Reply to thread

Message: <blockquote data-quote="පංචායුධ" data-source="post: 7299645" data-attributes="member: 277885">How Volcanic Ash Can Kill An Airplane<img src="http://cache.gawkerassets.com/assets/images/12/2010/04/500x_pinatubo-volcano-plane.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />As volcanic ash spreads from an eruption <a href="http://gizmodo.com/5517678/icelands-volcanic-ash-causes-hundreds-of-european-flight-cancellations" target="_blank">under  a glacier in the Eyjafjallajokull region of Iceland</a>, the British  have taken <a href="http://www.nytimes.com/2010/04/16/world/europe/16ash.html?src=me" target="_blank">the  drastic step</a> of locking down the country's airspace. Here's why. The world's bustling air traffic corridors pass over hundreds of  volcanoes just like the one in Iceland — all of which are capable of  sudden, explosive eruptions of fire and ash. In the United States alone,  aircraft carry many thousands of passengers and millions of dollars of  cargo over volcanoes each day. As we see today, volcanic ash can be a  serious hazard to aviation even thousands of miles from an eruption.  Airborne ash can diminish visibility, damage flight control systems, and  most importantly, cause jet <a href="http://jalopnik.com/tag/engines/" target="_blank">engines</a> to fail.<img src="http://cache.gawkerassets.com/assets/images/12/2010/04/iceland-volcano-flooding-new-plumes-steam_18902_600x450.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />In fact, according to Boeing public relations officials, in <a href="http://www.boeing.com/commercial/aeromagazine/aero_09/volcanic_story.html" target="_blank">the  past 30 years</a>, more than 90 jet-powered commercial airplanes have  encountered clouds of volcanic ash and suffered damage as a result. Here's an example of one such case. The Story of KLM Flight 867 On December 15, 1989, clouds of ash from an eruption at Mt. Redoubt  Volcano in Alaska nearly caused a Boeing 747 jetliner (<a href="http://en.wikipedia.org/wiki/KLM_Flight_867" target="_blank">KLM Flight 867</a>)  carrying 231 passengers to <a href="http://pubs.usgs.gov/fs/fs030-97/" target="_blank">crash  land</a> after losing power to all four <a href="http://jalopnik.com/tag/engines/" target="_blank">engines</a>. As the crew of KLM Flight 867 struggled to restart the plane's  engines, "smoke" and a strong odor of sulfur filled the cockpit and  cabin. For five long minutes the powerless 747 jetliner, bound for  Anchorage, Alaska, with 231 terrified passengers aboard, fell in silence  toward the rugged, snow-covered Talkeetna Mountains (7,000 to 11,000  feet high). All four engines had flamed out when the aircraft  inadvertently entered a cloud of ash blown from erupting Redoubt  Volcano, 150 miles away. The volcano had begun erupting 10 hours earlier  on that morning of December 15, 1989. Only after the crippled jet had  dropped from an altitude of 27,900 feet to 13,300 feet (a fall of more  than 2 miles) was the crew able to restart all engines and land the  plane safely at Anchorage. The plane required $80 million in repairs,  including the replacement of all four damaged engines.How did it happen? <img src="http://cache.gawkerassets.com/assets/images/12/2010/04/340x_custom_1271336293849_boeing_volcanic_ash_engine.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />It's a process that's sort of like Mother Nature's version of <a href="http://jalopnik.com/5327580/video-how-to-disable-a-cash-for-clunkers-car" target="_blank">a  "Cash for Clunkers" engine getting killed</a>. Volcanic ash normally  contains glassy materials, such as silicates, whose melting points are  600 degrees Celsius to 800 degrees Celsius. Since internal temperature  of in-flight jet engine exceed 1000 degrees Celsius, glassy particles in  volcanic ash inhaled by the engines instantly melt. In the course of  exhaust, the glassy materials are rapidly cooled down in the turbine  chamber, stick on the turbine vanes, and disturb the flow of  high-pressure combustion gases. This disorder of the flow may stop the  entire engine in serious cases — such as KLM Flight 867. Such dangerous and costly encounters between aircraft and volcanic  ash can happen because ash clouds are difficult to distinguish from  ordinary clouds, both visually and on radar. Also, ash clouds can drift  great distances from their source. For example, in less than 3 days, the  ash cloud from the June 15, 1991, eruption of Mount Pinatubo in the  Philippines traveled more than 5,000 miles to the east coast of Africa.  This ash cloud damaged more than 20 aircraft — including the DC-10 shown  above — most of which were flying more than 600 miles from the volcano. So today's decision by British aviation officials to clear UK  airspace until at least 1:00 am EST on Friday, while difficult, makes a  heck of a lot of sense.                                            source:  <a href="http://jalopnik.com/5517775/how-volcanic-ash-can-kill-an-airplane" target="_blank">http://jalopnik.com/5517775/how-volcanic-ash-can-kill-an-airplane</a>                                  <a href="http://ad.doubleclick.net/jump/gm.jalopnik/inside;ptile=3;sz=728x90;ord=70691287?" target="_blank"><img src="http://ad.doubleclick.net/ad/gm.jalopnik/inside;ptile=3;sz=728x90;ord=70691287?" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a><a href="http://artists.gawker.com/5062963/shai-dahan" target="_blank"><img src="http://s0.2mdn.net/1289772/Shai_Dahan1_800x250.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>                  <img src="http://track.gawker.com/stats/count/post?i=5517775&s=4264fae2&u=1" alt="" class="fr-fic fr-dii fr-draggable " style="" /></blockquote>

Verification: Nawa warak dahaya keeyada? (Namaya wadi kireema dahaya)

Top Bottom