An Icelandic volcano is in the news again. In 2010, it was Eyjafjallajökull, which caused the cancelation of over 100,000 flights and cost airlines $1.7 billion. This time, it's Bardarbunga. An eruption of Bardarbunga could potentially disrupt flights once again, as well as melt the glaciers under which it resides.
What's the big deal if a plane flies through volcanic ash? It's more than just dust to a jet engine, it's actually tiny shards of glass. Obviously, ingesting glass is not good for a jet engine. Volcanic ash melts into glass at 2,000 degrees Fahrenheit. Jet engines run roughly 500 degrees hotter. The melted glass then adheres to the fan blades and fuel nozzles which can cause jet engines to shut down. It has happened at least twice before.
British Airways 747-200 by Dean Morley (CC Commercial License)
In 1982, British Airways flight 9 flew through a cloud of ash that had been spewed into the atmosphere by Mount Galunggung, 110 miles southeast of Jakarta, Indonesia. All four engines on the Boeing 747-200 failed. Neither the crew or air traffic control could identify what caused the failure, but the plane was able to glide out of the ash cloud, where the engines were restarted. The flight diverted to Jakarta and landed safely.
Then in 1989, another 747 suffered the same problem. KLM flight 867, another Boeing 747, flew through the ash of Mount Redoubt, which had erupted in southern Alaska the day before. Once again, all four engines failed, but the pilots were able to restart the engines and landed the plane in Anchorage after losing 14,000 feet of altitude.
Flying through an ash cloud should be avoided by all means due to the extreme hazard for the aircraft. Experience has shown that damage can occur to aircraft surfaces, windshields and powerplants. Aircraft ventilation, hydraulic, electronic and air data systems, can also be contaminated.
In their volcanic ash awareness guide, Airbus also notes that ash incidents affecting aircraft have occurred as far as 2,400 nautical miles from the eruption. Boeing says that over 90 commercial jets have been damaged by ash in the past 30 years, including the 1980 eruption of Mt. Saint Helens, and the 1991 Mt. Pinatubo eruption.
Since Sunday, thousands of small earthquakes have occurred in the Bardarbunga area, sparking concerns and predictions of an imminent eruption. Volcanologists are not predicting as big of an impact on flights from Bardarbunga as the 2010 eruption of Eyjafjallajökull, but they say it will depend on the magnitude of the eruption, as well as weather conditions such as wind direction.
Top image: 2010 Eyjafjallajökull eruprtion. Getty images.