Newsroom

KUALANAMU, 31 August 2026 — The eruption of Mount Sinabung in Karo Regency, North Sumatra, may affect flight operations to and from Kualanamu International Airport in Deli Serdang, North Sumatra (KNO), if volcanic ash is carried by the wind and spreads into flight paths or the area surrounding the airport.

Volcanic ash differs from ordinary weather conditions. Its dispersion largely depends on wind direction and speed, the intensity of the eruption, and atmospheric conditions, meaning the situation can change relatively quickly. Therefore, flights previously scheduled to operate may be adjusted if developments in the spread of volcanic ash indicate a potential risk to aviation safety.

Under these circumstances, Lion Group flights to and from Kualanamu may experience departure or arrival delays, flight rerouting, or cancellations. Operational decisions are made based on current conditions and coordination with relevant parties, including the airport operator, aviation authorities, and agencies monitoring volcanic activity and ash dispersion.

For customers, sudden delays or cancellations are part of the operational adjustments that may be necessary when conditions on the ground change. Departure and arrival times cannot be determined solely by conditions at the time an aircraft is scheduled to depart, as conditions along the flight path and at the destination must also be taken into consideration.

Volcanic ash has characteristics that may pose a hazard to aviation. If it enters a flight path, volcanic ash can reduce visibility and affect the performance of aircraft engines and components. These conditions must also be considered by flight crews when operating a flight. Aircraft will therefore not be operated through areas where volcanic ash is assessed as posing a risk to aviation safety.

Lion Group continues to coordinate with the relevant parties and monitor developments in Mount Sinabung’s activity, volcanic ash dispersion information, weather conditions, and airport operations. Flight adjustments are made dynamically in accordance with prevailing conditions and the latest available aviation safety information.

Conditions caused by a volcanic eruption constitute force majeure—circumstances beyond Lion Group’s control and capabilities arising from natural events or extraordinary conditions that may affect flight operations. In such situations, aviation safety remains the primary consideration in every operational decision.

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