Are 'Single 180 Turn From Downwind to Final' and 'Stall-spin on Turnfrom Base to Final' mutually exclusive?

On 11/23/2016 12:50 AM, Tango Whisky wrote:
Bob,

you've stated that you haven't flown an ASW20C, but still you comment on
its flying characteristics, citing a 2-32 as reference?!

What a nonsense.

I have flown an ASW20C (15 m, no winglets, CoG towards the rear limit), and
there is no warning _what so ever_.

Bert

Snip (of all but the offending post, immediately below)...

Blame this somewhat-thread-drifting post on winter finally trying to put
in an appearance in this part of the northern hemisphere...

I'm guessing what Eric's "no warning" comment means is "in the absence of
a distinct separation-induced burble," or something similar (I've not
flown either an ASW 20 or ASH 26). I'm gonna "winter-quibble" with the
concept "no warning."

My club used to have a 2-32 (eventually sold) about which the same thing
was routinely said, and in fact the ship did routinely and
enthusiastically drop the same wing before beginning a rapid rotation if
not "immediately and properly countered." If it really did catch someone
out, going through at least 90-degrees of an incipient spin, and WAY nose
down before recovery - was in your immediate future. Many club pilots of
roughly equivalent time as I then had might accurately have been
described as "unduly frightened" of the ship.

But "no warning?" Surely you jest (and my name isn't Shirley). True,
before the wing "let go" there was (almost always) an absence of
aerodynamic burble felt through the stick or one's butt or merely
"drummed" through the metal fuselage, but by the time the wing did let
go, "all the other usual suspects" had put in their appearances: low wind
noise; nose noticeably high; controls (especially stick) getting sloppy;
etc. Subsequent to checking out in the ship, I found it "intellectual
fun" to mess around with it in slow flight "trying to find the burble."
Abrupt departure from controlled flight - yes, indeed! "No warning?" -
not by a long shot.

Bob - a big fan of coordination AND "sufficient airspeed" - W.


Bert - I'm also a big fan of, "If it happens, it must be possible."

As you likely grasped, I sought not to comment upon the ASW 20C's specific
low-speed, essentially-1g, departure from controlled flight characteristics,
as on the *concept* of departing from controlled flight "in the general
vicinity of" those flight conditions...which is why I included the
experience-based provisos leading into the guts of my post.

FWIW, I've yet to encounter a glider or single-engine general aviation
airplane that has not provided *some* other clue(s) Joe PIC is in the vicinity
of the sandbox near an unintended departure from controlled flight. (N.B. I'm
also not power certified, my experience in powered planes being limited to
riding along in lots of different types, with lots of different pilots, doing
"the usual range of stuff" from stall practice to "straight-n-level" hard IFR.
Nor do I have any supersonic aircraft time. )

As always when discussing any aeronautical topic having even the slightest
hint of nuance, YMMV.

Bob W.

P.S. Apologies if some form of this post appears twice; the first attempt
seemed to have disappeared into the bit bucket without trace, despite an hour
of searching...

Bob, I've flown about 40 different types of gliders, and did voluntary spins with about half of them, wingspans ranging from 10 m to 26 m.

And the ASW20C was stunning in this respect - pulling from cruise into thermal a bit sharply, and the sky turns green although the glider just felt perfectly normal. In Germany in the mid-eighties, this behaviour did kill a couple of ASW20C pilots. Moving the CoG forward changes the behaviour to "normal".
The only other glider I came across having this behaviour was a Fox - but then, this one is designed to do exactly that.

So, there ARE gliders out there that bite without barking first.

On Wed, 23 Nov 2016 08:36:45 -0800 (PST), Tango Whisky
wrote:

Bob, I've flown about 40 different types of gliders, and did voluntary spins with about half of them, wingspans ranging from 10 m to 26 m.

And the ASW20C was stunning in this respect - pulling from cruise into thermal a bit sharply, and the sky turns green although the glider just felt perfectly normal. In Germany in the mid-eighties, this behaviour did kill a couple of ASW20C pilots. Moving the CoG forward changes the behaviour to "normal".
The only other glider I came across having this behaviour was a Fox - but then, this one is designed to do exactly that.

So, there ARE gliders out there that bite without barking first.


Hi Bert,

the ASW-20 is a nice example of how little airfoil differences can
make huge differences.

I've flown two different ASW-20's.

The first was a 20L with slightly modiefied leading edge radius.
Performance-wise it was probably the best ASW-20 ever, and, stalled
with flaps 4, it had that sudden departure into a spin that you
descibe.

The other one was an ASW-20C. As docile as it gets - it was even
possible to thermal it with flaps 4 and less than 80 kp/h without the
slightest sign of a stall, not to mention that it didn't even drop a
wing if stalled.
CG a little bit more forward than in the 20L, though. This pilot got
heavier over the years.


And then there are those open class ships. I was quite surprised how
smoothly the Nimbus 3D went into a spin when I was checking out its
low-speed thermalling manners...



Viele Gruesse aus der Pfalz
Andreas