Volcanic ash from Ili Lewotolok closes Wunopito Airport in Lewoleba

Lewoleba — Air traffic at Wunopito Airport in Lewoleba, East Nusa Tenggara, was temporarily halted after volcanic ash from Mount Ili Lewotolok entered the surrounding airspace on Tuesday, 8 September 2026, according to AirNav Indonesia and local media reports.

AirNav Indonesia, the state-owned air navigation service provider, said the closure was formalised through a Notice to Air Missions (NOTAM) that placed Wunopito (airport code WATW) under closed status due to volcanic ash from Ili Lewotolok.

In its written statement, AirNav said the NOTAM C1134/26, replacing NOTAM C1106/26, declared Wunopito closed from 07:01 on 8 September 2026 until an estimated 06:00 on 9 September 2026, with volcanic ash cited as the reason for the shutdown.

According to reports citing AirNav’s notice and the Ili Lewotolok monitoring post, the airport closure followed an eruption at 06:35 WITA on 8 September 2026.

Observers at the Ili Lewotolok volcano monitoring station reported an ash column reaching about 800 metres above the summit, or roughly 2,223 metres above sea level, with the plume drifting west.

AirNav’s Corporate Secretary Hermana Soegijantoro said the temporary closure was a safety measure in response to the spread of ash into airspace near Wunopito. The company noted that the NOTAM identified volcanic ash from Ili Lewotolok as the specific hazard affecting flight operations.

Why ash can stop flights

For aviation authorities, volcanic ash is treated as a critical safety factor even when lava or pyroclastic flows are confined to the volcano itself. The deciding issue is whether ash is present or forecast along an aircraft’s route or near an airport at levels that could affect safe operations.

AirNav said volcanic ash can interfere with flight safety when it is present along flight paths, and that the agency was monitoring the movement of the ash cloud and updating aeronautical information as conditions changed.

Technical thresholds such as ash concentration, distance from the plume and inspection requirements for aircraft were not detailed in the publicly available statement. However, standard international practice treats ash incursions into engine intakes, flight control systems and cockpit visibility as key risks in deciding whether to suspend operations.

For passengers, a NOTAM-issued closure does not necessarily indicate physical damage at the airport. It indicates that the aviation authority and operators have determined that available information does not support normal flight operations for the period specified in the notice.

The same principle applies to airspace assessments beyond the immediate airport perimeter. Authorities consider the reported eruption, the height and drift direction of the ash column, and the potential for ash to intersect flight paths when deciding whether to restrict or resume flights.

In the Wunopito case, AirNav said it was continuously monitoring dispersion patterns and coordinating with airlines and other aviation stakeholders before normal operations could resume.

Key figures from the reported closure on 8–9 September:

• Eruption time: 06:35 WITA, Tuesday, 8 September 2026
• Wunopito closure under NOTAM C1134/26: from 07:01 on 8 September
• Ash column: approximately 800 metres above the peak, about 2,223 metres above sea level
• Initial planned reopening: 06:00 on Wednesday, 9 September 2026

Extension of the closure

Subsequent updates from AirNav and Indonesian media show that the temporary closure at Wunopito was extended beyond 9 September as ash dispersion continued to affect local airspace.

A revised NOTAM, numbered C1145/26 and replacing C1134/26, kept Wunopito in closed status from 07:18 WITA on Wednesday, 9 September 2026, until an estimated 07:00 WITA on Thursday, 10 September 2026.

Later, AirNav announced that the closure of Wunopito would continue again from 07:23 WITA on Thursday, 17 September 2026, with operations expected to remain suspended until 07:00 WITA on Friday, 18 September 2026, still due to volcanic ash from Ili Lewotolok.

Through these notices, AirNav emphasised that aviation safety remained the priority and that operations would resume only after coordination with airlines and other relevant stakeholders, and once ash conditions no longer posed an unacceptable risk to flight operations.

Sources

• VIVA - Abu Vulkanik Erupsi Gunung Lewotolok Menyebar, Bandara Wunopito NTT Ditutup Sementara
• CNBC Indonesia - Bandara Wunopito Ditutup Efek Abu Vulkanik Gunung Lewotolok
• Media Indonesia - Gunung Lewotolok Erupsi Lagi, Kolom Abu Terpantau Setinggi 800 Meter
• Katadata - Bandara Wunopito NTT Masih Ditutup Imbas Abu Vulkanik Gunung Lewotolok
• JPNN - UPDATE NOTAM: Bandara Wunopito NTT Ditutup
• AirNav Indonesia