MANILA, Philippines?Mount Pinatubo disrupted civil aviation when it erupted in June 1991, spewing huge clouds of volcanic ash and acid gases about 30 kilometers into the air.
The ash clouds, carried by winds, circled the globe and affected some of the world?s busiest air traffic corridors.
Within days, at least 16 commercial jet planes were damaged by encounters with ash clouds from Pinatubo, according to the US Geological Survey.
The encounters caused loss of power to one engine on each of two different aircraft. A total of 10 engines were damaged and replaced, including all four engines of a single jumbo jet.
Longer term damage to aircraft and engines was reported, including accumulation of sulfate deposits in engines.
The ash fall also damaged aircraft on the ground and affected facilities at Cubi Point, Clark and Basa airports.
According to one report, the Pinatubo eruption was the largest disturbance of the stratosphere since the eruption of Krakatau in 1883. As a result of the Pinatubo blast, the temperature of the entire planet was said to have cooled by 0.4 to 0.5?C.
The eruption is believed to have influenced such events as the 1993 floods along the Mississippi River and the drought in the Sahel region of Africa.
In a report, the National Aeronautics and Space Administration (Nasa) said that volcanic eruptions of Pinatubo?s magnitude could affect global climate, reducing the amount of solar radiation reaching the Earth?s surface, lowering temperatures in the troposphere, and changing atmospheric circulation patterns.
Source: ?The 1991 Pinatubo eruptions and their effects on aircraft operations,? 1999 study by United States Geological Survey (USGS), United States of America; ?The Volcanic Mount Pinatubo Eruption of 1991 that Cooled the Planet? in http://geography.about.com/