The eruption of the Icelandic volcano Eyjafjallajökull halted European air traffic for a week, affecting 1.2 million passengers a day. We discussed the event with Mirko Komac, director of the Civil Aviation Directorate at the Ministry of Transport.

There are, of course, different views of the situation. Several groups are involved here, with different objectives. On the one hand are the ministries and the agencies responsible for aviation safety, then there are the commercial entities, whose first priority is their own profit, and then there are the passengers, whose primary concern is getting from A to B with as little hassle as possible. In the case of this volcanic eruption, it was the latter two groups – the airlines and passengers – who drew the short straw. And who was the cause of this inconvenience? On the basis of Article 11(2) of the Aviation Act, the Ministry of Transport is the body that holds the authority to issue a decision limiting or prohibiting flying in Slovenia. Naturally there need to be proper grounds for such a decision. In view of the fact that the cloud of volcanic ash reached Slovenia a day later than the northern part of Europe, the situation was already being closely monitored here. Ministry staff were in constant contact with the Aviation Meteorology Service (SLM) at the Environmental Agency of the Republic of Slovenia and with Slovenia Air Traffic Control (KZPS), which in turn were in contact with the responsible European institutions. Data on the quantity of volcanic ash was provided by the London Volcanic Ash Advisory Centre, which in accordance with international conventions is responsible for monitoring volcanic eruptions in northern Europe. On the basis of these data it was decided, in conjunction with the SLM and KZPS, to close Slovenia’s airspace at 11.00 p.m. on 16 April. This decision was justified. Safety is of first importance in air transport, and the interests of the individual entities involved can be no different. According to Komac, the same decision would be taken today if the same data were available. In the light of experience gained, however, even now decisions are being taken on the basis of new findings based on scientific research. A number of scientific institutions in Europe and the USA have carried out test flights that have revealed the presence of ash particles in the air and shown their influence on aircraft and their systems. One such institution is the German Aerospace Centre (DLR), which has carried out quite a number of flights over Germany using a specially equiped Falcon 20E aircraft. Particles with a diameter of more than 3 micrometres were detected, but their density changed rapidly. No damage to the aircraft or its engines was observed. Swiss airborne measurements company MetAir has also carried out test flights and reported reduced visibility in the ash cloud and rapid changes in the quantity of particles in the air. Some years ago, US space agency NASA has its own experience of flying through volcanic dust. In February 2008 a NASA DC-8 happens to fly through a cloud of volcanic ash without the crew even noticing. Post-flight analysis of the state of the engines revealed that the ash had clogged the holes on the turbine blades (through which colder air flows to cool the blades) and stuck to the blades’ surface. The costs of repairing the engines came to $3.2 million, even though the aircraft was flying 360 kilometres away from the centre of the ash cloud. Since 19 April NASA has been using a satellite to monitor the quantity of sulphur dioxide (SO2) in the atmosphere above Europe. SO2 is a fairly reliable indicator of the concentration of volcanic ash in the air (see picture). Data from the EOS Aura satellite are much more reliable than established observation-based methods, both radar and visual. The International Civil Aviation Organisation (ICAO) has in fact dealt with 80 cases of aircraft flying through ash clouds in the last 15 years. Fortunately there have been no accidents.

Anxious to keep the loss of revenue of the aviation industry to a minimum in these already difficult times, European transport ministers held a video conference during the flight ban. On the basis of scientific research they considered three ways of resolving this unsustainable situation. Three options were presented. The first was a total closure of airspace. The second involved a partial closure of airspace within a 110-kilometre radius of the ash cloud, along with compulsory inspections of aircraft engines and other systems that could be damaged by the ash. In this case the final decision on whether to fly would be left to the pilot. The third option was a complete liberalisation of flying, with meteorological and navigation services providing all necessary information and the airlines themselves deciding whether or not to fly, thus assuming all responsibility for safety and potential consequences. The ministers chose the second option. As regards the reimbursement of aviation organisations (airlines, airports and other aviation-related entities) and passengers, Komac explains that the rules on aid to legal entities are established in the Treaty on the Functioning of the European Union (Point 2(b) of Article 107 allows aid to make good the damage caused by natural disasters or exceptional occurrences), while the rights of passengers in the event of flight cancellations and delays are covered by Regulation (EC) No 261/2004[1] and Regulation (EC) No 889/2002 of the European Parliament and of the Council.[2]. The Civil Aviation Directorate has invited all legal entities operating in Slovenia affected by the situation to submit a report on the damage they have suffered. The ministry will process this information and forward it to the government, which will decide on the level of any compensation. European practice will also be followed in this process. Passengers who have incurred costs as a result of this situation should apply to the travel agent or tour operator who sold them the air ticket or package tour, or directly to the airline from which they purchased their ticket.

The competent bodies will continue to work in the public interest, for the safety of passengers and third parties, even if this means that public interest comes into conflict with commercial interests. It is precisely because of this attitude and scrupulous respect for the rules, concluded Komac, that aviation is the safest means of transport for passengers and cargo.