Ash Cloud Studies Yield Suggestions

Improved measurements of volcanic ash and better communications among aviation stakeholders are required to lessen the transportation impact of ash clouds such as occurred last April when Iceland’s Eyjafjallajokull volcano spewed gas-charged lava that exploded and sent a stream of ash into European airspace.

Specific recommendations are contained in two papers scheduled for presentation at the Transportation Research Board’s (TRB) 2011 annual meeting starting Jan. 24 in Washington. University of Iceland professor Gudmundur Freyr Ulfarsson says current ash cloud forecast models function with limited information. He suggests that was why authorities created large buffer areas around no-fly zones that may have resulted in unnecessary flight cancellations.

“This was highlighted by airline complaints of too extensive closures of airspace and airports, and administratively recognized by the shifting of the no-fly zone into higher modeled ash concentrations,” he wrote in his paper, a case study of the impact of the volcanic eruption co-authored by Ph.D. candidate Elizabeth Unger.

Ulfarsson says ash concentrations were not measured continuously at fixed, regular intervals. He recommends that ash concentrations be measured at different altitudes and ash granularity and dispersion be gauged on a real-time basis. This need, he says, raises questions of costs and who is to bear it. He recommends that stakeholders join in an international effort to finance improved measurements and new procedures.

The volcanic event also led to the revelation that not all engines are certified to contamination in the air. The European Aviation Safety Agency has begun a program which needs research to understand the effects and characteristics of ash damage to jet engine and other aircraft parts, the professor says.

Ulfarsson recommends that stakeholders conduct an exercise to test their responses and management in case of another event. He says the European Commission has indicated that it may allow airlines to make the decision to operate in ash-contaminated airspace, a possible shift in policy that now rests with public agencies. He also suggests updating the Notice to Airmen system.

In a lessons learned paper, Tatjana Bolic and Zarko Sivcev, professors at Venice International University, set out four areas of improvement. They recommended that research set thresholds to identify the conditions as hazardous, costly or minor. The Icelandic event also raises the question whether volcanic ash is an airworthiness or an air traffic management issue. They also recommend use of measurement devices, such as dropsondes, Lidar, unmanned aircraft and aircraft equipped with measuring devices. To improve communications, they say the move to move to digitalize Notams and meteorological information be accelerated, and that a one-stop shop should be established as a central information bank.

The International Volcanic Ash Task Force established after the ash cloud event by the International Civil Aviation Organization is scheduled to report this May.