For those flying Pacific North Routes.
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Eight Gun Fighter
Joined: Apr 2000
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From: Western Approaches
For those flying Pacific North Routes.
Mount Redoubt volcano in the US state of Alaska has erupted for the sixth time in 24 hours, spewing ash and steam 15km (9.3 miles) into the air.
The volcano, 166km (103 miles) south-west of the state's biggest city, Anchorage, began erupting late on Sunday after a 20-year lull.
Ash has risen as high as 50,000 feet
Ash has fallen on towns north of Anchorage, but the city itself has not been affected by the eruption.
Alaskan Airlines has cancelled a number of flights because of the ash.
Officials at the Alaska Volcano Observatory were able to monitor the latest eruption live via a webcam.
"We were able to see mudflows, pyroclastic flows and a nice ash column shooting out of the summit," geologist Janet Schaefer told the BBC. "It was quite spectacular."
Ms Schaefer said the ash, which can cause skin irritation and breathing problems, was so far not too dangerous for people living in the vicinity but was dangerous for air traffic.
People living in the path of ash cloud have taken precautions
The ash can cause damage to jet engines. People with respiratory problems have been warned to stay indoors until the ash settles or to wear a face mask if they go outside.
Ms Schaefer said the Observatory was working with the Federal Aviation Administration (FAA) and the National Weather Service to track ash clouds and ensure flights were diverted or cancelled if necessary.
Dozens of aircraft at the Elmendorf Air Force Base in Anchorage were being sheltered as a precaution against the falling ash.
Mount Redoubt, which stands 3,100m (10,200ft) high, last erupted over a four-month period from 1989 to 1990.
Scientists monitoring the area warned in late January that an eruption was likely.
On Sunday, officials raised the alert level after researchers recorded increased seismic activity.
"If it is anything like the 1989 eruption, we could expect activity to continue for three to four months," Ms Schaefer said.
bbc
The volcano, 166km (103 miles) south-west of the state's biggest city, Anchorage, began erupting late on Sunday after a 20-year lull.
Ash has risen as high as 50,000 feet
Ash has fallen on towns north of Anchorage, but the city itself has not been affected by the eruption.
Alaskan Airlines has cancelled a number of flights because of the ash.
Officials at the Alaska Volcano Observatory were able to monitor the latest eruption live via a webcam.
"We were able to see mudflows, pyroclastic flows and a nice ash column shooting out of the summit," geologist Janet Schaefer told the BBC. "It was quite spectacular."
Ms Schaefer said the ash, which can cause skin irritation and breathing problems, was so far not too dangerous for people living in the vicinity but was dangerous for air traffic.
People living in the path of ash cloud have taken precautions
The ash can cause damage to jet engines. People with respiratory problems have been warned to stay indoors until the ash settles or to wear a face mask if they go outside.
Ms Schaefer said the Observatory was working with the Federal Aviation Administration (FAA) and the National Weather Service to track ash clouds and ensure flights were diverted or cancelled if necessary.
Dozens of aircraft at the Elmendorf Air Force Base in Anchorage were being sheltered as a precaution against the falling ash.
Mount Redoubt, which stands 3,100m (10,200ft) high, last erupted over a four-month period from 1989 to 1990.
Scientists monitoring the area warned in late January that an eruption was likely.
On Sunday, officials raised the alert level after researchers recorded increased seismic activity.
"If it is anything like the 1989 eruption, we could expect activity to continue for three to four months," Ms Schaefer said.
bbc
Joined: Jan 2007
Posts: 729
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From: San Jose
So what happens to all the US<>Asia flights that might go through the affected area? Do they take more fuel and take a longer route, stop somewhere to top up the tanks (given that I know there are 14hr sectors that must be close to range limits) or just cancel them?
What does it do for your ETOPS if the diversion airport for a particular area is under the ash cloud?
What does it do for your ETOPS if the diversion airport for a particular area is under the ash cloud?
Last edited by llondel; 24th March 2009 at 20:03. Reason: Added ETOPS question
Joined: Nov 2005
Posts: 109
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From: Harvest, Alabama
No doubt all the NoPac routes are being monitored.
At the moment, the jet stream is northbound from the Volcano, so minimal impact on PANC based routes.
The sad part is normal ops there peak at dark of night, so it's tough to do the see-and-avoid in worst case scenario.
At the moment, the jet stream is northbound from the Volcano, so minimal impact on PANC based routes.
The sad part is normal ops there peak at dark of night, so it's tough to do the see-and-avoid in worst case scenario.
Joined: Jun 2001
Posts: 2,627
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From: UTC +8
Flights continue as usual with planned weather diversions. The ash clouds are tracked by meteorologists just as are pacific typhoons or tropical storms which are circumnavigated.
On a northerly trans pacific flight, such as YVR-HKG, a preplanned, overall reroute further south from the Alaskan peninsula, or Aleutian chain, if necessary, would be insignificant. For 4-engined, non ETOPS airplanes, SFO or LAX-HKG routes are far south and wouldn't be affected by Alaska weather. Moreover, prevailing winds generally cause the ash clouds to drift east, and not south unto pacific routes.
On a northerly trans pacific flight, such as YVR-HKG, a preplanned, overall reroute further south from the Alaskan peninsula, or Aleutian chain, if necessary, would be insignificant. For 4-engined, non ETOPS airplanes, SFO or LAX-HKG routes are far south and wouldn't be affected by Alaska weather. Moreover, prevailing winds generally cause the ash clouds to drift east, and not south unto pacific routes.
Joined: Mar 2002
Posts: 4,569
Likes: 1
From: Florida
Those planning on landing in Alaska need to take account of the ash stratification at different altitudes based on wind differences at those altitudes.
By this time the company dispatch and routing procedures should know what routes and altitudes are at risk and advise their flights.
If you don't know than don't go.
If you get caught by surprise (St elmo's fire, acrid smell, etc.) then don't advance the throttles.
By now every cockpit should have SOPs to cover this
By this time the company dispatch and routing procedures should know what routes and altitudes are at risk and advise their flights.
If you don't know than don't go.
If you get caught by surprise (St elmo's fire, acrid smell, etc.) then don't advance the throttles.
By now every cockpit should have SOPs to cover this
Joined: Jun 1999
Posts: 2,997
Likes: 35
From: Oztrailia
SFO or LAX-HKG routes are far south and wouldn't be affected by Alaska weather
I hope they don't this week!!
Lampasso............indeed, the checklist calls for consider a U turn and descend.
