA, thekabarnews.com—Four Indonesian airports resumed operations early Tuesday, September 8. This happened after repeated ground tests found no volcanic ash from Anak Krakatau. However, aviation authorities continued to restrict flights from entering affected airspace.

The Meteorology, Climatology and Geophysics Agency (BMKG) reported the negative results during a disaster-response meeting. President Prabowo Subianto led this meeting at the Merdeka Palace on Monday, September 7.

BMKG head Teuku Faisal Fathani identified the four facilities as Soekarno-Hatta International Airport in Banten. He also listed Halim Perdanakusuma Airport in Jakarta, Husein Sastranegara Airport in Bandung, and Budiarto Airport in Curug.

“Paper-test observations at four airports returned negative results,” Faisal said during the meeting.

A paper test detects ash particles settling at an airport. Authorities use the result alongside satellite images, atmospheric observations and aviation warnings.

A negative test means the method did not detect ash at the testing location and time. It does not necessarily rule out volcanic ash elsewhere in the surrounding airspace.

Faisal said Soekarno-Hatta recorded the most consistent improvement.

“At Soekarno-Hatta, four consecutive paper tests returned negative results,” he said.

BMKG subsequently communicated its observations to the Transportation Ministry and the Darwin Volcanic Ash Advisory Center (VAAC).

The findings did not trigger an immediate reopening on Monday. Transportation Minister Dudy Purwagandhi said authorities adopted a cautious approach. This caution was because changes in wind direction could carry ash back toward airports and flight routes.

The Transportation Ministry later reopened Soekarno-Hatta, Halim Perdanakusuma and Husein Sastranegara at 12:01 a.m. on Tuesday. Budiarto and Pondok Cabe airports reopened at 2:25 a.m., according to the ministry’s official.

Atung Bungsu Airport in South Sumatra had already resumed operations at 9 a.m. on Monday. When the ministry issued its latest statement, Radin Inten II and Muhammad Taufiq Kiemas airports in Lampung were still under review.

Airport authorities required airlines to inspect aircraft before operating them again. Pilots and flight crews also received information about restricted polygons. These are designated sections of airspace that aircraft must avoid because volcanic ash may still be present.

BMKG had issued 39 Significant Meteorological Information (SIGMET) notices between Anak Krakatau’s initial eruption on September 4 and Monday morning.

A SIGMET warns aircraft operators about hazardous atmospheric conditions along flight routes. Satellite monitoring on Monday still detected ash moving west at up to 15,000 feet, according to BMKG.

The disruption affected 2,961 domestic and international flights through Monday afternoon, including cancellations, delays and diversions. About 341,000 passengers were affected, according to the Transportation Ministry.

The reopening restores major flight connections through Jakarta and Bandung. Passengers should continue checking their flight status because eruptions and ash-dispersion patterns can change rapidly.