Volcanoes represent a potential risk for aviation, which to date has already resulted in multimillion-dollar losses due to the need to close airspace affected by an eruption or the ash resulting from it, but above all they are events that must be prevented to promote the safety of flights.
Over the past 50 years, more than a hundred commercial aircraft have experienced incidents during flight due to volcanic clouds. Among the best-known incidents is the case of a British Airways Boeing 747 whose four engines were shut down in June 1982 while it was passing through Indonesia. Another KLM 747 suffered exactly the same type of incident over Alaska a few years later. The volcanoes Galunggung and Redoubt were the culprits in each case.
Few spectacles in nature are as breathtaking as the eruption of a volcano. If the scene can be seen at night, believe me, it is one that is not easily forgotten. However, as in other facets of life, what brings us beauty on the one hand, threatens us on the other. For, in addition to the danger posed by the eruption itself, there is a risk that particularly affects the aeronautical world: ash clouds.
There is a recent episode that has enjoyed a prominence and follow-up never before given to this type of phenomena: The eruption of the Eyjafjallajökul volcano (Iceland) in 2010. But there are many others less relevant, such as those of Popocatépel (Mexico), Etna (Italy), Sangeang Api (Indonesia), Puyehue (Chile) or Ubinas (Peru), as well as dozens more, whose effects have been, among others, the suppression of aircraft flights in their vicinity due to the threat posed by ash emissions.
The case of the Icelandic volcano was particularly significant. It gave rise to to the further closure of airspace since World War II, with an impact on European airlines of 1.7 billion euros and an effect on global GDP of almost 5 billion euros.
Contrary to what some people think, the problem is not the remote possibility that the eruption will literally overwhelm an aircraft passing overhead, or that the heat of the molten lava (between 700 and 1,200 degrees Celsius) could melt any object passing vertically. It is unlikely that a plane will be allowed to get close enough to a volcano for any of this to happen. The danger we are talking about, and whose geographical scope can be continental in scopeis that of the ash expelled by the volcano.
But why can volcanic ash be dangerous for aircraft?
There are four main reasons:
- The ash can accumulate and melt inside jet engines, which exceed the melting temperature of the particles inside the engine. This can lead to the creation of new crystals which, if they adhere to certain parts of the engine, could cause its collapse.
- The ash is very abrasiveThe use of the engine, which can damage sensitive engine parts, can lead to the same result as above.
- They can cause erroneous readings of aircraft operation
- The invisibility of some ash cloudswhich, due to their low density or particle size, may not be perceptible to the human eye (their size usually ranges from 500 microns to 2 millimetres).
Not all volcanoes are potentially dangerous in this sense. The "Hawaiian" type, some of which are among the most historically active, do not emit ash. However, the "Vulcanians or Vesuvians"They are really threatening both because of the type of eruption and because of the usual emission of ash and other associated phenomena.
In view of the evidence of some aeronautical incidents, such as those mentioned above, caused by ash clouds, ICAO, in collaboration with WMO (World Meteorological Organization), established in 1987 the IAVW (International Airways Volcano Watch) to monitor the potential hazards to air traffic from volcanoes on a global level. Since that time, a series of operational directives and procedures aimed at minimising the impact of eruptions and increasing safety.
In the 1980s, the ICAO set up a specific monitoring office for volcanic phenomena.
Since the Icelandic volcano event in 2010, the ICAO has also mandated the IVATF (International Volcanic Ash Task Force) to assess the needs of civil aviation to anticipate such events.as well as to determine the necessary actions in each case. It also designated nine specialised zonal meteorological centres as volcanic ash control points (London, Toulouse, Montreal, Washington, Anchorage, Tokyo, Darwin, Wellington and Buenos Aires). These centres generally disseminate three standard types of information:
- Notice volcanic ash, VAA
- Graph volcanic ash, VAG
- Predictive model of its trajectory, HYSPLIT
In parallel to the work of official bodies, there are also companies that are devoting a significant R&D effort to the development of new and improved tools for early detection the possible presence of volcanic ash in the air and thus take preventive action.
A success story It was noteworthy that a group led by Airbus carried out this project, in which companies such as Easyjet and Nicarnica Aviation also participated. They successfully tested a system called AVOID That, installed on a plane, was able to detect the presence of ash 60 km ahead of the aircraft. And not only that, but it also provided advance data on its density, concentration, and mobility. Having these data in advance allows not only to alert the crew about the possible risk, but also to put in place an appropriate protocol that allows minimizing its impact on the flight.
The AVOID system is a device that provides real-time data based on rapid sampling of infrared-synchronized camera images. Once the information is obtained, it is combined with GPS data and air speed data, resulting in a three-dimensional map of the ash cloud and its predicted trajectory. This technology allows, depending on the concentration of ash, detections ranging from 50 to 100 km, both day and night. At conventional cruising speed, this allows a 7-10 minute lead to the aircraft pilot.
R&D efforts are focused on obtaining predictive information on the nature and mobility of ash clouds.
This information is not only useful for the aircraft itself, which detects and processes it, but it can also be used to share with the zonal centres and thus keep other aircraft without the system informed.
Contrary to what some may fantasise, most natural phenomena cannot be mastered. But there is no doubt that technology and knowledge are key factors for minimising its impact. For its part, the aeronautical industry has, among its priority objectives, to adopt appropriate measures in the fields of information, organisation, prevention and innovation in order to maintaining security at its highest level.
