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As I understand it the major risk is that because the ash cloud is very dry radar won't pick it up at all. So you could fly 1000 planes and miss the cloud by l

• gaius 17y ago
  BA at least say that satellite images show the cloud as smaller than the Met Office's computer model predicted it would be. Airspace was closed on the say of the latter. Note that the Met Office's models have been way off since at least last winter...
  • ErrantX 17y ago
    NASA satellite images this morning match the Met Office model pretty closely.
    • gaius 17y ago
      But do they match what the model said 5 days ago it would look like in 5 days time?
• hugh3 17y ago
  Given the worst-case scenario of a failure of all engines and nothing else at cruising altitude over Europe, and assuming you have a skilled pilot, what's the probability of gliding in for a safe landing? I'd think pretty high, since anywhere in Europe should be within safe gliding distance of a reasonable-sized airport. There are stories of landing safely under much worse conditions (eg the Gimli Glider which landed with no hydraulics or electronics and that US Airways flight into the Hudson which landed despite losing engines at low altitude).
  • lutorm 17y ago
    There are at least as many stories of not landing safely, not only killing the people onboard but also on the ground. Europe is quite densely populated. And I don't think you're within gliding distance of an airport at all, especially since they fly lower than normal to avoid the ash, and even if they are, I'm not sure what the odds of a successful dead-stick landing is. Given that most pilots have probably never tried it, I'd bet the odds of stalling out short of the runway or overrunning at high speed are pretty large. Ultimately, it's a matter of weighting risk, and given that there seems to be no accurate assessment in combination with the shitstorm that would arise if they allowed flights to resume and a plane went down, I can't blame the authorities.
    • sanj 17y ago
      Poweroff landings are part of all flight training, even for a simple flight license. Any commercial pilot can handle it adroitly.
      • lutorm 17y ago
        It is for single-engine licenses, I'm not entirely sure that they are for multi engine jets. Given the likelihood of an all-engine out, I'm not sure that's practiced much. They also don't practice ditching on water, for example. (And let me clarify that I'm not saying they couldn't set it down, I'm sure they can do that. I'm saying that it's not clear to me that you can easily manage energy so you end up at the end of the runway in a position to touch down at the right speed.)
    • hugh3 17y ago
      Looking up the Gimli Glider it seems that they had a 12:1 glide ratio, so if your engines fail at 35,000 feet that should give you a range of about 128 km. I'm not sure whether it's possible, without leaving Europe, to get more than 128 km from the nearest airstrip capable of landing at least a small airliner. Difficulties: if they're flying low to avoid the ash. Also, not all of Europe is at sea level, so if you're flying at 35,000 feet over the Alps then you might only be 25,000 feet above ground.
  • modoc 17y ago
    I think that's overly-optimisitc and only covers intra-European flights, not trans-Atlantic flights.