This volcano affected several flights in 1997 and 1998. Although
damage was minor in most cases, one flight crew experienced significantly
reduced visibility for landing and had to look through the flight
deck side windows to taxi after landing. In addition, the airport
in Mexico City was closed for up to 24 hr on several occasions during
subsequent intermittent eruptions.
RESOURCES AVAILABLE TO HELP AVOID ASH ENCOUNTERS
Although some information about volcanic eruptions has been available
for many years, the aviation industry and volcanological community
began a joint effort to find ways to avoid future encounters after
the Mt. Redoubt eruption. At an international conference in Seattle,
Washington, in July 1991, aviation industry members, meteorologists,
and volcano scientists gathered to determine what volcano event
information the aviation industry needed, how this information could
be distributed, and who or which agencies should distribute it.
The International Civil Aviation Organization (ICAO) had laid much
of the foundation for the volcanic ash issue through its Volcanic
Ash Warnings Study Group; see “ICAO
Activities on Volcanic Ash.”
of the outcomes of this initial meeting is the availability of today’s
Volcanic Ash Advisory Centers (VAAC). The VAACs provide an important
link among volcano observatories, meteorological agencies, air traffic
control centers, and operators. A total of nine VAACs observe and
report on a particular region of the world (fig.