I write these notes in the middle of a crisis without precedent which includes the longest detained mandatory ( groundstop ) history of civil aviation in Europe. I write from a makeshift accommodation while waiting for the possibility of returning to Italy from London. While it would be too early to draw conclusions in this event, some preliminary observations can be made.
forms of explosive volcanic eruption called Vesuvius, Plinian ultrapliniana and are able to penetrate the stratosphere and inject large quantities of tiny particles of volcanic glass, which can remain suspended for several days. Moreover, as demonstrated by the eruption of the Mexican volcano El Chichon in 1982, also the volcanic gases such as sulfuric acid can severely damage aircraft (Bernard and Rose 1990).
Accidents most discussed are those of 1982 when two Boeing 747 aircraft flying from Jakarta to Australia who have suffered off engine and a rapid descent and unintended feathers when they flew into the ash produced by the eruption of Galunggung (Tootell 1985) and that of 1989 when a Boeing 747-400 suffered a similar impact (with U.S. $ 80 million in damages) and walked among the ashes of the eruption of Redoubt Volcano (Casadevall 1994a), Alaska. In all three cases, the incident has reached the level 4 on a scale (the "Ash Encounter Severity Index", AESI - ICAO 2001) from 0 to 5 (plane crash) of the fly in the face of danger effects volcanic.
However, in 25 years, 8 level 4 incidents have happened (ICAO 2001), compared with 43 Level 2 (moderate damage, but does not compromise functionality of the aircraft). These are i tipi di impatto sugli aerei riscontrati (Casadevall 1994b):
* danni ai rotori dei motori a reazione
* abrasione dei vetrini della cabina di controllo
* abrasione delle superficie del velivolo, abbassando le sue prestazioni in volo
* compromissione del funzionamento della strumentazione a bordo
* danni ai sistemi di raffreddamento e di aria condizionata
* contaminazione del carburante.
Gli effetti sono potenzialmente catastrofici (Grindle e Burcham 2003), ma non è ancora successo un disastro di livello 5 dell'AESI, malgrado l'eruzione ogni anno di ben 50 vulcani su 500 potenzialmente attivi, e l'ubiquità dell'aviazione civile nel mondo.
Per iniziare, la sicurezza dell'aviazione civile di fronte all'emissione delle ceneri da vulcani in eruzione è un problema ben conosciuto che vanta di 25 anni di studio e diversi manuali (Shun et alii 2009) e simposi (Casadevall 1994b). I lavori pubblicati comprendono studi della teleosservazione delle eruzioni finalizzata al preavviso (ad es. Corradini et alii 2008), studi di particolari situazioni (ad es. Casadevall et alii 1996) e piani di emergenza per affrontare situazioni di particolare rischio o contingenza (ad es. CNMI 2009). Esiste un modello matematico di simulazione e monitoraggio del problema, PUFF, il quale segue la dispersione delle ceneri nell'atmosfera con una formulazione Lagrangiana di avvezione, caduta e diffusione turbolente (Searcy et alii 1998).
The risk posed by volcanic island is well known (Pieri et al 2002), but in northern Europe in mid-April of 2010 there is a noticeable lack of initial planning and a tendency to underestimate the risk. Thus, the national register of risks, contingency planning vital documentation of the British government (UK Cabinet Office 2010), does not speak of the volcanic hazard to aviation. In fact, the only risk to aviation addressed in this document is that of terrorism. About
Eyjafjallajökull rash, the British government has called the level "platinum" command and control (COBRA, Cabinet Office Briefing Room, the highest level of system Civil Protection) at 8:30 of Monday, April 19, for a crisis that began at noon on Thursday, April 15. The delay, in my opinion it shows a tendency to underestimate the crisis, a form of normalcy bias (Omer and Alon 1994) of collective government and managers of the national civil protection.
There is sufficient portability between the various means of public transport (air, train, bus, ferry, etc..) Does not exist in Europe and a contingency plan to move masses of people remain fixed for the cessation of a media transport. The result is a response to very weak and inefficient. Meanwhile, some travel needs, such as the transport of bone marrow transplant, they put lives in danger.
In the UK the government and the media talk a lot about the repatriation of British citizens remained abroad. But according to every principle of equity in the relief effort should speak for the movement of all people in need.
How are telling the industry of civil aviation, it seems that the strategy of total closure of airports to 22 European countries has been based on risk aversion (Schneider 2006) rather than analysis the situation accurately, which came after. The use of diffusion models and synoptic teleosservazione produces results and include, but not necessarily decisive. A low concentration of ash is likely that the biggest problem would be the maintenance area, tools and equipment subject to abrasion and the accumulation of particulates. But with the passage of time, the costs of facing the risk of flight decreases rapidly in the loss of income for daily passengers.
In conclusion, what is needed is a European plan to address future risks to aviation due to Plinian eruptions, and volcanoes such as Vesuvius, Volcano and Santorini, not only in northern Europe. The plan should require rapid and decisive action, which includes the careful scientific monitoring of risk and the planned replacement of transport modes per meglio garantire lo spostamento delle persone che hanno necessità inevitabile di spostarsi.
Citazioni
Bernard, A. and W.I. Rose Jr 1990. The injection of sulphuric acid aerosols into the stratosphere by the El Chichón volcano and its related hazards to the international air traffic. Natural Hazards 3(1): 59-68.
Casadevall, T.J. 1994a. The 1989–1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations. Journal of Volcanology and Geothermal Research 62(1-4): 301-316.
Casadevall, T.J. (ed.) 1994b. Volcanic Ash and Aviation Safety: Proceedings of the First International Symposium . U.S. Geological Survey Bulletin no. 2047, 450p.
Casadevall, T.J., P.J. Delos Reyes and D.J. Schneider 1996. The 1991 Pinatubo eruptions and their effects on aircraft operations. Fire and Mud: Eruptions and Lahars of Mount Pinatubo, Philippines . US Geological Survey, Philippine Institute of Volcanology and Seismology, Manila.
CNMI 2009. Interagency Operating Plan for Volcanic-ash Hazards to Aviation in the Pacific Region of the Northern Mariana Islands . Commonwealth of the Northern Mariana Islands Emergency Management Office, Guam, 29 pp.
Corradini, S., C. Spinetti, E. Carboni, C. Tirelli, M.F. Buongiorno, S. Pugnaghi and G. Gangale 2008. Mt. Etna tropospheric ash retrieval and sensitivity analysis using Moderate Resolution Imaging Spectroradiometer measurements. Journal of Applied Remote Sensing 2: paper 023550.
Grindle, T.J. and F.W. Burcham Jr 2003. Engine Damage to A NASA DC-8-72 Airplane From a High-Altitude Encounter with a Diffuse Volcanic Ash Cloud . Technical Manual NASA/TM-2003-212030. NASA Center for Aerospace Information, Hannover, Maryland, 22 pp.
ICAO 2001. Manual on Volcanic Ash, Material and Toxic Chemical Clouds . Document no. 9766-AN/954. International Civil Aviation Organisation.
Omer, H. and N. Alon 1994. The continuity principle: a unified approach to disaster and trauma. American Journal of Community Psychology 22(2): 273-287.
Pieri, D., C. Ma, J.J. Simpson, G. Hufford, T. Grindle and C. Grove 2002. Analyses of in-situ airborne volcanic ash from the February 2000 eruption of Hekla Volcano, Iceland. Geophysical Research Letters 29(16): 19.1-19.4.
Searcy, C., K. Dean and W. Stringer 1998. PUFF: a high-resolution volcanic ash tracking model. Journal of Volcanology and Geothermal Research 80(1): 1-16.
Schneider, T. 2006. Risk aversion: a delicate issue in risk assessment. In W.J. Ammann, S. Dannenmann and L. Vulliet (eds) Risk 21: Coping with Risks Due to Natural Hazards in the 21st Century . A.A. Balkema, Taylor and Francis, London: 59-66.
Shun, C.M., I. Lisk, C. McLeod and K.L. Johnston 2009. Meteorological services to aviation. Bulletin of the World Meteorological Organization 58(2): 94-103
Tootell, E. 1985. "All Four Engines Have Failed": The True and Triumphant Story of Flight BA 009 and the Jakarta Incident . Pan Books, London, 178 pp.
UK Cabinet Office 2010. National Risk Register of Civil Emergencies . Cabinet Office of the United Kingdom Government, London, 56 pp.
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