Mark James Boyd
August 27th 03, 06:42 PM
>http://home.quicknet.nl/qn/prive/f.braaksma/
>
>or as my coworker said "don't do this to your daddy's 737".
OK, so good opportunity for me to discuss hail...
So the FAA books recommend flying at least 20NM away from isolated
thunderstorms, under the concept, I assume, that hail sucked
way up into the flight levels (40-50 thousand feet or higher)
can be blown by 200+ knot winds aloft and fall 20NM away.
This means it takes about 6 minutes for the hail to fall from
FL600 (OK, just guessing here).
But it seems VERY clear that this is not random. If the
wind is blowing from the West or South consistently at
all altitudes, then if you fly West and South of that
particular thunderstorm, its hail will not be in your path.
So the key to avoiding hail seems to be knowing the path
the hail will take at the altitudes where it exits the
cumulonimbus.
This isn't idle wondering. I'm making a flight tonight from
WVI to Burning Man - Black Rock City near Reno, CA. There's
a 20% chance of isolated thunderstorms, and I'm working
on a course to best avoid the possibility of flying
170+ kts through hail. There's clearly a better and worse
way to do this, and flying "upwind" of isolated CB seems
to be better. Note that I mean "upwind" in the sense
of the wind where the hail is, not upwind at my chosen
flight altitude...
>
>or as my coworker said "don't do this to your daddy's 737".
OK, so good opportunity for me to discuss hail...
So the FAA books recommend flying at least 20NM away from isolated
thunderstorms, under the concept, I assume, that hail sucked
way up into the flight levels (40-50 thousand feet or higher)
can be blown by 200+ knot winds aloft and fall 20NM away.
This means it takes about 6 minutes for the hail to fall from
FL600 (OK, just guessing here).
But it seems VERY clear that this is not random. If the
wind is blowing from the West or South consistently at
all altitudes, then if you fly West and South of that
particular thunderstorm, its hail will not be in your path.
So the key to avoiding hail seems to be knowing the path
the hail will take at the altitudes where it exits the
cumulonimbus.
This isn't idle wondering. I'm making a flight tonight from
WVI to Burning Man - Black Rock City near Reno, CA. There's
a 20% chance of isolated thunderstorms, and I'm working
on a course to best avoid the possibility of flying
170+ kts through hail. There's clearly a better and worse
way to do this, and flying "upwind" of isolated CB seems
to be better. Note that I mean "upwind" in the sense
of the wind where the hail is, not upwind at my chosen
flight altitude...