Flying through volcano ash?

  1. lisab

    Staff: Mentor

    This isn't purely an Earth science question, but I don't know where else to post it. Recently, the Kasatochi volcano erupted in Alaska. It brought to mind something that happened to me a long time ago that I have always wondered about.

    In 1989 I was flying from Alaska to Seattle. Days earlier, Mt Redoubt - a volcano in the Aleutian chain - had a big eruption. Most flights out of Anchorage were cancelled but I was surprised that my flight was scheduled to go.

    Just minutes into the flight, the cabin was filled with airborne ash. It was so thick that it bothered everyone's eyes and if you ground your teeth together, you could feel the grit. I recall a slight sulfur smell.

    It only lasted maybe 10 seconds. The flight went on without incident.

    I always wondered were ever really in danger? What's the protocol for flying through a volcano plume?
     
  2. jcsd
  3. wolram

    wolram 3,778
    Gold Member

    No way should you fly through volcanic ash, there was a famous incident where an aircraft lost all engine power and had to glide for miles.
     
  4. lisab

    Staff: Mentor

    Yes, I figured it wasn't safe. It was actually terrifying. Can't a plume be seen on radar?
     
  5. Evo

    Staff: Mentor

    Wow, that is very scary Lisab. I wonder why the pilot would take such a risk.
     
  6. wolram

    wolram 3,778
    Gold Member

  7. Were you flying KLM, Lisa?

    Check:

    http://www.alpa.org/DesktopModules/...View.aspx?itemid=1470&ModuleId=1316&Tabid=256

     
  8. lisab

    Staff: Mentor

  9. LURCH

    LURCH 2,514
    Science Advisor

    Didn't look at the link yet, but does it say anything about the ash getting inside the passenger compartment? I would think that in a pressurised cabin, the quality of the outside air could not effect people's eyes or cause grit in their teeth. Maybe what you all experienced was ash from the recent eruption that got into the cabin while the plane was on the ground, and ti settled into the ventilation system, only to get blown back out into the cabin when the system was turned on. You say it atsrted just minutes into the flight, maybe that's the time it took to get out of the vents and into your face.
     
  10. lisab

    Staff: Mentor

    Hmmm...I guess that makes sense! It was odd to me, too, how it got into the cabin. I suppose it may have been in the ventillation system somehow.
     
  11. Astronuc

    Staff: Mentor

    I believe commercial airliners take some of the air from the engine compressors, and that's why one will smell the fuel odor in the cabin when the doors are closed and the engines are started. The compressors obviously suck in the local air. Similarly in an ash cloud, the dust would find its way into the cabin.

    Ash would certainly be detrimental to the compressor and turbine blades, and mess with the fuel/air mixing in the combustors, as well as accumulate in the hot areas of the engine.

    http://volcanoes.usgs.gov/Hazards/Effects/Ash+Aircraft.html
     
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