Spinning the SZD 50-3

Chris Nicholas wrote:
Shawn Curry wrote "So I'm a test pilot every time I fly from my home
field at 7,500 ft MSL?"

I suspect you may be, if you go in for multi-turns spins at much above
that sort of altitude. That's the point I was asking about. What do
you think?

More conventional high flying is probably within the range of Reynolds
numbers that correspond with tests, provided you don't push the envelope
at the edges. Also the difference in density and RN is not great from
7,000 to 7500 feet.

If you know all this, of course, you can educate me by telling me the
answers.

If you don't - . . . back to your own question, I think, or perhaps an
aerodynamicist could tell us both (and any others who may be
interested).

The higher you go, of course, the more difference it makes. As pointed
out in other threads, if you go high enough, you stall at the same speed
as flutter onset, which leaves no usable envelope at all.

In my earlier post about true velocities/IAS/density/AoA/rotational
speed etc., as I don't know if everyone realises their tie up with
Reynolds numbers, I deliberately didn't refer to RN. Few (certainly not
me) would know off by heart the formulae, even if they have heard of the
things, or how the other factors and RN change with height. I did,
however, presume that all post bronze or equivalent people will have
done some reading on true vs IAS, flight envelopes, etc.. and might
therefore appreciate that the geometry of a spin, effectiveness of
control surfaces, and rotational aspects, high up could be different
from lower down.

My education on the subject has been to the extent that TAS increases
for a given altitude vs IAS and the need to decrease Vne to avoid
flutter at altitude. The notion that RN changes significantly from sea
level to 17,999 feet (where I often fly over Colorado) and that this
changes how the aircraft performes WRT spins, or any other performance
factor is news to me. From reading about the PERLAN project in Soaring
a couple years ago, I new this was significant at 100,000 ft MSL. Maybe
someone else can give more insight into real changes up to the bottom of
Class A.

Shawn