Bertie, I'm not too good at explaining this. It isn't the angle of
banking that matters but how fast you roll the airplane on its axis to
to get to the back angle that matters. We've gone thru the arguement
that one can rotate an airplane around its roll axis 360 degrees and
not have someone on that axis feel anything but 1 G into the seat.
This is different -- someone else ran the numbers to show what happens
to the local G sense as a function of how fast the airplane
accelerated into the roll -- we'd have called that alpha with two dots
above it back in the long hand calculus days. Accelerate into the bank
angle too quickly and if I was sitting far from the roll axis you'd
lift the wine from my glass. You would, I promise, need a locked
cockpit door if you did that.

I'd be at whining over spilt wine.

OK, put the stun gun away, or aim it over there at the other widebody
and frequent poster here.



On Oct 19, 2:58 pm, Bertie the Bunyip wrote:
Tina wrote groups.com:

Bertie, the issue isn't the degree of bank, but rather how fast you
roll the airplane into the bank, that would make a px well off center
feel the gs Dave mentioned. For example, if you had Mx sitting on a
wing tip and you wanted to drop the wing out from under him, you'd
bank into that wing quickly. If you banked slowly he'd not feel
himself grow lighter, but if you did it sharply you near the center
line wouldn't feel much but you could yank that tip down at better
than 1 G even when going to a bank limit of 20 degrees. That was the
issue Dave addressed.

The question was, when you start to bank into a turn, how quickly do
you establish the bank angle? I'm guessing you go from wings level to
20 degrees in a slow count of 3 or 4 -- not too much acceleration --
but would appreciate a guesstimate from some who does it for a living.

Well, even in a conventional airplane you try to do it as smoothly as
you can Actually, you try to do that in any kind of flying no matter how
outwardly frantic it may appear! But I can't see it being significant to
pax comfort unless they were out at the wingtips. In any case the
aircraft would almost certainly be fly by wire anyway so the
opportunities we'd have to raise your red wine out of your glass!

Given a cabin width of fifty feet and a rate of rotation of, say, ten
degrees a second, you'd be moving, you'd move about four or five feet in
a second. You'd hardly feel it at all if the rate was introduced
smoothly.
In fact, you'd be closer to the CG than you would be if you sat in the
nose or tail of any other modern jet whilst it was making a pitch
change.

Bertie