ASW 20 SPIN CHARACTERISTICS

I have been considering buying an ASW20, ASW20B, or ASW20C. I knew
they were champions in their day and still have a lot of admirers.
However a few folks from my club say they have some nasty spin
characteristics. Specifically, that they have a tendancy to not only
immediately spin when stalled, but will go inverted as they spin. Can
anyone eloborate or corroborate? I normally only hear good things
about the 20.
Respectfully,

Ventus B wrote:
I have been considering buying an ASW20, ASW20B, or ASW20C. I knew
they were champions in their day and still have a lot of admirers.
However a few folks from my club say they have some nasty spin
characteristics. Specifically, that they have a tendancy to not only
immediately spin when stalled, but will go inverted as they spin. Can
anyone eloborate or corroborate? I normally only hear good things
about the 20.

I owned a 20B, and it was once of the nicest handling and benign gliders
that I've owned. It would spin, but it would take some abuse, even with
the CG near the aft limit. The 20C apparently has similar handling
characteristics. Some (but not all) of the earlier 20 (aka 20A) ships
are reputedly somewhat less forgiving. Get too slow, and they will
stall and spin rather promptly, with very little warning. I've never
experienced going inverted in a spin, but they will do over the top spin
entries (outside wing drops, and the glider rolls inverted before
settling into a normal spin), which confuses those who haven't
experienced them before.

In any case, the 20B (best for strong conditions) and 20C are preferred,
as they have automatic elevator hookups, tilt-up instrument panels, and
better cockpit ventilation. If you've flown a flapped glider (like a
Ventus B), you'll have no problems with them. If you want to buy an
original 20, talk to some of the past owners, if you can, to get an
assessment of that particular ships quirks.

Marc

One additional observation - depending on exactly when in the
auto-rotation/pitch oscillation cycle the recovery inputs take affect, it
can feel like the ship is going inverted. In other words, it feels like the
nose swings down past vertical before back pressure is applied to recover
once the rotation is arrested. I flew a friend's 20C several times and
tested a bunch of spins from different entry modes, and this was the only
slightly uncomfortable moment. In this case, the ship was equipped with
winglets and the CG was only at about 50 aft CG limit. Not sure whether
this is typical for this combination of ship/configuration.


"Marc Ramsey" wrote in message
m...
Ventus B wrote:
I have been considering buying an ASW20, ASW20B, or ASW20C. I knew
they were champions in their day and still have a lot of admirers.
However a few folks from my club say they have some nasty spin
characteristics. Specifically, that they have a tendancy to not only
immediately spin when stalled, but will go inverted as they spin. Can
anyone eloborate or corroborate? I normally only hear good things
about the 20.

I owned a 20B, and it was once of the nicest handling and benign gliders
that I've owned. It would spin, but it would take some abuse, even with
the CG near the aft limit. The 20C apparently has similar handling
characteristics. Some (but not all) of the earlier 20 (aka 20A) ships
are reputedly somewhat less forgiving. Get too slow, and they will
stall and spin rather promptly, with very little warning. I've never
experienced going inverted in a spin, but they will do over the top spin
entries (outside wing drops, and the glider rolls inverted before
settling into a normal spin), which confuses those who haven't
experienced them before.

In any case, the 20B (best for strong conditions) and 20C are preferred,
as they have automatic elevator hookups, tilt-up instrument panels, and
better cockpit ventilation. If you've flown a flapped glider (like a
Ventus B), you'll have no problems with them. If you want to buy an
original 20, talk to some of the past owners, if you can, to get an
assessment of that particular ships quirks.

Marc

On Mon, 05 Jul 2004 01:45:52 GMT, Marc Ramsey
wrote:

Ventus B wrote:
I have been considering buying an ASW20, ASW20B, or ASW20C. I knew
they were champions in their day and still have a lot of admirers.
However a few folks from my club say they have some nasty spin
characteristics. Specifically, that they have a tendancy to not only
immediately spin when stalled, but will go inverted as they spin. Can
anyone eloborate or corroborate? I normally only hear good things
about the 20.

Some (but not all) of the earlier 20 (aka 20A) ships
are reputedly somewhat less forgiving. Get too slow, and they will
stall and spin rather promptly, with very little warning. I've never
experienced going inverted in a spin, but they will do over the top spin
entries (outside wing drops, and the glider rolls inverted before
settling into a normal spin), which confuses those who haven't
experienced them before.

I'll second that. I have an early '20 (s/n 34) and it does indeed
depart with little warning if I get too slow in a 45+ degree bank (45
kts in zero flap and a gust will do it) but both times I've got it
back within a 1/4 turn and not much height loss. One departure
happened when I gradually tightened the turn past 45 degrees while
keeping the speed to a constant 45 kts, so I guess that's expected
with hindsight. The second was in a more turbulent thermal, so may
have been helped along by a gust.

It does drop a wing when stalled (any flap setting) but that's pretty
benign and not hard to deal with. I would not describe that as a spin
from stall, though it might develop into one if left alone. Standard
spin recovery is: (a) centralise controls, (b) flaps negative, (c)
take normal spin recovery action. So far (c) has not been necessary as
it usually self recovers when the flaps are pushed negative.

I've not yet seen a departure which went past a 90 degree bank.

Other habits:

- trimmed hands off at 50 kts and with feet on to keep straight, mine
has a 25 second phugoid with a +/- 5 kt speed excursion. I let it run
for 5-6 cycles but the amount of the speed excursion seemed stable
after the first couple of cycles.

- trimmed hands and feet off at 50 kts is stable. If the wheel is
dropped or the brakes opened a spiral dive develops - there seems to
be no benign spiral.

I'm very pleased with mine and glad I bought it. It thermals well, is
nicely balanced to fly and has an excellent turn of speed in the
cruise. The learning curve for the flapped life is steep but worth the
effort - its taken me 37 hours over 36 flights (almost all off the
winch) to feel as if I'm up to speed with the flaps but I felt at home
in the glider almost from the start. Mind you, I did have over 150
hours in a Pegase, which I really rate, first!.

FWIW I had 226 solo hours (271 total) when I made my first flight in
the '20 and would not have wanted to tackle it a year earlier (134
hours solo, 174 total) though at that time I would have been happy to
fly almost any 15m standard class glider.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

I have 400 hours in an ASW19 and it does just just about the same,
thermalling slow then getting a gust and a little bit of up stick she would
roll 180 degrees to the high wing to almost an inverted position then
gravity would bring the nose down and start spin entry but recover
instantly the stick goes forward.
The ASW20 is almost identical except having to slide the flaps negative
for the speed your doing and I have flown other types that do exactly the
same, eg: Ventus A/B are aggressive in the entry as well
Overall the I rate ASW20 is one of the best at low speed handling and low
level
thermalling.
Just take the glider up high and explore the limits of the behavior so you
know
the point to which you can take her.
If it really concerns you then get winglets fitted ,best price I found was
from M & H
in the US $1100-$1600 (model dependent) plus fitting, that lowers the
stall speed and noticably changes behavior at slow speed,
improves the L/D as well ))
gary

"Ventus B" wrote in message
om...
I have been considering buying an ASW20, ASW20B, or ASW20C. I knew
they were champions in their day and still have a lot of admirers.
However a few folks from my club say they have some nasty spin
characteristics. Specifically, that they have a tendancy to not only
immediately spin when stalled, but will go inverted as they spin. Can
anyone eloborate or corroborate? I normally only hear good things
about the 20.
Respectfully,

I have flown an early C model with aft c/g (but still in the legal range),
and spin entry was very rapid, with little warning. Back in that time, there
have been 3 fatalities in one year in Germany (1985 or 1986?) with a C
model.

I now fly a A model with Lindner winglets, and I tried stalling/spinning in
all flap configurations. It does sin, but it really needs to be convinced
and can be easily stopped by the standard procedure.

--
Bert Willing

ASW20 "TW"


"goneill" a écrit dans le message de
...
I have 400 hours in an ASW19 and it does just just about the same,
thermalling slow then getting a gust and a little bit of up stick she
would
roll 180 degrees to the high wing to almost an inverted position then
gravity would bring the nose down and start spin entry but recover
instantly the stick goes forward.
The ASW20 is almost identical except having to slide the flaps negative
for the speed your doing and I have flown other types that do exactly the
same, eg: Ventus A/B are aggressive in the entry as well
Overall the I rate ASW20 is one of the best at low speed handling and low
level
thermalling.
Just take the glider up high and explore the limits of the behavior so you
know
the point to which you can take her.
If it really concerns you then get winglets fitted ,best price I found was
from M & H
in the US $1100-$1600 (model dependent) plus fitting, that lowers the
stall speed and noticably changes behavior at slow speed,
improves the L/D as well ))
gary

"Ventus B" wrote in message
om...
I have been considering buying an ASW20, ASW20B, or ASW20C. I knew
they were champions in their day and still have a lot of admirers.
However a few folks from my club say they have some nasty spin
characteristics. Specifically, that they have a tendancy to not only
immediately spin when stalled, but will go inverted as they spin. Can
anyone eloborate or corroborate? I normally only hear good things
about the 20.
Respectfully,

On Tue, 6 Jul 2004 09:39:50 +0200, "Bert Willing"
wrote:

I have flown an early C model with aft c/g (but still in the legal range),
and spin entry was very rapid, with little warning. Back in that time, there
have been 3 fatalities in one year in Germany (1985 or 1986?) with a C
model.

I now fly a A model with Lindner winglets, and I tried stalling/spinning in
all flap configurations. It does sin, but it really needs to be convinced
and can be easily stopped by the standard procedure.

I'd like to add that the 20 of my club with aft C/G also had a rather
violent spin entry at flap setting 4 (thermalling setting), but
overall the spin behaviour of the 20 is very predictable and not
critical at all. I'd deal our 27 for a 20 any time.

The 24 without winglets has a very similar spin behaviour with an aft
CG, btw.


Bye
Andreas

Although George Thelen doesn't name the sailplane that is the subject of his
July 2004 Safety Corner column in Soaring magazine, he seems to be talking
about the ASW 20A. Perhaps someone familiar with that particular accident
could elaborate.



Bryan




"Ventus B" wrote in message
om...
I have been considering buying an ASW20, ASW20B, or ASW20C. I knew
they were champions in their day and still have a lot of admirers.
However a few folks from my club say they have some nasty spin
characteristics. Specifically, that they have a tendancy to not only
immediately spin when stalled, but will go inverted as they spin. Can
anyone eloborate or corroborate? I normally only hear good things
about the 20.
Respectfully,

When I got my first 20A, I was nervous as hell about the spin characteristics
as there had been a whole bunch of spin accidents, world wide. For the first 50
hours I tried to gently provoke her, but she wouldn't depart unless severely
manhandled. After that I settled down and enjoyed the bird. Nothing will climb
like a 20A and those floppy wings, smooth out the ride.
After 10 years or so, I formed the opinion that some 20's would spin at the
drop of a hat and others wouldn't. A friend had a *good* 20, that wouldn't spin
under normal conditions. One day he adjusted the flaps, so that the flaps and
ailerons were all exactly at neutral with the flap handle in zero and the stick
exactly in the middle. You guessed it, after that he had a *bad* 20 that would
spin at the drop of a hat. It could have something to do with the flap
adjustment, but I'm not sure what, because they are flap-erons and move with
the ailerons.
BTW, the accident at Air Sailing was a 20A.
JJ Sinclair

"JJ Sinclair" wrote in message
...
When I got my first 20A, I was nervous as hell about the spin
characteristics
as there had been a whole bunch of spin accidents, world wide. For the
first 50
hours I tried to gently provoke her, but she wouldn't depart unless
severely
manhandled. After that I settled down and enjoyed the bird. Nothing will
climb
like a 20A and those floppy wings, smooth out the ride.
After 10 years or so, I formed the opinion that some 20's would spin at
the
drop of a hat and others wouldn't. A friend had a *good* 20, that wouldn't
spin
under normal conditions. One day he adjusted the flaps, so that the flaps
and
ailerons were all exactly at neutral with the flap handle in zero and the
stick
exactly in the middle. You guessed it, after that he had a *bad* 20 that
would
spin at the drop of a hat. It could have something to do with the flap
adjustment, but I'm not sure what, because they are flap-erons and move
with
the ailerons.
BTW, the accident at Air Sailing was a 20A.
JJ Sinclair

JJ,
Interesting, do you remember what the factory flap setting should be?
On first thought I would think the aileron would be slightly more negative
to the flap setting with the flap handle in neutral. Only when in the high
speed setting would both flap and aileron line up.
Just a thought.
Udo