Impact of volcanic ash on air traffic

Over the main period of the crisis (15th -22nd April), airspace closures in Europe resulting from the eruption of the Eyjafjallajökull volcano led to the disruption of over 100,000 flights and 10 million passenger journeys. The economic impact and the operational decisions have been addressed elsewhere (see Links section). To complement these studies, Eurocontrol’s statistics service, STATFOR, has published an assessment of the impact in terms of traffic. It considers the impact in terms of numbers of flights, with the principal aim of helping those who will analyse traffic statistics and their trends in the coming months and years. The report concerns the period from 15th -22nd April and includes estimates due to eruptions early in May.

Although the main period of the crisis was from 15th - 22nd April, the effects started earlier and continued later, especially in Scandinavia and Iceland. 104,000 flights were cancelled during the 8-day crisis. That is 48% of expected traffic over 8 days, peaking at 80% on 18th April. That implies approximately 10 million passengers were unable to board their flights. A further 7,000 flights were cancelled due to the ash in May.

Figure 1: Traffic in Europe before and during the crisis
Amongst the flights which actually took place during the crisis were more than 5,000 additional flights put on by scheduled and charter carriers. These additional flights were for one or more of three reasons: to reposition aircraft; to reposition crews; and to accelerate the repatriation of stranded passengers. For simplicity, the estimates presented elsewhere in this report are not adjusted to remove the effects of these flights.

Aside from Iceland, Finland, Ireland and the UK saw a 90% reduction in traffic in April over 5 consecutive days. Santa Maria (airspace of the Azores) was the only region with a net increase in flights. In April, Icelandic traffic was affected for 13 rather than the 8 days seen elsewhere. The impact over the whole month was not quite as high as worst-affected Finland, principally because Iceland was able to maintain some flights to North America.

Low-cost traffic was the hardest hit, losing 61% of flights over the 8-day crisis, compared to 48% for all traffic. Higher exposure and a less flexible business model are likely causes of this. Business aviation was least affected, with traffic down 34%.

The most affected airports correspond to the most affected states: Helsinki, Dublin, Manchester and Edinburgh all had fewer than 25% of the expected number of flights over the 8-day period.

Air traffic delays in April were up compared to April 2009 (which was a historic low), though better than recent months. Unsurprisingly, there was a large increase in delays attributed to ‘other’ (ie volcanic activity). However, May saw a much bigger impact in terms of delays, with 43% of the flights delayed in departure (10 percentage point increase compared to the same month last year).
The calculations in terms of traffic disruptions performed in this report have been used to adjust the historical data (April) for the purpose of the Short-Term Forecasts (traffic and service units) produced by STATFOR in May 2010. For short-term forecasting, this raises the challenge of considering how to adjust the forecast for future months to allow for the uncertainty of further eruptions.

Following the volcanic ash cloud crisis, the European Commission, EUROCONTROL and the European Aviation Safety Agency (EASA) created the European Aviation Crisis Coordination Cell (EACCC) on 21st May 2010, enabling Member States to coordinate their responses in the event of any future pan-European crisis severely affecting aviation.

Full report

  HTML Ash-cloud of April and May 2010: Impact on Air Traffic



  HTML STATFOR Short-Term Forecasts
  HTML STATFOR Interactive Dashboard (SID) portal
  HTML Special report on volcanic ash cloud
  HTML CFMU Network Operations Portal (NOP)
  Acrobat European Aviation Crisis Coordination Cell EACCC
  Acrobat First Look at Delays - April 2010, Central Office for Delay Analysis (CODA)

Other links

  Acrobat Oxford Economics report prepared for Airbus: The Economic Impacts of Air Travel Restrictions Due to Volcanic Ash (May 2010)
  Acrobat IATA Economic Briefing: The impact of Eyjafjallajokull’s volcanic ash plume (May 2010)


Claire Leleu
David Marsh
  Last validation: 01/07/2010