Flight Operations Undisturbed by Semeru Eruption

JAKARTA, KOMPAS - Flight activities in several cities such as Surabaya, Malang, Banyuwangi, and Yogyakarta have not been affected by the eruption of Mount Semeru in East Java. So far, flights are operating normally and there have been no airport closures.

AirNav Indonesia Executive Vice President Corporate Secretary Hermana Soegijantoro said that so far no airports have been closed and no flights have been canceled. "As of the time of this publication, the situation has not reached a point where airspace needs to be closed due to the threat of volcanic ash clouds," Hermana said in a press release received by Kompas.id on Thursday (November 20, 2025).

Nevertheless, Hermana emphasized that Airnav Indonesia continues to monitor intensively the flight routes and airports that may be affected. Airnav will also consistently provide updates on the latest developments. Flight route adjustments will be made if necessary, in accordance with the latest information from the volcanic information center and weather satellites.

In the latest report, the status of Mount Semeru has been designated as "Red Code," indicating that the eruption activity is quite significant and has the potential to disrupt flight routes.

Volcanic ash has been observed at two different altitudes. At the lower level, the ash distribution is at an elevation of approximately 4,500 meters above sea level (asl). The ash is moving southeast at a wind speed of about 5 knots.

The ash plume is spreading at a high altitude of 13,500 meters above sea level. Winds are blowing southwest at 15 knots.

In the latest observation prior to the aviation safety NOTAM, high-altitude ash was difficult to detect due to cloud cover; however, movement models indicate that the ash will weaken in the coming hours. Meanwhile, low-altitude ash remains clearly monitored and continues to move towards the southeast.

"However, the current trend shows that the distribution of volcanic ash is increasingly moving away from the surrounding airports and flight routes that may be affected," said Hermana.

The results of the paper tests conducted by PT Angkasa Pura Indonesia and the airport authority offices at nearby airports were all negative.

Meanwhile, the Legal and Public Relations Manager of Daop IX Jember, Cahyo Widiantoro, stated that train travel remains safe following the Semeru eruption.

After the eruption of Semeru, KAI Daop 9 inspected the railway line between Jatiroto and Ranuyoso, which is closest to Mount Semeru. The team examined the railway tracks, bridges, stations, and level crossings to ensure the operational safety of the trains.

As a result, all infrastructure and railway lines in that corridor are in a safe condition. No volcanic materials such as ash or sand that could disrupt the tracks or signaling were found. All train services are operating normally according to schedule.

KAI Daop 9 has also increased patrols along the tracks and has prepared track cleaning equipment to anticipate any potential ash rain in the operational area.

As is known, Mount Semeru in East Java erupted on Wednesday (19/11/2025) at 16:00 WIB. The status of Mount Semeru was raised from Level II (Alert) to Level IV (Caution) on Wednesday at 17:00 WIB, just one hour after the eruption. Hot clouds have been observed striking Gladak Perak, the main bridge connecting Malang and Lumajang regencies.