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Volcanic Ash

Ashes to Ashes - What has been learned from recent volcanic eruptions and where does the industry go from here? 

About 500 volcanoes are listed as active and about 50 typically erupt each year. Not surprisingly, aviation is no stranger to volcanic activity.

Arguably the most famous case occurred in 1982, when a British Airways Boeing 747 flew into an ash cloud from the Galunggung volcano, Indonesia. The aircraft lost power in all four engines but managed to restart them just in time to make a safe landing in Jakarta. And there are regular disruptions elsewhere in the world. Mount Redoubt has long caused problems for flights to and from Anchorage, Alaska, for example—most notably in 1989 when a KLM flight sustained an estimated $80 million in damages.

Yet, despite such familiarity, the eruption in April 2010 of Icelandic volcano Eyjafjallajökull hit the industry like a bolt from the blue. It was the first significant incident in dense airspace for some time and has heightened awareness of the hazard. During a period of seven days, some 100,000 flights were cancelled as civil aviation authorities shut down airspace across Europe. The region did a lot better earlier this year when a second Icelandic volcano, Grimsvötn, erupted—but the 2010 uncertainty and chaos resulting from the draconian measures ended up costing the industry $1.8 billion and the global economy approximately $5 billion.

It was all very different when a volcano in the Puyehue‑Cordón Caulle chain in Chile vented its spleen. GOL and LAN flights to Buenos Aires were among those affected, and the cloud even reached as far as Australia, causing airlines there to cancel services. But, crucially, the decisions about whether or not to fly were made by the airlines, not the aviation authorities. The chaos associated with the 2010 European eruption was nowhere to be seen. Even though different decisions were made by Qantas, Air New Zealand, and Virgin Australia, safety was never compromised, and communication with customers was clear. Generally speaking, passengers were informed about their flight status before they set off for the airport.

Beyond the cloud

The challenge now is to convert these learning experiences into best practice for the future. While there has always been guidance available to airlines and air traffic management (ATM) at the International Civil Aviation Organization (ICAO) level, it must be better defined to deal with the different situations. Proscriptive airspace closures by governments are not the solution. Established safety management systems that allow airlines to make operational decisions based on available data represent the best path forward.

There is a wider context, too. With traffic continuing to grow rapidly, and the airlines continuing to invest in more advanced avionics, the air traffic system is under increasing pressure to fulfil the needs of operators and the industry. Careful coordination between the requirements of the operators and the capability of the ATM system is necessary, now and in the future.

A useful start would be to determine a ‘safe’ concentration level for an ash cloud. Roger Dinius, Chief Consulting Engineer at GE Aviation, warns this won’t be easy. There are complexities to be overcome on the aircraft certification side as well as on the precise location and concentration measurement of the ash cloud. “Abstract phrases such as ‘safety limit’ have little meaning without a practical way for the operator to use them,” says Dinius. “Volcanic ash particle size, exposure time, and engine power setting are some of the factors that need to be accounted for in any proposed safety limit.” 

Every aircraft part reacts differently to the presence of ash. Even within engines there are many potential outcomes. “In the worst-case scenario, volcanic ash could lead to an engine stall or flame-out caused by a blockage of the turbine nozzles and vanes that are critical to airflow and pressure in an engine,” explains Dinius. “Volcanic ash will wear down many parts of the engine, causing a loss of efficiency and ability to produce thrust. Additionally, ash can block cooling holes and contaminate the oil system, which can significantly reduce engine life.”

The minute particles of glassy, abrasive rock that constitute an ash cloud don’t just clog up an engine. Windshield abrasion is commonplace, as is damage to an aircraft’s navigational and communication systems. Furthermore, different volcanoes produce different particles, so any particular ash cloud may be more or less abrasive, and affect aircraft in different ways. It is impossible to set one clearly defined limit.

Ash cloud guidelines

Fortunately, this impenetrable conundrum won’t consign airlines to a future of airspace closures. “Because it’s hard to define an exact limit, we are working towards the recognition that risk assessment processes, such as those used for other natural hazards, are sufficient for airlines to determine whether or not it is safe to fly,” says Mike Comber, IATA Director for ICAO Relations.

The work is being undertaken one step at a time through the ICAO International Volcanic Ash Task Force (IVATF), which includes all the relevant parties, including original equipment manufacturers. IATA is active in those discussions, with a presence in all the sub-groups. The IATA team includes three staff members and six airline colleagues. The IVATF has recently held its second meeting and produced a number of proposals to enhance efficiency. IATA is also working with airlines to incorporate volcanic ash guidelines within safety management systems, and is reviewing the IATA Operational Safety Audit with a view to including a reference to the ash cloud hazard.

The move to risk assessment

But all of the airlines’ work will be undone if regulators fail to heed the lessons learned and instead continue with blanket airspace closures based on theoretical projections of ash clouds such as those employed during the Eyjafjallajökull eruption. Fortunately, matters appear to be heading in the right direction. When Grimsvötn threatened airlines earlier in 2011, European states were far more restrained, airspace for the most part remained open, and disruptions were localized.

“Lessons have been learned,” says Olivier Jankovec, Director General of Airports Council International Europe. “This past year, the European Commission, Eurocontrol, and the European Aviation Safety Agency have worked intensely to devise an alternative procedure for flight operations, safeguarding the highest possible level of safety while minimizing disruption. This procedure is at the disposal of national governments. It now needs to be applied promptly and consistently throughout Europe.”

Without the promised movement on a Single European Sky, the patchwork of inconsistency remains a stumbling block, but Comber stresses that IATA has been actively ensuring political understanding of the issue. “We have been working hard with governments to shift the decision to airlines, and stakeholders have realized that operators are best placed to make the call,” he notes. “Airlines are happy to take on this responsibility. It’s nothing new. Most of them have been flying for a long time in areas subject to volcanic ash. They are used to making informed safety decisions based on strong processes, applicable data, and solid experience.”

Comber adds that the airline industry has been unified in its submissions to the IVATF, and this cooperation is underscored by a strong airline participation in the IATA delegation to the Task Force.
Longer term, airlines need improved data from scientists. Detailed research could allow the industry to get better at predicting volcanoes, analyzing eruptions, and determining the nature and location of the ash cloud. Better understanding of airframe and engine tolerance from the design stage will also be a key factor. “We’re getting better at these ‘when’, ‘what’, and ‘where’ questions,” agrees Comber. “The more information we get, the more refined decisions we can make.”

And with that comes the kind of certainty airlines and their customers have been crying out for.


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