May 5, 2010

Statement of Victoria Cox, Senior Vice-President for NextGen and Operations Planning

Before the U.S. House of Representatives Committee on Science and Technology, Subcommittee on Space and Aeronautics on Mitigating the Impact of Volcanic Ash Clouds on Aviation – What Do We Need To Know?


Chairwoman Giffords, Ranking Member Olson, Members of the Subcommittee:

Thank you for inviting me to testify before you today on mitigating the impact of volcanic ash clouds on aviation. The Federal Aviation Administration (FAA) has dealt with the issue of volcanic ash clouds before, both from a research and an operational perspective, and we are happy to share this information with this Subcommittee.

Effects of Volcanic Ash on Aircraft

Volcanic ash is extremely damaging to aircraft. Should an aircraft encounter volcanic ash during flight, it could ingest the ash into the engines. If the volcanic ash passes through the turbine engines of an aircraft, the burner section can melt the ash, which then can deposit on the turbine’s nozzles as a hard glaze. This can negatively affect the engine’s operation and can result in a loss of power or total shutdown of the engine. When an engine loses power or shuts down due to turbine nozzle glazing, it will cool down rapidly. This can result in the fracturing of the volcanic ash glaze. Once the glazing breaks up and falls away, the engine may be able to resume normal operation.

There are additional negative effects of volcanic ash on an aircraft turbine engine. These may include erosion of compressor blades and rotor-path components as well as turbine cooling passages, contamination of the oil system and bleed air system, and plugging of the engine’s inlet pitot static probes. These effects can cause severe and costly damage to an aircraft and its components.

FAA Volcanic Ash Response

While the severe impact of a major volcanic event such as we saw in Europe last month is extremely unusual, volcanic eruptions are not unusual. There is almost always an eruption somewhere in the world that may pose a concern to international air navigation. In certain parts of the United States, such as Alaska, volcanic eruptions are enough of a possibility that the FAA has developed an operational response.

FAA Orders 7900.5B and 7110.65T and JO 7930.2M Notice to Airmen (NOTAM) provide operational information regarding volcanic ash. The FAA’s primary method of dealing with volcanic ash events is operator avoidance. Since the geographical location of areas that may be affected by volcanic ash is weather-dependent, our model of managing air traffic when confronted with volcanic ash is to treat it much like a major weather event. That is, we gather the information from the reporting agencies and disseminate that information to the operators of aircraft. In turn, the operator makes the decision to fly or not. If the operator chooses to fly, then our air traffic controllers will direct the operator around the volcanic ash to the best of our abilities.

As an additional safety precaution, on April 22, 2010, the FAA issued a Special Airworthiness Information Bulletin, NE-10-28, regarding turbine engine operation in volcanic ash airspace. The FAA noted that before flying from the United States to Europe or within Europe, aircraft owners and operators should review the following recommendations:

  • Although the FAA does not recommend engine operation or flight into a visible volcanic ash cloud, we do recommend that aircraft owners and operators obtain definitive information on operational limitations around ash clouds, if any, from each of the European National Authority of the State(s), over which they plan flight operations.
  • Follow all aircraft and engine manufacturer’s operating and maintenance instructions pertaining to operations in airspace where volcanic ash may be near or present.
  • Report any inadvertent encounter with volcanic ash or relevant findings, including abnormal engine behavior, to the respective type certificate holders of the aircraft and engines.

FAA Past Volcanic Ash Research Efforts

In the 1990s, the International Civil Aviation Organization (ICAO) established Volcanic Ash Advisory Centers (VAAC) that disseminate information worldwide on atmospheric volcanic ash clouds that may endanger aviation. There are nine VAACs located around the world run by local weather forecasting organizations. In the United States, the National Oceanic and Atmospheric Administration (NOAA) runs VAACs in Anchorage, Alaska and Washington, D.C.

In the past, the FAA has participated with other federal agencies on developing a national plan for dealing with volcanic ash with regard to aviation operations. Under the auspices of the Office of the Federal Coordinator for Meteorological Services and Supporting Research (OFCM), led by NOAA, the FAA helped develop the National Volcanic Ash Operations Plan for Aviation.

Because the FAA is essentially a consumer of weather services, we work with the weather-reporting agencies to develop weather products specifically for aviation use. Our role in that partnership is to set the requirements of what the weather products must provide in order to be useful for aviation users, whether they are air traffic controllers or pilots. Accordingly, our participation in the OFCM project was primarily to set the requirements for the development of volcanic ash information products for the FAA and aviation operators to use.

Aviation operations in volcanic ash situations rely on information based on detection and monitoring, alerting, modeling, and post event assessments. The U.S. Geological Survey (USGS) provides seismic monitoring for early detection and passes the information directly to the FAA to provide early warnings when an eruption is imminent or has occurred, which is especially important for en route aircraft. NOAA uses satellite monitoring as a core element in detection, tracking, and monitoring eruptions, and the resultant ash plume. Pilots also make observations, and the FAA disseminates pilot reports or PIREPS along with NOTAMs and Significant Meteorological Information (SIGMETs). SIGMETS originate from NOAA’s National Weather Service.

Much of the capability to predict dispersion of volcanic ash clouds is based on mathematical modeling.The HY-SPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) model is the current model in use by NOAA and Australia's Bureau of Meteorology and its Darwin VAAC. Other, similar, models are used by other VAACs. Post assessment is carried out by the USGS, NOAA and the Smithsonian to determine how we can improve the services provided to industry and the FAA’s air traffic management.

FAA Assistance in Response to Eyjafjallajokull Eruption

The European response to last month’s volcanic eruption in Iceland was generally to close the airspace where volcanic ash could pose a threat to aviation safety. This was due in part to the constrained airspace over Europe and the need to coordinate the actions of the multiple civil aviation authorities of the various countries of the European Commission.

After the shutdown of airspace, European regulators were faced with the challenge of reopening their airspace, and the FAA was able to lend its expertise to our counterparts in Europe. FAA air traffic personnel also participated in a daily telephone conference with the United Kingdom’s Civil Aviation Authority and the inter-disciplinary group they assembled. While we primarily offered information on our operator avoidance practices, we also helped to brainstorm operational solutions for reopening European airspace such as developing a collaborative volcanic ash forecasting process and developing “pathfinder” test flight traffic patterns between cities with a low ash impact.

NextGen and Volcanic Ash

I know that this Committee is interested in how the Next Generation Air Transportation System (NextGen) may affect our current model of operator avoidance when confronted with volcanic ash. Because the issue is really based upon receiving the best information, NextGen will enable an improved information sharing process. NextGen focuses on how to best put information in a format that can be used by pilots, controllers, and dispatchers and integrated into decision support tools.

Volcanic ash information is treated like significant weather information. Under NextGen, the NextGen Network Enabled Weather (NNEW) product will enable the publication of the same weather information to all airspace users. NOAA’s role will be to provide quality data to all its users including data that meets the FAA’s air traffic control requirements. The FAA will integrate the information provided by NOAA into tools expressly for air traffic management. NextGen will help improve the quality and delivery of information to the FAA and aviation users, enabling all of us to make better informed operational decisions when confronted with adverse conditions such as volcanic ash.

Madame Chairwoman, Ranking Member Olson, Members of the Subcommittee, this concludes my prepared remarks. Thank you again for inviting me here today to discuss the impact of volcanic ash on aviation operations. I would be happy to answer any questions that you may have.

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