A History of Ash and Aviation

How the CAA has responded to ash events in UK airspace

Volcanoes erupt frequently, but normally only affect areas where air traffic is light and airspace is uncongested.  The resulting ash clouds are tracked by nine global Volcanic Ash Advisory Centres which provide information to allow flights to (where possible) reroute their flight paths around any area of contamination.

When the Eyjafjallajokul volcano erupted the guidance used worldwide from the International Civil Aviation Organisation, was to avoid any amount of ash. The guidance actually stated: ‘“in the case of volcanic ash, regardless of ash concentration — avoid, avoid, avoid.”.’

The eruption of Eyjafjallajokul in Spring 2010 was very different to previous incidents in that it affected some of the most congested airspace in the world and, as the ash covered much of Europe, flying round it was not an option. There was no precedent for this type of situation and because of the ICAO guidance UK air traffic control body NATS announced that it would not provide clearance for flights in contaminated airspace. 

The UK was not alone in the action it took.  Other European countries followed suit as ash clouds drifted into their airspace.

UK work with International and European regulators

The disruption to European airspace meant it was imperative that action was taken at a national, European and international level. 
International and European regulators, manufacturers and aviation experts, had to co-ordinate their expertise and agree a new zoning system for airspace affected by volcanic ash. 

The CAA took the lead in getting this work underway and after five days of intensive conference calls with hundreds of experts, the necessary data was amassed for the basis of the new guidelines.

The CAA’s work on volcanic ash did not stop once the skies re-opened. The CAA has continued to put considerable effort and resources into improving the way aviation deals with volcanic ash. After Eyjafjallajokul the CAA led Europe in developing and implementing the regulatory regime that is now in place and was used during the 2011 Grimsvotn eruption.

Timelines of ash events that have affected UK airspace:

How we are planning for future ash events.