Has anybody bothered to study similarities between this eruption and Mt. St-Helens in 1980 in N. America? I remember my car, in Eastern Canada, having a fine ash coating at the time. I don't recall any massive airspace closures nor aircraft falling out of the sky at the time (which was when I was doing my PPL); however Google isn't turning much up on the subject. I do recall that eruption produced massive quantities of ash.