Volcanic Ash consists of small (up to 2 millimetres in diameter) pieces of pulverized rock and glass that are thrown into the atmosphere during an eruption. It can cause breathing problems and may lead to equipment malfunctions, especially if ingested by aircraft engines.
A strong misconception amongst air navigation service providers (ANSPs) is that volcanic ash does not affect them when there are no volcanoes in or near to their territory. However volcanic ash travels for thousands of miles and the ash cloud itself can be in excess of 2000 miles long. Examples of volcanic ash affecting aircraft include a DC9 on descent into El Paso, Texas in 1989, damaged by volcanic ash from Alaska. Within Europe, volcanic activities in Iceland, Italy, the Canary Islands and the Azores all pose a potential threat depending on weather patterns.
The safety implications for aircraft routing through volcanic ash clouds are well known and obvious. ANSPs are encouraged, therefore, to consider the information provided in the reference material below, in particular with regard to their coordination with the Volcanic Ash Advisory Centres/Meteorological Watch Offices, airlines and Central Flow Management Unit (CFMU). Moreover, ANSPs should take an active part in the volcanic ash exercises organised in their areas of responsibility to ensure their readiness in case of actual volcanic ash activity.