CAAP warns pilots: Kanlaon Volcano ash cloud prompts 13,000-foot flight restriction

The Civil Aviation Authority of the Philippines (CAAP) has issued a critical Notices to Airmen (NOTAM). This advisory restricts flights near the Kanlaon Volcano ash emission site. The action follows a weak ash event confirmed by the Philippine Institute of Volcanology and Seismology (Phivolcs).

Phivolcs reported the ash emission on Tuesday, January 6, 2026. Grayish plumes were observed rising from the volcano's summit crater early that morning. The plumes reached a height of 350 meters before drifting southwest.

Aviation Safety Warning and NOTAM Details

The CAAP's NOTAM is a direct response to the volcanic ash cloud hazard. It establishes a vertical flight limit up to 13,000 feet above the volcano's surface. This restriction is effective from January 6 to January 7, 2026. The agency strongly advised all aircraft operators warning to avoid the area. This is a standard procedure to ensure commercial aviation safety near active volcanoes.

Phivolcs also reiterated its warning to aircraft operators against flying close. The risk comes from both ash and steam emissions. Volcanic ash poses a severe danger to jet engines and aircraft systems. International standards for aviation safety around volcanoes are set by bodies like the ICAO.

Volcanic Activity Monitoring

Despite the brief emission, Alert Level 2 (Increased Unrest) remains in effect. Kanlaon Volcano straddles Negros Occidental and Negros Oriental provinces. This Phivolcs advisory signifies moderate unrest and the possibility of further activity.

Monitoring data from Phivolcs supports the continued high alert status. The 24-hour observation period recorded one volcanic earthquake. This seismic activity suggests ongoing unrest beneath the volcano's surface. Sulfur dioxide (SO₂) emissions were measured at 1,484 tonnes per day on January 5. This high reading suggests continued degassing from the magma. Ground deformation data also shows the volcanic edifice remains inflated. This is a key sign that magmatic or hydrothermal processes are still active.

The Risk of Volcanic Ash to Aircraft

Volcanic ash is one of the most significant hazards in the air. Ash particles are hard, abrasive, and primarily composed of silicates. When ingested by jet engines, the silicates melt in the hot section. This molten material then fuses onto turbine blades and guide vanes.

• The resulting ceramic mass can cause engine surge and total engine failure.
• Ash abrasion can scratch cockpit windows, impairing pilot visibility.
• It can also clog the pitot-static system, which is vital for airspeed and altitude readings.

Aircraft manufacturers, such as Airbus, design engines to withstand many elements. However, volcanic ash at high concentrations presents an extreme threat. Pilots are trained to reduce thrust quickly to idle to prevent silicate melting. This is a last-resort maneuver.

Phivolcs strictly prohibits entry into the 4-kilometer Permanent Danger Zone (PDZ). Local authorities are urged to remain vigilant for hazards. These include sudden steam-driven or phreatic eruptions and ashfall. For more information on this and other developments, visit our commercial aviation news section at flying.flights.