Entries for the Tag:London
Volcanic Ash is Dangerous for Aircraft
Thousands of airline flights cancelled due to dangerous ash plume
Earlier this week a volcano under an Icelandic Glacier erupted and spewed thousands of tons of ash into the atmosphere causing the cancellations of thousands of flights across the globe. Currently all airspace in Great Britain Belgium, Denmark, Finland, Lithuania, Estonia, and the Netherlands, is completely closed to all aircraft while airspace was partially closed in France, Germany, Poland, Sweden, Norway, and Ireland. US airlines are cancelling flights to/from Europe stranding thousands of passengers. It is simply too dangerous to fly.
Volcanic ash clouds are a serious hazard to aviation, reducing visibility, damaging flight controls and ultimately causing jet engines to fail. Encounters between aircraft and volcanic ash can happen because ash clouds are difficult to distinguish from ordinary clouds, both visually and on radar, according to the U.S. Geological Survey. Ash clouds can also drift great distances from their source. The eruption in Iceland sent a huge plume of ash moving across the Atlantic, disrupting air traffic across Western Europe.
According to Boeing, flying through an ash cloud should be avoided by all means. The aircraft manufacturer says experience has shown costly damage can occur to aircraft surfaces, windshields and power plants, while ventilation, hydraulic, electronic and air data systems can also be contaminated. Critically, it says the ingestion of volcanic ash by engines may cause serious deterioration of engine performance due to erosion of moving parts and partial or complete blocking of fuel nozzles. One former pilot said, “it’s like throwing a bucket of beach sand into the engine”. But it is actually much worse, while the sand would pit and gouge the critically balanced surfaces of a high performance jet engine, eventually the sand would work its way through the system. But the ash is much more insidious. Volcanic ash contains particles, whose melting point is below that of an engine’s internal temperature. During flight these particles will immediately melt if they go through an engine. Going through the turbine, the melted materials rapidly cool down, stick on the turbine vanes, and disturb the flow of high-pressure combustion gases. In the worst case this disorder of the flow may completely stall the engine, causing a complete shutdown of not only the propulsion systems, but electrical, environmental, and oxygen/pressurization systems.
