Volcanic Ash Aviation Hazard

The U.S. Geological Survy(USGS) is helping to lead a major international effort to warn the aviation community about the hazards of volcanic ash clouds. Aircraft that encounter volcanic ash clouds have lost engine power. If aircraft have to lower their flying altitudes to stay beneath an ash cloud, airport approaches are affected, and some airports can be forced to shut down. Partners are being sought for two major approaches to this problem; developing new sensors to detect and, ultimately to predict, thepaths of volcanic ash clouds, and to bring educational technologies to pilots, aircraft manufacturers, and others who must be aware of aviation hazards.

In 1989, a wide-body passenger jet destined for Anchorage airport flew into the volcanic ash cloud generated by Mount Redoubt, Alaska and lost thrust all 4 engines. The plane entered the ash cloud at 25,000 feet, accelerated, and then rapidly descended to 13,000 feet. The pilot was finally able to restart its engines. The Alaska Range inthe area where the plane lost powe has peaks from 7,000 to 11,000 feet, so this was an extremely close call. In 1992, the effects of volcanic eruptions on aviation were felt well beyond Alaska when a volcanic ash cloud from the Mount Spurr (Alaska) eruption drifted across the continental U.S. and Canada, shutting down airports in the Midwest and Northeast two days after the eruption. The Spurr cloud affected citizens who are normally not concerned about volcanoes.

Volcanoes are active throughout the rim of the Pacific Ocean, as well as in other locations. Many of these volcanoes are in current flight paths.

Some of the lessons learned from studies of the Alaskan volcanic ash clouds have implications on national and international aviation, particularly:

• Ash clouds may occur during as well as after volcanic eruptions and may affect aviation operations far from the cloud's source.
• Communications between commercial, operational, and scientific personnel are critical in avoiding volcanic hazards.
• It is critical to evaluate the strengths and weaknesses of the current hazard warning system.
• Satellite data provide location and trajectory information, and ultimately vital estimates of particle sizes an concentrations
• Based on these findings, new sensors will be developed which will change the way ash clouds are detected.

Ash clouds commonly look like normal weather clouds and cannot be seen by the weather radar carried in the cockpit. Currently, providing warnings to pilots requires close coordination of information between volcanologists, seismologists, meteorologists, weather forecasters, controllers, dispatchers, and the pilots themselves. The USGS is seeking partners to assist in developing newsensing technology that can be used to detect and predict volcanic ash clouds. Educational materials, such as a computer-assisted training module have been designed and tested. Partners are needed to assist in bringing this training material to the user community and to develop additional training activities.

For More Information

For more information on this CRADA opportunity, contact:

Dennis Krohn
U.S. Geological Survey
927 National Center
Reston, VA 20192
703-648-6371
Fax: 703-648-4828
E-mail: dkrohn@usgs.gov

The USGS welcomes discussions from anyone who would like to explore potential CRADA opportunities. For more information, contact:

U.S. Geological Survey
Technology Transfer Office
104 National Center
Reston, VA 20192
703-648-4450
Fax 703-648-5470
E-mail: tto@www.usgs.gov