The European volcanic ash crisis: Between international and European law

DISCLAIMER: All opinions in this column reflect the views of the author(s), not of EURACTIV Media network.

During the European volcanic ash crisis, actions taken by national authorities led to unprecedented disruptions and severe economic effects for the airline industry. The time seems ripe to unite the EU's airspace, writes Alberto Alemanno, associate professor of EU law at HEC Paris and adjunct professor at Georgetown Law School, in a July commentary for the American Society of International Law (ASIL).

The following commentary was authored by Alberto Alemanno for ASIL.

''Following the eruption of the Icelandic volcano Eyjafjallajökull on 14 April 2010, a cloud of ash, helped by winds, quickly spread across Europe. Since volcanic ash is a recognised threat to aircraft, most European civil aviation authorities, following well established and widely published international safety protocols issued by the International Civil Aviation Organisation (ICAO), closed their airspace.

The impact of the six-day closure was enormous: more than 100,000 flights were cancelled and about ten million passengers were unable to travel. In many cases, passengers were stranded in another country without any immediate possibility of going home. This situation not only placed the existing international framework for operational response to volcanic ash under a stress test, it also highlighted the limited level of integration achieved by the European Union (EU) in the civil aviation sector.

The flying bans were instituted because of fears that the volcanic ash – a mixture of glass, sand, and rock particles – could seriously damage aircraft engines. The national measures were based on scientific advice provided by the Volcanic Ash Advisory Centre (VAAC) and were implemented by the European Organisation for the Safety of Air Navigation (EuroControl).

Yet even before the bans were lifted, recriminations among all those involved began. National authorities came under pressure from European airlines, several of whom claimed that successful test flights were conducted in the supposed danger zone.

After three days of flying bans, all major airlines vocally claimed that authorities had been overly cautious in using a precautionary approach. In addition, critics disputed the model (Numerical Atmospheric-dispersion Modelling Environment, or NAME) used by the VAAC, which was originally developed to track radioactive fallout from the Chernobyl nuclear disaster in 1986. They dismissed its model-based estimates of the extent of the ash cloud as 'theoretical'.

National authorities defended their 'zero risk' regulatory response, claiming that it was consistent with the guidelines developed by ICAO in the 2007 Manual on Volcanic Ash, as well as with the Volcanic Ash Contingency Plan – EUR Region. In turn, scientists strenuously defended the predictions made by the NAME atmospheric dispersion model underpinning the ICAO guidelines.

The European Regulatory Response

Meanwhile, the cloud was not moving. As Europe was facing another week of disruption, the European Commission – acting outside of its competence – took the initiative over the weekend of 17-18 April, with the Spanish Presidency and EuroControl, to propose a coordinated European approach.

As the situation evolved, the NAME model and the national risk management procedures were tested. EU member states, national air safety authorities, national air traffic controllers, and EuroControl realised that a more differentiated assessment of risk from the ash cloud was needed. But no member state could act independently by departing from the ICAO guidelines and taking the first step to introduce change.

The guidelines are unequivocal regarding the danger of volcanic ash for aircraft engines:

Unfortunately, at present there are no agreed values of ash concentration which constitute a hazard to jet aircraft engines […] but it is worth noting at this stage that the exposure time of the engines to the ash and the thrust settings at the time of the encounter both have a direct bearing on the threshold value of ash concentration that constitutes a hazard.

In view of this, the recommended procedure in the case of volcanic ash is exactly the same as with low-level wind shear, regardless of ash concentration — AVOID AVOID AVOID.

Yet, five days after the enforcement of the national flying bans, on 19 April, EuroControl member states unanimously agreed to move to 'a co-ordinated European approach in response to the crisis'. As a result, new procedures were defined, which led to a partial reopening of European air space and hence reduced the human and economic impact on passengers, airlines and cargo.

The new measures came into force on 20 April and established three types of zone (depending on the degree of contamination). The first zone was located in the central nucleus of the emissions, where a full restriction of operations was maintained; the second consisted of an intermediary zone, where member states could allow flights 'in a coordinated manner [with other members]' but with additional restrictions and safety controls; and the third zone, not affected by the ash, had no restrictions.

These procedures, based on a more differentiated risk assessment and paving the way for more coordinated decision-making among states, enabled 'a progressive and coordinated opening of European airspace'. By 22 April, eight days after the eruption had begun, regular flight schedules resumed.

The legal implications of the crisis

The situation created by the protracted closure of the European airspace has been so extraordinary that the regulatory action leading to the disruption continues to be at the centre of a growing controversy. Beyond the personal dramatic situations experienced by millions of stranded passengers and difficult implementation of the Passengers' Rights Regulation, the air industry has incurred significant costs and suffered reduced revenues.

To address these concerns, the Commission has concluded that member states should rapidly implement measures in favour of the air industry that would repair the damage caused by the natural disaster.

Moreover, the disruption may also have some unforeseen financial consequences for the EU's Emissions Trading Scheme (ETS). Indeed, since 2010 is the monitoring year for the establishment of the number of Aviation Allowances (AAs) allocated for free to airlines, the reduced activity in April could affect the distribution of those allowances between aircraft operators.

The regulatory consequences stemming from the crisis were not limited to the aviation sector. Thus, for instance, since 14 April 2010, the European Commission has raised questions about public health resulting from the ash cloud that covered large parts of the European Union.

As a result, the Commission asked the European Centre for Disease Prevention and Control (ECDC) to assess the potential impact of the ash cloud on public health, and the European Food Safety Authority (EFSA) to obtain urgent advice on the possible risks for public and animal health of the contamination of the feed and food chain.

The EFSA, in record time, concluded that, based on the available information, the potential risk of contamination posed by the volcanic ash fall to drinking water, vegetables, fruit, fish, milk, meat and feed was negligible.

Finally, the closure of the European airspace disrupted the travel of many third-country nationals, who are subject to strict visa requirements during their stay or transit through the territory of the Schengen states. Urgent derogatory measures were taken for certain categories of travellers and, in particular, for people holding a short stay visa that had expired on or after 15 April 2010 and others not intending but needing to enter a member state's territory.

The Not-yet European Sky

EU integration does not extend to air traffic management. Only member states can decide whether or not to close their airspace. As a result, the EU boasts twenty-seven different air traffic zones, each able to impose a flying ban.

This fragmentation is the result of a history of air traffic control remaining closely associated with sovereignty, and hence confined within national borders. Indeed, air traffic control is still perceived as governed by both national defence and sovereignty interests. This also reflects one of the tenets of the Chicago Convention, according to which each state is responsible for safety oversight in civil aviation within its jurisdiction.

Yet, efforts have been made toward integration of EU airspace. Following the adoption of the Single European Sky (SES I) legislation in 2004, air traffic management was brought under the EU common transport policy. The idea was to redesign the European sky according to traffic flows rather than national borders.

Yet, as unambiguously exemplified by the patchwork regulatory response to the current crisis, a truly 'single' sky has not been achieved.

To remedy this situation, another reform, the 'Single European Sky Package' (SES II), was adopted by the European Parliament and the Council in November 2009. To accelerate the full implementation of the SES II, the Commission seems ready to leverage the volcanic ash crisis to create political momentum.

In the aftermath of the crisis, the Commission issued a set of encouraging proposals. First, it proposed the creation of a European Aviation Crisis Coordination Cell (EACCC), gathering together EuroControl, European Air Safety Agency (EASA), member states and air transport stakeholders.

This is exactly what the EU did not have available during the crisis. The EACCC will mainly facilitate the management of crisis situations affecting aviation in the EU and will be empowered to launch unmanned aircraft vehicles (UAVs) to collect data.

Second, the Commission proposed the nomination of Functional Airspace Blocks (FAB) coordinators. FABs are nine airspace blocks based on operational requirements and established regardless of State boundaries, as foreseen in SES II.

Third, the Commission proposed that the central European network management be appointed by the end of 2010 and authorised to develop a more harmonised and coordinated approach to risk and flow/capacity assessment.


Although existing ICAO guidelines proved effective in preventing accidents in the wake of the recent eruption of the Eyjafjallajökull volcano, actions taken by national authorities resulted in unprecedented disruptions of service and severe economic impact to the airline industry, as well as to sectors relying on air transport services.

It became clear that more needed to be done to establish a safety risk assessment framework for determining whether it is safe to operate in airspace contaminated by volcanic ash.

At the urging of industry, ICAO agreed to form a multi-disciplinary International Volcanic Ash Task Force (IVATF), and terms of reference have since been agreed upon.

In light of its own experience, the European Commission has decided to elaborate a new methodology for safety risk assessment and risk management in relation to the closure of airspace, to be proposed to the next ICAO general assembly in September 2010.

In the meantime, by leveraging the disruption caused by the volcanic ash crisis, the Commission is likely to accelerate the implementation of SES II, thus institutionalising some of the ad hoc mechanisms and procedures developed during the eruption.

Undoubtedly, this crisis has added new impetus to the long-running struggle to unite Europe's airspace. As shown by this crisis, more than twenty years after the EU eliminated its internal land borders, the Union still lacks an integrated airspace. The time seems ripe for the EU to conquer its own sky."

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