Why is volcanic ash a safety concern for flights?, Pg10

Key Highlights:

• The DGCA ordered airlines to prepare for volcanic ash from the Hayli Gubbi volcano in Ethiopia, which erupted on November 23.
• The volcanic ash cloud reached India's western border on November 24, moving at 100-120 km/hour at an altitude of 15,000 to 25,000 feet.
• The ash cloud contained volcanic ash, sulphur dioxide, and tiny particles of glass and rock, affecting air quality over Rajasthan, Gujarat, Delhi-NCR, Punjab, and Uttar Pradesh.
• Air India and Akasa cancelled several flights due to the volcanic ash, including those originating from Dubai, Doha, Dammam, Jeddah, Kuwait, and Abu Dhabi.

Detailed Insights:

• The Hayli Gubbi volcano erupted for the first time in nearly 12,000 years, sending ash plumes up to 14 km into the sky, drifting towards Yemen, Oman, and Iran.
• Volcanic ash can cause jet engines to lose power or shut down because the silicate components melt and re-solidify, creating glassy deposits that block cooling holes.
• The DGCA advised airlines to avoid affected altitudes and regions, report any suspected ash impact, and ordered airports to inspect runways, potentially suspending flight operations.
• In 1982, a British Airways Boeing 747 experienced all four engines failing due to volcanic ash from Mount Galunggung, and in 1989, a KLM Boeing 747-400 had a similar incident with ash from Mount Redoubt.

Scientific/Technical Concepts Involved:

• Volcanic Ash: Fine particles of rock, minerals, and glass ejected from a volcano during an eruption.
• Jet Engine: A type of engine that produces thrust by expelling hot exhaust gases.
• Silicates: Minerals containing silicon and oxygen, common in volcanic ash, which can melt and resolidify at high temperatures.