ASW-24

As I recall, the ASW-24 had a climb problem until it
was discovered the ship must be flown a bit faster
while thermaling. Is this true and at what speed do
you thermal the ship?
JJ

At 02:00 26 May 2005, Udo Rumpf wrote:
In fact it is the other way around.
Is the winglets that is the key.
The 'blunting', changing the first 10% of the airfoil
in the outboard
section
of the wing was thought to improve the climb but it
turns out to be a well
designed winglet that made the difference. The factory
winglet did not
perform as well. Those in the know are changing back
to the original airfoil
as
the cruise is improved but climb does not deteriorate.
It was not the airfoil but rather the small Reynolds
numbers in the wing tip
region that caused the problem, which the winglet
corrected.
The 24 is still very competitive indeed.
I do agree with the rest of your comments.
Regards
Udo

wrote in message
roups.com...
Lee,
The ASW-24 is a great aircraft, but I'm sure you have
discovered in
your research that the 24's original airfoil was discovered
to not
perform as well as expected in rough air. There was
a relatively
simple remedy which was to 'blunt' the leading edge.
Before worrying
about the winglets I'd check to ensure that this modification
has been
done.
And to answer your question, if the avionics are top
notch and the
winglets PROPERLY installed and the finish in very
good condition, then
$45k sounds like a fair price in my opinion.
It's a beautiful aircraft.
Respectfully,

Lee Rusconi wrote:
I have an opportunity to buy a 1988 ASW-24 which is
in beautiful condition, good electronics and great
trailer. The glider is equipped with M&H winglets.
The asking price is $45,000 US. I would appreciate
any feedback regarding the winglets and/or the price.

Thanks

J.J.
Since I am a relative late comer to the ASW 24
and have flown it only with the B mod. and Nixon winglet
My target speed "at a 45deg". bank and empty at 7.3lb/sqft
is about 50kt.
Regards
Udo

"John Sinclair" wrote in message
...
As I recall, the ASW-24 had a climb problem until it
was discovered the ship must be flown a bit faster
while thermaling. Is this true and at what speed do
you thermal the ship?
JJ

At 02:00 26 May 2005, Udo Rumpf wrote:
In fact it is the other way around.
Is the winglets that is the key.
The 'blunting', changing the first 10% of the airfoil
in the outboard
section
of the wing was thought to improve the climb but it
turns out to be a well
designed winglet that made the difference. The factory
winglet did not
perform as well. Those in the know are changing back
to the original airfoil
as
the cruise is improved but climb does not deteriorate.
It was not the airfoil but rather the small Reynolds
numbers in the wing tip
region that caused the problem, which the winglet
corrected.
The 24 is still very competitive indeed.
I do agree with the rest of your comments.
Regards
Udo

wrote in message
groups.com...
Lee,
The ASW-24 is a great aircraft, but I'm sure you have
discovered in
your research that the 24's original airfoil was discovered
to not
perform as well as expected in rough air. There was
a relatively
simple remedy which was to 'blunt' the leading edge.
Before worrying
about the winglets I'd check to ensure that this modification
has been
done.
And to answer your question, if the avionics are top
notch and the
winglets PROPERLY installed and the finish in very
good condition, then
$45k sounds like a fair price in my opinion.
It's a beautiful aircraft.
Respectfully,

Lee Rusconi wrote:
I have an opportunity to buy a 1988 ASW-24 which is
in beautiful condition, good electronics and great
trailer. The glider is equipped with M&H winglets.
The asking price is $45,000 US. I would appreciate
any feedback regarding the winglets and/or the price.

Thanks

JJ,

Good winglets fix the climb "problem" (which wasn't much of a
problem--I flew mine sans winglets the first year and loved it). Hank
Nixon and I have a friendly ongoing debate over whether the modified
leading edge (the famous "B" mod) does anything beneficial. He did the
mod; I didn't. I think he's just keen to see me take a file to my
leading edge.

With Hank's latest winglets, my ship climbs with anything. I'd thought
until last year that I had to fly it a little faster; e.g., low 50s
(kts.) in moderate banks. But I discovered at New Castle that in
survival conditions, I could fly it just like a 1-26 and it climbs
great: i.e., slow it down until it's on the edge of buffet.

There may or may not be some benefit to the blunter "B" leading edge in
gusty thermals but I haven't noticed. I do agree with those who believe
that the debate over the airfoil, micro-turbulence, etc., was primarly
a very effective (obviously!) marketing campaign on the factory's part.
After all, how do you sell a brand new glider that doesn't seem to go
any better than the old model unless you can point to something that's
been "fixed"?

Chip Bearden
"JB" ASW-24 owner since 1992

John Sinclair wrote:
As I recall, the ASW-24 had a climb problem until it
was discovered the ship must be flown a bit faster
while thermaling. Is this true and at what speed do
you thermal the ship?
JJ

It's true what you say. The first flights I tried to thermal at 80-85kph,
just as I had done on ASK-21, Astir, and Discus I previusly flew. Found it
harder to climb. I thermal now around 90-95kph and I find no problem. Just
had to be slightly more careful about speed. It climbs very well if you
respect the speed range.

"John Sinclair" escribió en el
mensaje ...
As I recall, the ASW-24 had a climb problem until it
was discovered the ship must be flown a bit faster
while thermaling. Is this true and at what speed do
you thermal the ship?
JJ

Of course it would be true, at 80km/k you would be flying to slow
if you tried to thermal.
This is minimum sink speed in level flight at 6.5 lb/sqft.
at 7.5 lb/sqft you would be approaching stall speed.

To recap the ASW24 does not have to be flown any faster then
other glider of its type. Two gliders you have mentioned have a much
lighter wingloading and the Discus and the ASW24 with 7.5 lb/sqft
will fly at about the same speed.

Now I know how misinformation gets started.

Regards
Udo


"J.A.M." wrote in message
...
It's true what you say. The first flights I tried to thermal at 80-85kph,
just as I had done on ASK-21, Astir, and Discus I previusly flew. Found it
harder to climb. I thermal now around 90-95kph and I find no problem. Just
had to be slightly more careful about speed. It climbs very well if you
respect the speed range.

"John Sinclair" escribis en el
mensaje ...
As I recall, the ASW-24 had a climb problem until it
was discovered the ship must be flown a bit faster
while thermaling. Is this true and at what speed do
you thermal the ship?
JJ

Udo Rumpf wrote:
Of course it would be true, at 80km/k you would be flying to slow
if you tried to thermal.
This is minimum sink speed in level flight at 6.5 lb/sqft.
at 7.5 lb/sqft you would be approaching stall speed.

To recap the ASW24 does not have to be flown any faster then
other glider of its type. Two gliders you have mentioned have a much
lighter wingloading and the Discus and the ASW24 with 7.5 lb/sqft
will fly at about the same speed.

Now I know how misinformation gets started.

Regards
Udo

Udo,

A related question in terms of data points. How significant is the
in-flight CG on climb performance? It's purely subjective, but my LS8
seems to climb markedly better now that I've moved the CG back to about
80% of aft limit (from a previous 45%). Locically, aft CG would
reduce the amount of lift (nose up pitch) required of the
elevator/stabilizer, reducing induced drag from these surfaces. As a
percentage of total induced drag I'm sure this relatively small, but is
it significant?

Erik Mann (P3)

Eric
From my initial set-up I flew with a C of G in the 50% to 55% range.
This worked out nicely. The up elevator in climb was identical
to the down in cruise. I was happy with this compromise.
Then I loaded water 55 litres in each tank about 240 lb total.
To thermal, I needed much more control input and up elevator,
due to the water being ahead of the C of G. Also I had the sense,
aside from being heavier, it was not climbing as well. This could
have been subjective. I added 5 lb to the tail and the handling
improved and felt just as before when dry.
I was surprised when I dumped the water how much more nimble
and responsive but still very comfortable it felt. I am flying dry now
at 85% C of G. The elevator with the new C of G, once the bank and turn
is established, has a minimal up deflection but in cruise the elevator
is even more in a down deflection. This causes more drag. This can
be corrected by placing a washer under the bolt attachment of the
stab to reduce the angle of incidence to reduce the down deflection
in cruise. Ideally the ASW 24 should have a tail tank.
Anyone know of someone that made this mod on the 24?
Regards
Udo



"Papa3" wrote in message
ups.com...


Udo Rumpf wrote:
Of course it would be true, at 80km/k you would be flying to slow
if you tried to thermal.
This is minimum sink speed in level flight at 6.5 lb/sqft.
at 7.5 lb/sqft you would be approaching stall speed.

To recap the ASW24 does not have to be flown any faster then
other glider of its type. Two gliders you have mentioned have a much
lighter wingloading and the Discus and the ASW24 with 7.5 lb/sqft
will fly at about the same speed.

Now I know how misinformation gets started.

Regards
Udo

Udo,

A related question in terms of data points. How significant is the
in-flight CG on climb performance? It's purely subjective, but my LS8
seems to climb markedly better now that I've moved the CG back to about
80% of aft limit (from a previous 45%). Locically, aft CG would
reduce the amount of lift (nose up pitch) required of the
elevator/stabilizer, reducing induced drag from these surfaces. As a
percentage of total induced drag I'm sure this relatively small, but is
it significant?

Erik Mann (P3)

Udo Rumpf wrote:
Eric
The elevator with the new C of G, once the bank and turn
is established, has a minimal up deflection but in cruise the elevator
is even more in a down deflection. This causes more drag. This can
be corrected by placing a washer under the bolt attachment of the
stab to reduce the angle of incidence to reduce the down deflection
in cruise. Ideally the ASW 24 should have a tail tank.
Anyone know of someone that made this mod on the 24?
Regards
Udo


What you really need is a lead weight on a track mounted in the
fuselage driven by a small motor. Move the weight back for climb.
Move it forward for cruise :-)) Actually, the flight research
department at my University had this installed in Navions. I guess
I'm only half-joking...

P3

Papa3 wrote:

Udo Rumpf wrote:

Eric
The elevator with the new C of G, once the bank and turn
is established, has a minimal up deflection but in cruise the elevator
is even more in a down deflection. This causes more drag. This can
be corrected by placing a washer under the bolt attachment of the
stab to reduce the angle of incidence to reduce the down deflection
in cruise. Ideally the ASW 24 should have a tail tank.
Anyone know of someone that made this mod on the 24?
Regards
Udo



What you really need is a lead weight on a track mounted in the
fuselage driven by a small motor. Move the weight back for climb.
Move it forward for cruise :-)) Actually, the flight research
department at my University had this installed in Navions. I guess
I'm only half-joking...

P3

Reminds me of the "mercury pump" gadget Moffat supposedly revealed to
his fellow contestants on the start grid one long-ago day.

Didn't matter whether it worked or not, the other guys were so psyced
out they were beaten before they hooked up.

Bob Johnson

At 19:30 27 May 2005, Bob Johnson wrote:
Papa3 wrote:

Udo Rumpf wrote:

Eric
The elevator with the new C of G, once the bank and
turn
is established, has a minimal up deflection but in
cruise the elevator
is even more in a down deflection. This causes more
drag. This can
be corrected by placing a washer under the bolt attachment
of the
stab to reduce the angle of incidence to reduce the
down deflection
in cruise. Ideally the ASW 24 should have a tail tank.
Anyone know of someone that made this mod on the 24?
Regards
Udo



What you really need is a lead weight on a track mounted
in the
fuselage driven by a small motor. Move the weight
back for climb.
Move it forward for cruise :-)) Actually, the flight
research
department at my University had this installed in
Navions. I guess
I'm only half-joking...

P3

Reminds me of the 'mercury pump' gadget Moffat supposedly
revealed to
his fellow contestants on the start grid one long-ago
day.

Didn't matter whether it worked or not, the other guys
were so psyced
out they were beaten before they hooked up.

Bob Johnson


Moffat comes from a racing sailboat tradition, where
trickery is admired if not the norm and where clever
rule beating devices are constantly developed. I heard
of one sailor who, not allowed ballast at his weighing,
put several boxes of tomato soup (highest specific
gravity) in the bilges as crew provisions.

I never met George and I'm not accusing him of cheating,
but the out-psych'em strategy is certainly a NE tradition.