10-26-2007, 06:00 PM
re volcanic ash:
USGS says:
"Ash ingested by jet engines may lead to the immediate deterioration in engine performance and engine failure. The principal cause of engine failure is the deposition of ash in the hot sections of the engine. Glass from melting volcanic ash will coat fuel nozzles, the combustor, and turbine, which reduces the efficiency of fuel mixing and restricts air passing through the engine. This causes surging, flame out, and immediate loss of engine thrust. Ash may also seriously erode moving engine parts, including the compressor and turbine blades, which reduces the efficiency of the engine."
Volcanic ash can cause all engines of a jetliner to lose power in less than a minute. It's not a matter of corrosion over time.
This page from the havo site:
"Do Hawaiian eruptions pose a threat to aircraft?"
http://hvo.wr.usgs.gov/volcanowatch/2004/04_08_26.html
explains that volcanic ash comes from "explosive" eruptions, which Kilauea has had in the past but in not currently, then goes on to explain about "effusive eruptions,"
"In terms of everyday operations, explosive Hawaiian eruptions pose infrequent but significant threats to aircraft. Effusive eruptions, which are much more frequent in Hawai'i, also produce airborne particles, but to much lower densities than explosive eruptions.
The only incident of aircraft problems due to Hawaiian eruptions was the crash of a Bell 206 helicopter in November 1992 in the crater of Pu'u '?'?. The helicopter, which was carrying a film crew from Paramount Pictures, flew through the volcanic gas plume.
The plume is known to be highly corrosive and low in oxygen, and the helicopter's engine failed as a result of ingesting volcanic gas.
The threats posed to aircraft by effusive eruptions are just a severe as those posed by explosive eruptions, but only for the area immediately around the vent or vents."
Edited by - KathyH on 10/26/2007 22:09:15
USGS says:
"Ash ingested by jet engines may lead to the immediate deterioration in engine performance and engine failure. The principal cause of engine failure is the deposition of ash in the hot sections of the engine. Glass from melting volcanic ash will coat fuel nozzles, the combustor, and turbine, which reduces the efficiency of fuel mixing and restricts air passing through the engine. This causes surging, flame out, and immediate loss of engine thrust. Ash may also seriously erode moving engine parts, including the compressor and turbine blades, which reduces the efficiency of the engine."
Volcanic ash can cause all engines of a jetliner to lose power in less than a minute. It's not a matter of corrosion over time.
This page from the havo site:
"Do Hawaiian eruptions pose a threat to aircraft?"
http://hvo.wr.usgs.gov/volcanowatch/2004/04_08_26.html
explains that volcanic ash comes from "explosive" eruptions, which Kilauea has had in the past but in not currently, then goes on to explain about "effusive eruptions,"
"In terms of everyday operations, explosive Hawaiian eruptions pose infrequent but significant threats to aircraft. Effusive eruptions, which are much more frequent in Hawai'i, also produce airborne particles, but to much lower densities than explosive eruptions.
The only incident of aircraft problems due to Hawaiian eruptions was the crash of a Bell 206 helicopter in November 1992 in the crater of Pu'u '?'?. The helicopter, which was carrying a film crew from Paramount Pictures, flew through the volcanic gas plume.
The plume is known to be highly corrosive and low in oxygen, and the helicopter's engine failed as a result of ingesting volcanic gas.
The threats posed to aircraft by effusive eruptions are just a severe as those posed by explosive eruptions, but only for the area immediately around the vent or vents."
Edited by - KathyH on 10/26/2007 22:09:15