Release #05.012
April 29, 2005

Pilots: Urgent Need for Volcanic Ash Monitoring

WASHINGTON, D.C.--- A U.S. Geological Survey (USGS) report released today is the "latest evidence of the growing threat volcanic ash poses to aviation, and underscores the urgent need to fully fund the National Volcano Early Warning System," according to Capt. Terry McVenes, Executive Air Safety Chairman of the Air Line Pilots Association, Int'l (ALPA).

The USGS report, "Framework for a National Volcano Early Warning System" (, was released at a Capitol Hill briefing that included Capt. Ed Miller, leader of ALPA's Volcanic Ash and Aviation Safety Program, among the presenters. The report highlights U.S. volcanoes that are currently under-monitored and pose a serious threat to aviation, including Mts. Pagan, Agrigan, Alamagan, Guguan, Asuncion in the Mariana Islands; Mts. Vsevldof and Kiska in Alaska; Mono Craters in California; Crater Lake in Oregon; and Glacier Peak in Washington.

"You wouldn't sail rough seas without a life preserver," said Capt. Miller. "We shouldn't ignore volcanoes that we know are dangerously under-monitored."

Of particular concern to ALPA are the active volcanoes in the Marianas Islands, a U.S. territory located in the North Pacific Ocean, which USGS reports pose a significant threat to aviation. Only two of the volcanoes have some ground-based, real-time monitoring, and six have no ground-based monitoring at all. The Marianas fall in the path of many U.S. flights bound for Hong Kong and Manila.

"One flight crosses over the Marianas Islands roughly every 22 minutes," said Capt. Miller. "With so much at risk, the USGS needs to be equipped to conduct full monitoring of the Marianas volcanoes to protect the thousands of travelers flying across the Pacific."

"The five-minute warning that pilots received during the Mount St. Helens eruption in 2004 proved that the USGS system works," continued Capt. McVenes. "That's the kind of warning system pilots need for every volcano, and it can only happen through the USGS monitoring program."

Volcanic ash--small, hard particles that may stay aloft for weeks--poses a significant safety hazard to jet airplanes. When the ash first enters the jet engine, the hardness of the volcanic material causes excessive wear on the turbine blades. In the hot section of the engine, the ash melts and adheres to moving parts, causing high temperatures, power loss and stall or flame out.

Volcanic ash is also known to have damaged aircraft windshields so extensively that pilots have not been able to see through the opaque sections. Moreover, volcanic ash has caused loss of airspeed indication and prevented radio communications due to the high level of static electricity generated by the volcanic ash.

"The North Pacific averages five or six eruptions each year, with volcanic ash falling close enough to flight routes to become an aviation safety concern on as many as 12 days a year," continued Capt. Miller.

Between 1980 and 2004, more than 100 jet aircraft sustained damage after flying through volcanic ash clouds. The repairs cost more than $250 million. At least seven of the encounters resulted in temporary engine failure, with three aircraft losing power from all engines. Fortunately, pilots were able to restart enough engines to land safely. The engine failures occurred at distances ranging from 150 to 600 miles from the erupting volcanoes, and aircraft damage from volcanic ash encounters has been reported from as far as 1,800 miles from the volcano.

With the growing number of passengers choosing to travel by air, and the increasing number and density of flights passing near active volcanoes, ALPA strongly advocates the following to protect passengers, crew and cargo:

Click here for a fact sheet on "Volcanic Ash Hazards to Airliners."

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ALPA CONTACTS: John Mazor, Linda Shotwell, (703) 481-4440,