Relevance: GS-1 (Geography – Natural Hazards), GS-3 (Environment, Disaster Management)
Source: Indian Express, Directorate General of Civil Aviation

The Hayli Gubbi volcano in Ethiopia erupted after nearly 12,000 years, sending volcanic ash across the Red Sea region and even into western and northern India, prompting an aviation safety advisory.

Why Volcanoes Are Dangerous for Aviation

Volcanic ash is not smoke—it consists of microscopic, abrasive rock and glass particles that:

• Melt inside aircraft engines, forming glass-like coatings on turbine blades → engine failure or shutdown.
  
• Clog sensors and impair cockpit visibility.
  
• Damage windshields, airframes, and pneumatic systems.
  
• Enter aircraft ventilation, reducing cabin air quality.
  
• Remain suspended for days, travelling thousands of kilometres through upper-air currents.

Past incidents:

• 1989: A KLM Boeing 747 flying near Mt. Redoubt (Alaska) suffered engine failure in all four engines after ash ingestion.
  
• 1992: British Airways flight over Indonesia lost all engines after flying into an ash plume.
  

Impact of Hayli Gubbi Ash on India

• Ash clouds travelled via upper-level westerlies, reaching Gujarat, Rajasthan, Delhi, Uttar Pradesh and further drifting northeast.
  
• Some flights were cancelled or diverted; pilots reported visibility issues and engine performance warnings.
  
• The Directorate General of Civil Aviation advised airlines to:
  
  • Avoid ash-affected routes and altitudes.
    
  • Monitor any engine anomaly or cabin smoke/odour.
    
  • Follow International Civil Aviation Organization volcanic ash protocols.
    

Q. Volcanic ash is hazardous for aircraft primarily because it:
A) Contains toxic gases harmful to passengers
B) Melts inside engines and coats turbine blades
C) Causes electromagnetic interference
D) Increases humidity inside aircraft cabins