Studying at Purdue University for a Masters. Lots of papers. Here is one on the eruption of Iceland’s volcano in 2010 that brought European airspace to its knees.
Abstract
Iceland’s eruption of Eyjafjallajökull (pronounced “A-ya-fyat-la-yœk-utl”) in April and May of 2010 spewed volcanic ash high into an eastward-moving jet stream, paralyzing Europe’s airspace located directly downwind. The eruption released 750 metric tons of volcanic ash and debris every second, creating a volcanic plume topping at over 30,000 feet. However, the presence of volcanic ash did not bring European airspace to its knees, but the lack of existing procedures and collaboration. With dynamic changing meteorological conditions, decisions became improvised. This paper will touch on the perils of volcanic ash and discuss how Europe became entwined in indecisions; it invariably could not overturn the closure of its airspace. The mismanagement culminated to the point where some airlines took things into their own hands to get airplanes flying again.
Keywords: Volcanic ash, Iceland volcano, European airspace, Eyjafjallajökull, air travel
Introduction
Worldwide some 60 volcanoes erupt each year. Only about ten volcanoes erupt ash plumes to heights exceeding 26,000 feet above sea level. Eyjafjallajökull’s tephra (Greek for ash and projectiles) ascended to 28,000 – 33,000 feet. At the time, the eruption- deemed moderate in intensity, instigated the most significant aviation shut down in history. The upper winds spread fine volcanic ash over Central Europe, Great Britain, and Scandinavia, forcing most European airspace closure. The magnitude of impact proved immense as the eruption “caused the cancellation of 108,000 flights, disrupted the travel plans of 10.5 million passengers, and cost the airline industry in excess of $1.7 billion in lost revenue (Budd et al., 2011). Perishable foods rotted, trade and services dwindled, and it all happened during the Easter holidays when tourism travel is high. Over 300 airports in nearly 25 countries and the corresponding airspace closed from April 15 to April 21. But could much of this have been avoided? The Eyjafjallajökull 2010 crisis highlighted the societal demand for unaffected mobility and aviation vulnerability to natural hazards (Hirtl et al., 2020).
Science, governance, organizations, policies, and economic imperatives became so convoluted its twisted knot choked aviation in Europe and caused ramifications worldwide. There was no consensus as to how to interpret the wider scale of the event; no consensus as to the amount of ash, its direction, or the acceptable level of ash in the atmosphere for aircraft to fly; and no consensus as to the consequences of partially or fully reopening airspace (O’Regan, 2011).
The make-up of ash
When visualizing ash, one may picture soft, fluffy material created by burning wood or paper. But volcanic ash is composed of hard, pulverized rock and minerals and sharp-edged glass. It does not dissolve, but readily absorbs water, is extremely abrasive, mildly corrosive, and conducts electricity when wet causing arcing and short circuits. Volcanic ash can be like talcum powder in size and texture but is much more abrasive. It’s equivalent in hardness to quartz — which can sandblast an aircraft’s aluminum skin and glass!
Perils of volcanic ash
The 1980 eruption of Mount St. Helens in Washington State brought the perils of volcanic ash to the forefront. A three-engine Boeing 727 and a four-engine DC-8 encountered windscreen damage and damage to other systems, but both aircraft managed to land safely. This eruption also set the precedence for issuing volcanic ash SIGMETs (Significant Meteorology).
Two years after Mount St. Helens erupted, a British Airway’s B747 (Flight 009) encountered a four-engine flame-out due to volcanic ash over Java, Indonesia. In 1989, yet another B747 (KLM Flight 867) experienced a four-engine flame-out on approach into Anchorage, Alaska, plus, they also had false fire warnings in the cargo holds (Hirtl et al., 2020). Incidentally, both aircraft recovered their engines and landed safely, but damage surpassed in the multi-millions.
Figure 1: Effects of volcanic ash. (Source: Dennstaedt, 2018)
Volcanic ash hazards
- Ash sandblasts and causes crazing (scratching) of the wing’s leading edges, windscreens, windows, navigation, and landing lights.
- The smell of sulfur, acrid odor, or burning electrical smell may be present.
- Volcanic dust deposits and smoke in the flight deck and cabin may be present.
- Electrostatic discharge (St. Elmo’s fire) on the windshield, nose, or engine cowls and a bright glow in engine inlets is another precursor to the presence of volcanic ash.
- It affects instrumentation and internal systems when ash infiltrates the pitot tubes and static ports, causing a decrease in or loss of indicated airspeed.
- Pressurization outflow valves, filters, vents, air-conditioning packs, and bleed air systems can become clogged. A loss of cabin pressure may ensue with false cargo fire warnings that may be triggered.
- For both aircrew and passengers, the effect on the human body may become a significant health issue.
- Engine fluctuations, compressor stalls or surges, high-temperature exceedances are precursors to partial or complete engine failures – the most significant hazard of ash!
Volcanic ash has a melting point of about 1150° C, which is within most turbine engines’ operating temperatures. As ash enters the highly susceptible precision jet engine innards, it tends to melt, clogging fuel nozzles, nozzle guide vanes, and other small orifices. At one time, when engines began to fail, the procedure required increasing power, which made a peril situation worse. Now most airliner’s volcanic ash checklists are to exit the ash as quickly as possible, which may mean a descending turn or reverse course, disengage the autothrottles, and, if able, bring the engines to near idle thrust to prevent further damage. When out of the ash and flying into an inrush of clean, cold air, the glass will shatter and hopefully unclog the engines.
VAACs (Volcanic Ash Advisory Centers)
After realizing the danger of volcanic ash, and from previous incidents, the International Civil Aviation Organization (ICAO) and the World Meteorological Organization (WMO) created nine Volcanic Ash Advisory Centers (VAACs) to monitor and forecast the dispersion of fine ash in the atmosphere. In Europe, the London VAAC (UK Met Office) and the Toulouse VAAC (Météo-France) assumed responsibility to operate a 24/7 service (Hirtl, 2020).
Figure 2 Nine VAACs (Volcanic Ash Advisory Centers) (Source: Dennstaedt, 2018)
The ash fall out – eruption disruptions
The London Volcanic Ash Advisory Center, under the direction of ICAO, took on the daunting task of forecasting the whereabouts, intensity, and threat of Eyjafjallajökull’s fall out. In response, the ICAO, which operates the International Airways Volcano Watch system, recommended implementing a no‐fly zone when volcanic ash is detectable in the airspace. The evidence that volcanic ash could seriously damage plane engines and cause great financial cost to airlines meant a universal adoption of the ‘no threshold’ guideline (O’Reagan, 2011).
On a side note, in 2012, I approached four of the nine VAACs to have a chapter on volcanic ash proofread. All four VAACs deemed the request contentious. Ironically, the main reason VAACs exist is for aviation safety.
The London VAAC abided by ICAO’s guidance manual stating pilots should avoid all ash plumes without exception. This generalization closed the second busiest airspace on the planet, with the northeastern USA being the busiest. It not only stranded passengers in Europe, but across the world. According to (O’Regan, 2011) critics noted that the computer model, NAME (Numerical Atmospheric‐dispersion Modelling Environment), used to predict the spread of ash proved unable to map the location of the volcanic ash cloud precisely. No matter the poor performance of the computer models, the CAA (Civil Aviation Authority) advised NATS (National Air Traffic Services) to close – collectively canceling all flights. Aviation is unequivocally a complex system, but numerous other agencies became entangled, thereby stifling any suggestion to unravel the mess. The tangled web grew within Europe’s multitude of governing bodies. No one knew who had authority over what. Only an illusion of control existed, with no one taking the reins to manage the closures and address the resumption of flights. Sadly, airlines, engine makers, scientists, meteorologists, aircraft manufacturers, safety regulators, or any governing policymaker could not find a way out of this airspace closure conundrum. As the closures remained – politicians, airlines, weather experts, the scientific community, newspapers, travel agents, and engineers gave conflicting advice, ‘immutable mobiles’ such as now infamous ash cloud maps and charts allowing absent experts as well as officials to ‘act at a distance’ upon the travel plans of millions (Latour, 1987).
Why the fiasco?
The British government entered the crisis with no reliable data on ash concentrations in the European atmosphere and none on levels at which it was safe to fly. The result was a form of risk aversion, which prevailed until better information was made available (Alexander, 2013). The wait and see philosophy proved only the beginning. One would think the VAACs would have had meteorological ash concentration standards to determine what ash concentrations are deemed safe, medium risk, or treacherous to airlines.
Initially, all flights were grounded in areas covered by the ash cloud containing at least 200 μg/m3 (low risk). It’s a low value, i.e., only 200 micrograms can exist in a cubic meter of air. However, a jet engine can suck the air out of a house in one second! By April 20th, the threshold had been raised by one order of magnitude to 2000 μg/m3 (medium risk). But serious damage to jet engines begins at concentrations approaching three orders of magnitude higher — 2 g/m3 (high risk). The thresholds selected (200 and 2000 μg/m3) did not have an adequate justification in terms of science or flight engineering (Alexander, 2013).
But there is more to why the situation became more mired and adding to the confusion. Jet engine and aircraft manufacturers did not have definite jet engine limitations. No one truly knew for sure what concentration of ash caused jet engines to falter or fail. The zero-tolerance policy for flying through volcanic ash hadn’t been challenged or updated. According to (Morton, 2017), before Eyjafjallajökull’s 2010 eruption, airlines and engine manufacturers had mostly sidestepped the issue of testing the effects of ash on engines. “Nobody wanted to be responsible for testing it,” says Ulrich Kueppers, a volcanologist at Ludwig-Maximilians University in Munich, Germany. “Airlines deferred to the turbine manufacturers, and turbine manufacturers said they don’t need to test the effects of ash because there is no regulation requiring it.” And so, the blame game continued.
Airlines revolt
Because of the plethora of governing agencies involved, no governing agency nor procedure existed to make definitive decisions. The risk aversion succumbed to improvisation with little scientific justification. Airlines, inconvenienced passengers, and the public started protesting about the closures. This situation became further exacerbated by volcanologists’ prognosis reported in the news that the possibility existed for an extended eruption of Eyjafjallajökull (Bolić, 2010). Things became heated as British Airways taunted the British government by flying a B747 from Bristol to Scotland and return with no repercussions. Lufthansa and Air Berlin followed suit. On the morning of April 18, about six days into the airspace closure, KLM successfully flew a test flight from Amsterdam to Düsseldorf. Air France also performed a trial flight from Paris to Toulouse, France. Stranded passengers became confused, dumbfounded, and angry. They saw blue skies and couldn’t comprehend the danger.
Long after airlines performed their own test flights and were calling on authorities to reconsider blanket airspace closings, national authorities dragged their feet, even when the crisis showed how quickly Europe would flounder if it didn’t get the airspace up and running.
I appeared on Canada’s national weather channel, the Weather Network, to explain the situation from a pilot/meteorologist’s viewpoint. I mentioned that even though the ash layer lingered between 28,000 to 30,000 feet, airliners had to climb or descend through it. Viewers also wanted to know why weather radar couldn’t detect the ash. Weather radar reflectivity for ash is roughly one-millionth compared to cloud droplets; thus, an onboard weather radar could not detect volcanic ash. Frustration escalated – Canadian passengers and aircrew sat at overcrowded airports and cooped up in hotels desperately wanting to fly, but couldn’t understand why airplanes remained grounded.
One interesting curveball during the shutdown is the winds aloft shifted. A rare easterly wind carried volcanic ash over the Atlantic Ocean to Canada’s eastern airspace but proved insignificant.
Like any situation of this scale, 20/20 hindsight revealed things could have played out much differently. Authorities should have developed a risk management system that defined no-fly zones by the concentration of ash in the air, instead of relying on a cart-blanche no-fly policy based on mathematical models of ash dispersion. Finally, a new larger threshold of 2000 micrograms of ash per cubic meter or 0.002g/m3 of ash received a stamp of approval, and European airspace progressively reopened from April 20. A new authority also emerged, the International Airways Volcano Watch (IAVW), and with it, new ICAO procedures and guidelines.
After the ash settled
In May, and after a second and much smaller eruption from Eyjafjallajökull, the European Aviation Safety Agency (EASA) finally drafted volcanic ash procedures into four fly zones:
1. A white zone where normal flight operations apply.
2. A red zone in which some volcanic ash may be encountered but flights can still fly.
3. A gray zone in which EASA allows flights but under certain conditions.
4. A black zone (no fly) in which EASA recommends banning flights because predicted ash concentrations exceed acceptable engine manufacturer tolerance levels (Bolić, 2010).
A decade later, a similar scene: COVID-19
We are upon another aviation catastrophe. Eyjafjallajökull’s induced economic loss pales to our present-day situation. But here we are again. We see governing authorities unsure how to govern, doctors and scientists sending out conflicting information, and airplane manufacturers averring it is safe in an airplane regarding COVID. The airlines want to get back into the skies, but few at the helm can make it happen. People and airline employees are getting angry and losing jobs; politicians are bombarded with letters and concerns, IATA (International Air Transport Association) are canvassing governments. It’s déjà vu all over regarding getting mired in policies, opinions, and keeping the status quo.
Conclusions
Since Eyjafjallajökull’s 2010 outbreak in Iceland and the resulting closing of vast areas of the European airspace for days, changes have been made to the standards and recommended practices of aviation volcanic eruptions. Until this event, the maxim was “avoid visible ash” as an answer to the flights of two Boeing 747s that flew into ash clouds in the 1980s (Johnson and Casadevall, 1994). The Volcanic Ash Contingency Plan (VACP) now grants airspace users the power to decide whether to fly or not, based on their safety risk assessment accepted by the Civil Aviation Authority. In other words, it allows airlines to self-govern when contesting with volcanic ash. Consequently, most countries in Europe do not close their airspace as a default procedure in a volcanic eruption (Hirtl et al., 2020).
Eyjafjallajökull will be known as the volcano that caused the most disruption in the aviation world. It demonstrated how European authorities became uncoordinated with the eruption and too slow to respond. For example, it took European travel ministers five days to arrange a conference call to work out a viable solution. The European Union has over 20 airspaces, so it collectively must be ready for the next volcanic surprise.
Recommendations
Eruptions similar to or even more severe than that of Eyjafjallajökull are possible in Europe’s not-too-distant future. The dynamics of atmospheric circulation could cause relatively large changes in the pattern of ash concentration in only a few hours. Hence the concept of “safe corridors”—widely discussed during the Eyjafjallajökull crisis—is called into question (Alexander, 2013).
The list is long in lessons learned, but not only for European airspace. A volcanic catastrophe can occur in most parts of the world. Regulatory and international bodies must meet the problem head-on. A wait and see is not viable economically. Volcanic ash thresholds should be more rigorously defined. The new benchmark of 2000 micrograms/m3 of ash only applied to the European fiasco. Other VAACs must be on the same page. The new standard of air traffic control agencies must broaden their umbrella to include natural hazard impacts. Europe must develop a contingency plan if a mode of transportation becomes a non-viable option, as this fiasco showed a heavy reliance on the airline industry. More backups in the transportation industry are required. A simple risk aversion should not be the only answer for a volcanic eruption.
Pilot Weather Wisdom 
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