A Perilous Passage through Volcanic Ash
Monastersky, R., Science News
A perilous passage through volcanic ash
Despite a new warning system designed to prevent such encounters, several planes last week made potentially disastrous trips through ash from an erupting Alaskan volcano. The incidents leave many wondering what went wrong.
In the most serious event, a Boeing 747 operated by KLM Royal Dutch Airlines lost power in all four engines on Dec. 15 when it flew through an ash cloud at 37,000 feet about 75 miles northwest of Anchorage. The plane plunged more than 13,000 feet before pilots restarted its engines, says Ivy Moore of the Federal Aviation Administration (FAA) in Anchorage.
The incident occurred the day after FAA issued its first of several airline advisories concerning the hazards from several eruptions of the Redoubt volcano, says FAA's Richard Stafford in Washington, D.C. The advisories are part of a volcano watch system set up early this year, which uses satellite information to spot ash clouds and notifies airlines about the danger. Redoubt provided the system's first real test.
"The information was out there. The advisories and the warnings were out there. I'm just curious why the plane went into the ash cloud," says Michael Matson, who helped design the system at the National Oceanic and Atmospheric Administration (NOAA) in Washington, D. …