Colin,

I'm just trying to reconstruct the thought process in my
head that could lead someone to take off in these conditions.

Good, that's what I am trying to get people to do.

The reasons are many, but they all fall into the same category: trying
to please somebody. Often its financial pressure (I need the revenue
today); time pressure (we gotta get to work by 8am); social pressures
(they'll think I'm a wimp); need to prove one's self (I'll show them, I
can fly in conditions the rest of these weaklings are afraid of), etc.

Ron Brown is dead because his USAF pilot succumbed to the time
pressure.
JFK Jr is dead because he felt he needed to prove he could do it by
himself.

At the end of Oct we just lost another bizjet in San Diego because they
were in too much of a hurry to take the time to make a phone call and
prefile; instead they did a night VFR takeoff under a 2100 ft overcast,
in a valley surrounded by mountains. The idea was to file in the air
by radio. Their airplane made a big boom and a great flash of light as
it dashed itslef into a zillion pieces against the side of Otay
mountain, 8 nm east of the departure airport. The wreckage was about
3000 feet away from the site where another jet pilot did *exactly* the
same thing, from the same airport, hitting the same mountain, ten years
earlier. In that case it was carrying half of Reba MacEntyre's band.

I'm sure they saved at least 10 to 15 minutes each.

Recommended reading: AC60-22, available online at the faa's website.
Redefining Airmanship, by Tony Kern. Aviation Psychology, ed by
Roscoe. Human Factors in Aviation, ed by Nagel.

"If you think you are late now, just imagine how late you will be when
you are dead."

Gene