On 3/5/2014 2:53 PM, John Carlyle wrote:
Agree with your three points of how pilots get into trouble. I also agree
that training is important, and that it's never a bad idea to take a ride
with an instructor.

I'm not sure I buy your theory of an optical illusion in your peripheral
vision causing your central vision and inner ear to start giving you bad
data, though. It takes time (probably a minute) without good visual cues
for your inner ear to start disconnecting from reality.

Apologies for the thread drift, but my experience strongly suggests the
"probably a minute" for inner ear to disconnect from reality is "probably
(way?) too long."

I once inadvertently entered an utterly benign (no overdevelopment anywhere
that day) thermal cloud by horribly misjudging the base in conjunction with a
honking climb rate. In the dry intermountain west, racing another guy half a
mile away over the plains of eastern Colorado, it went from CAVU VFR to
solidly-opaque IFR more or less instantly. Flying in a
large-deflection-landing-flap-equipped sailplane (no spoilers) thousands of
feet agl in the middle of nowhere, I wasn't worried about pulling my wings
off, but I *was* distinctly irked at my poor judgment, mostly because if I
didn't fly out the side of the cloud quickly, my buddy would gain considerably
on me. (Standard glider pilot priorities!)

I'd at least had the sense to establish my climb near the far edge of the
miles-long cloud, had a long-established bank angle/turn-rate, and figured I'd
a good chance of rolling out on a heading to have me clear of the cloud within
no more than 5-10 seconds at the most. Without moving my head, once inside the
solidly opaque cloud, and not touching the controls until estimating it was
time to roll out, I did so, timing/estimating wings level, and waited. The
only thing that happened "instantly" was violent vertigo, and within 15
seconds several things were clear: 1) I wasn't going to exit the side of the
cloud; 2) I'd stalled at least once (at which point I pulled on full flaps);
and 3) it was anyone's guess how long I'd be in the cloud and what my flight
path might be while there. Ultimately, I lost 700 feet from my max altitude
before exiting the thing, out the bottom, steeply banked the opposite
direction from that entered, and never knowingly having commanded bank after
the attempt to unbank to level. My buddy was nowhere in sight, of course.

Point being, don't bet your life on having much time IFR before losing
complete control of your glider. Secondary point being (of course!) don't go
IFR at all, but if you DO go IFR be prepared to lose your wings and maybe your
life unless your glider has gobs of disposable drag...as has had every
landing-flap-equipped sailplane I've flown. Wonderful things, large deflection
flaps!

Bob - occasionally bozo - W.