ASW 20 Handling Issues?

[ank...@comcast.net]

The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?

Tom A

[Tango Whisky]

I used to fly an ASW20C (15 m, no winglets) with an aft CoG, and it would spin without any warning. Mowing the CoG forward removed this behavior.
Lateron I owned an ASW20 (A-model with winglets) wich I flew with a 1/3 aft position, and it was completely harmless.

Bert TW

[Martin Gregorie]

I had an early ASW-20 (s/n 34), the so-called A series, with the two
stage landing flap. Twice it departed in a thermal turn without any
warning, zero flap (position 3) 40-45 degree bank, flying at 45 kts. Both
times It recovered after a 1/4 turn, though 300 ft lower and now at 80
kts. The second time it happened I tried to reproduce the same behaviour
after arriving back home in late afternoon with plenty of height in hand,
but was unable to get it to spin similar from turns at the same or a
slightly lower airspeed. I was forced to conclude that this was either
idiosyncratic behaviour of my particular ASW-20 or it had something to do
with micro-turbulence in the thermal.

Apart from that I had no issues with its handling once I'd learnt to fly
a flapped glider properly and not to add 5 kts to approach speed for luck
since that made it want to float into the next county after rounding out.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[uncl...@ix.netcom.com]

On Sunday, November 5, 2017 at 1:55:40 AM UTC-4, ank...@comcast.net wrote:
> The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?
>
> Tom A

The '20 got a poor early reputation due to it's spin characteristics when flown with aft CG. When it came out it was very common for pilots to fly with far aft CG to try to get more performance.
I have extensive experience in A and C versions. Something around 1200 hrs or so. When flown at, or aft of the manufacturer's aft CG point they both depart and spin quite quickly. A pilot can be easily surprised by this.
That characteristic does not surface, from my experience, with the CG forward of the 80% point. It will still spin, but doesn't snap the same way. Flown well behind manufacturer's limit, is, in my opinion, very dangerous.
There is negligible performance lost at 75-80% and interestingly enough, the trimmer isn't even needed. I flew my 20C with the trimmer taped off the entire time I owned it.
I also found that external seals, in addition to the usual internal seals, seems to make the tendency to drop a wing at high angles of attack less. I'm pretty sure this is due to spanwise flow in the trailing edge cove that gets trapped by the seals.
Winglets, again from my experience, make the stall and wing drop more docile, but make the spin, as it develops, more abrupt.
There is a reason these ships have remained popular and desirable.
FWIW
UH

[Andreas Maurer]

On Sat, 4 Nov 2017 22:55:39 -0700 (PDT), ank...@comcast.net wrote:

>The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?

I've got extensive experience in the ASW-20L and a little in an
ASW-20C.

My club's 20L was ok before it got a refinishing which resultetd in a
slioghtly sharper leading edge of the wing (and significantly
increased performance).
Before the refinishing, it would slightly drop a wing but that wasn't
worse than in any other glider of that time. After that, it could
enter a spin if stalled in flaps 4 and a slightly aft CG if you didn't
catch the dropping wing immediately.

Not visious, but it needed a little attention.

On the other hand, I've also flown a privately owned ASW-20C that was
extremely harmless and could be thermalled at less than 80 kp/h
without the slightest tendency to drop a wing.

In my opinion the flight characteristics of the ASW-20 are mostly
definied by the form of the leading edge of the wing and reports about
bad reputation are grossly overblown. In the 600 hrs I have on the 20
I had no a single unexpected departure.

My club operated the ASW-20L for 15 years where any pilot with more
than 100 hrs total flight time could fly it, and to my knowledge there
was never a serious spin incident. We sold it accident-free.

Disclaimer:
Of the 60+ different glider types I have flown so far, to me the 20
still has best flying characteristics.

[tow...@gmail.com]

On Saturday, November 4, 2017 at 10:55:40 PM UTC-7, ank...@comcast.net wrote:
> The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?
>
> Tom A

Thanks for all the responses; very helpful.
Tom A

[WB]

On Sunday, November 5, 2017 at 12:55:40 AM UTC-5, ank...@comcast.net wrote:
> The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?
>
> Tom A

Second what the others have said about spins with the CG too far back. I have 20a serial #18. With full thermalling flap (actually hardly ever needed). Mine will drop a wing upon stall. Just a normal wing drop that can be countered with forward stick and a bit of opposite rudder. Essentially identical behavior to my 301 Libelle with full positive flap. So, nothing abnormal for early high performance gliders.

After slipping my 301 to landings for the last 20 years, I love the 20's glide path control. Full landing flaps and full divebrakes make for parachute steep landings. However, landing flaps on the 20a can lead to trouble for the incautious. One has to be absolutely sure of having the landing site made, especially in full landing flap. Not advisable to move the landing flap handle once established on short final. Coming out of full flap will cause the glider to drop in hard, or worse, lead to a stall/spin if one pulls back to try to stop the fall.

[chip.b...@gmail.com]

Interesting thoughts about a glider that has been around--and much loved--since the late 1970s. I have less than 10 hours in two ASW 20s (a very early one and a later A) so I can't speak from experience. When it began to develop a bit of a reputation back in the 1980s, I heard a story/rumor/speculation that the fabric tape used to cover the flap/wing joint might be to blame if it bulged out into the airflow during slow flight and triggered separation. No idea if that was true but subsequent models used Mylar seals (and/or beryllium copper for at least one ASW 20B) and I suspect most early models have been fitted with Mylar. If I were buying a '20, I'd look at the seals--and CG--closely just to be careful.

Chip Bearden

[Dave Nadler]

On Sunday, November 5, 2017 at 2:23:24 PM UTC-5, chip.b...@gmail.com wrote:
> ...I heard a story/rumor/speculation that the fabric tape used to cover

> the flap/wing joint might be to blame if it bulged out into the airflow
> during slow flight and triggered separation.

IIRC that tape bulging caused aileron flutter, but not other problems.
Regardless, the tape should have been replaced with mylar on all 20's.
Hank???

[uncl...@ix.netcom.com]

Flutter was associated with seal tapes. Flaps fluttered more than ailerons if I remember correctly. Mylar is a good improvement and was standard on B and C. Flaps on A go down far enough to be tough on Mylar on bottom when in full landing flap.
UH

[johnsin...@yahoo.com]

A few 20's were produced with slightly different incidence angles in the wings..........yep, the wings were not hooked on straight! I'm sure those ships liked to spin when flown too slow. Schleicher had several "eccentric" rear lift fittings to solve the problem. I'd bet they are all fixed by now, but if your 20 always seems to turn one way, your wings may not be true!
JJ

[krasw]

On Sunday, 5 November 2017 23:45:19 UTC+2, uncl...@ix.netcom.com wrote:?

>
> Flutter was associated with seal tapes. Flaps fluttered more than ailerons if I remember correctly.

> UH

Mine had aileron vibration (it is not flutter) twice with pristine teflon/mylar seals, so it might not be that simple. I did change flap hinge bearings and new seals just to be sure and never experienced vibration again. (Control play was well within limits before change).

Talking about 20 handling, you would probably compare it to gliders similar vintage. LS4, Discus or Ventus with aft c/g will spin as eagerly and drop wing in most cases in similar fashion. 20 is no different in that respect. I flew 20 for over 1000hrs with few wing drops after mishandling the glider in thermal but I wouldn't call the glider anything but extremely well-behaved. It is the safest glider to land in tight spot. One of few gliders that truly were well ahead of it's time.

[kochan...@gmail.com]

On Sunday, November 5, 2017 at 1:55:40 AM UTC-4, ank...@comcast.net wrote:

> The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?
>
> Tom A

600+ hours in a 20B ... one instant over the top spin in a strong small-core thermal ... I did have an extreme aft CG (I had a tail tank with a separate dump control from the wings.) Did some stall testing when I first transitioned to the 20 and thought the transition was pretty normal - although not as benign as the LS-3 which was my prior ship. I then installed elevator tabulators and verified they provided a lot of additional control into the stall. Your experience may differ. kk

[chip.b...@gmail.com]

On Sunday, November 5, 2017 at 10:28:45 PM UTC-5, johnsin...@yahoo.com wrote:
> A few 20's were produced with slightly different incidence angles in the wings..........yep, the wings were not hooked on straight! I'm sure those ships liked to spin when flown too slow. Schleicher had several "eccentric" rear lift fittings to solve the problem. I'd bet they are all fixed by now, but if your 20 always seems to turn one way, your wings may not be true!
> JJ

Errata:

Interesting. I recall that a few ASW 19s had the same problem...and solution: i.e., eccentric rear lift pins from the factory. My memory might be playing tricks but the guy who told me about it had a '19, not a '20. I've always wondered how the wing was twisted after that since the spars and main pins weren't altered. :)

My memory might be playing tricks, Part II, but regarding flap flutter, I also recall hearing that some early '20s had a slight amount of "slop" in the flap drive that was fixed by smearing epoxy on the end of a long wooden stick or dowel, jamming it into the wing root at the appropriate point, waiting for it to harden up, then breaking off the stick/dowel. Apparently a bunch of owners had theirs done on a rain day at a big contest (late 70s/early 80s?). That seemed to address the flap flutter.

I believe Rudy Mozer's ASW 20B was one of four brought over for the Worlds (Hobbs, 1983). When I saw it that spring, it had lower flap seals that were beryllium copper (to accommodate the landing flap deflection?). Pretty nifty looking. Beryllium copper dust is toxic so that might have killed any enthusiasm for using this material.

Chip Bearden

[JS]

Krasw, I've been thinking the same.
This was a period of pushing performance without as much consideration for things like handling, cockpit ergonomics and safety as there is in current models. Seems there was always something missing. Perhaps Gerhard did better with general handling than Klaus achieved in the Ventus A/B, but the Ventus had auto hook ups while the early 20s required connecting 7 L'Hotelliers. The elevator became auto hook up in late 20B and all C model, or modification using Tech Note 29.
Rick Wagner had some mods for 20s that improved performance, including shortening of the flap at the root and aileron at the tip, a better wing root fairing, and a wingtip that looked like an LS4. His work was before we had winglets.
Sorry that the earliest Ventus I've flown was the C, which had lovely handling. The A/B without winglets seemed to have a reputation for needing to be flown all the time. The 20 A- B- and C- models I've flown all had great handling (pilot-glider relationship much like any other Schleicher) and personally didn't have any spin entry threat. One of them was a "Hobbs Special", but the high red line was only for the duration of the Worlds. None had winglets, which seem to improve characteristics near to stall speed.
I've been on both sides of this equation: ASW20 flying alongside ASW27. In the midrange there was no difference! One mistake in a 20 and you won't catch up, though.
The LS6 was the easiest to fly well of this vintage in my experience. Climbs full of ballast and outruns a 20. Not enough time alongside Ventus A/B or C at 15m. Once ran all day at Ely with a 15m V2 at the same wing loading.
Once swapped an original LS6B for one with the Flying Nun tips for a few days. Thought the biggest difference was in blocked visibility.
Jim

[krasw]

On Monday, 6 November 2017 19:44:45 UTC+2, JS wrote:
> I've been on both sides of this equation: ASW20 flying alongside ASW27. In the midrange there was no difference!

27 is overrated, that tiny wing needs 18m span to work as intended as 29 has shown. I've flown 20 against 27 and sure it runs a little better at very high speeds but you can basically fly all day long side by side and arrive home 5 minutes later. When you put glider price into that equation...

[David Salmon]

At 05:55 05 November 2017, ank...@comcast.net wrote:
>The ASW 20 seems to have a reputation for bad behavior in some

>configuratio=

>ns. Is this reputation deserved or overblown? What has been the

>experienc=

>e of those who have owned and flown the glider? Are some variants of the

>2=

>0 better or worse in terms of handling characteristics?
>
>Tom A
>

I can only claim about 400 hours in a 20, and almost invariably flew it at
16.6m, and it never showed any untoward handling characteristics. I have
read, though never experienced it, that they can depart easily when in
landing configuration.
Dave

[Mike the Strike]

I owned WA - Wally Scott's ASW20 for a number of years. It was a while before I discovered he had secreted large amounts of lead in the wings and tail and that the W&B data was completely fictitious. I can confirm that with a CG well aft of the factory permitted range it can depart into a spin quickly and viciously!

With the lead removed and the CG returned to the permitted range, I never experienced another problem. There were reports of a tendency to spin when the "Jesus" landing flap position of early ASW20s was selected, but this again was not a problem I encountered.

Mike

[WB]

I think the departures that occur in the "Jesus" landing flap position result from pilots realizing too late that they are coming up short and getting too slow in an attempt to make the landing area. My advice to new 20a drivers: If you are going to use full landing flap, don't aim for the near end. Choose a touchdown point in the middle of your chosen landing area!

[chip.b...@gmail.com]

Anyone purchasing an ASW 20A (actually, ANY glider), should query the previous owner (and assess his/her weight--hopefully without insulting them!), inspect the logbook and placards, and then do a full weight and balance to check the CG before flying it.

Recognizing that this latter time-consuming step may not be done by everyone immediately, at a minimum, inspect the tail for lead weights. In more recent gliders, there's often a battery compartment at the top of the vertical fin. The lead in my ASW 24 lives below the battery there so inspect carefully.

In older gliders, lead was added by removing the rudder and bolting it in the lower fin area. I removed the lead I had installed in my LS 3 when I sold it even though the new owner weighed more than I did. There's a lo-o-o-o-o-ng moment arm all the way back there so a small amount of weight has a fairly significant effect on the CG. It may be difficult or impossible to inspect for this without removing the rudder. Also, weight may have been added to the tailwheel or (in one case I'm aware of) in the tailwheel area itself

Obviously the CG can also be too far forward. I've seen lead weights in the nose installed by lighter pilots. But the too-far-aft CG seems to be more common and insidious.

The rule for CG is: take nothing for granted, even from the factory. I recently spoke with a very careful, highly analytical friend who discovered--after an alarming first flight--that the minimum cockpit weight for his new glider was far higher with the longer wingtips installed than with the short tips.

Taking your CG for granted can be fatal. I am familiar with at least one such stall/spin crash where CG may have been a factor.

Chip Bearden

[urban...@gmail.com]

On Saturday, November 4, 2017 at 11:55:40 PM UTC-6, ank...@comcast.net wrote:
> The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?
>
> Tom A

You may have hit the nail when you posted "Some Configurations". Don't put in full landing flaps on an early 20 until you are on final and have the field made. You will be rewarded with the ability to land anywhere. With full flaps it is like flaring a hang glider. Do a weight and balance before you fly if you suspect any undocumented lead in the tail. Using Gerhard's CG recommendation mine stalled and flew like a trainer. I flew a friends 20 and the handling was like balancing on a pin so rigging may be an issue on some of these older ships.
Also, The notion that the 27 is "overrated" is silly. If you get a chance, fly them both and you will go with the 27.

[ND]

When i bought my 20c i was instructed by HW to not pull landing flaps until after turning final, both because the stall departure is more sudden and severe, and because you have to be high as hell on base to need landing flaps already.

Obviously in an A model this is even more prounounced.

as far as spinning in flight, we've got ours at 80%, and i have had it break into a spin entry a time or two, but only when i was really muscling the glider around in a thermal. normally it totally behaves. i wouldn't call it any worse than another glider. if you're at the aft limit though, obviously all bets are off...

[ND]

i did fly a 27, and i kinda was unimpressed in the difference. having flown against 27's in the past, i can also say that on the east coast a 20 can hang, unless the 27 pilot is s**t hot. i wouldn't pay 3x for a better role rate, and a few more L/D. if the 20 had automatic hookups like a 27, i'd never upgrade. i will say that from a cockpit comfort perspective, the 20 and 27 just work better with my body. i can sit in my 20 for 6 hours and feel great. if i fly a discus or a V2 for that long, my lower back and the back of my knees start hurting. but they are both excellent machines too. the ventussbx was the most beautifully handling glider i've ever flown.

[Tango Whisky]

Le mercredi 8 novembre 2017 14:38:12 UTC+1, ND a écrit :
> On Tuesday, November 7, 2017 at 4:38:03 PM UTC-5, urban...@gmail.com wrote:
> > On Saturday, November 4, 2017 at 11:55:40 PM UTC-6, ank...@comcast.net wrote:
> > > The ASW 20 seems to have a reputation for bad behavior in some configurations. Is this reputation deserved or overblown? What has been the experience of those who have owned and flown the glider? Are some variants of the 20 better or worse in terms of handling characteristics?
> > >
> > > Tom A
> >
> > You may have hit the nail when you posted "Some Configurations". Don't put in full landing flaps on an early 20 until you are on final and have the field made. You will be rewarded with the ability to land anywhere. With full flaps it is like flaring a hang glider. Do a weight and balance before you fly if you suspect any undocumented lead in the tail. Using Gerhard's CG recommendation mine stalled and flew like a trainer. I flew a friends 20 and the handling was like balancing on a pin so rigging may be an issue on some of these older ships.
> > Also, The notion that the 27 is "overrated" is silly. If you get a chance, fly them both and you will go with the 27.
>
> i did fly a 27, and i kinda was unimpressed in the difference. having flown against 27's in the past, i can also say that on the east coast a 20 can hang, unless the 27 pilot is s**t hot.

That may hold with an ASW20 and and ASW27 both empty.
If conditions are good and the 27 loads up to almost 50 kg/m2, a 20 dowesn't stand a chance.

[ND]

i did specify east coast. ;) maybe i should have been more clear. northeast. we don't fly with water most of the time.

[jfitch]

Never flown a 20 or 27 (can't fit in them) but flown numerous very long final glides (50+ miles) against numerous examples of both. This is in the west usually with water. There is a huge difference between them. After 50 miles or so the 27 will be a few hundred feet below my 18m, the 20 will be a few thousand.

[Charlie M. (UH & 002 owner/pilot)]

20 A/C or 20 B?
A 20 B full of ballast goes pretty good in strong conditions (ridge or thermal), I believe the other 20's are "maxed" at 9LBS.

I have flown a 20 C on the Mifflin ridges (central Pennsylvania for those that don't know, home of some great eastern US ridge flying and many records) against Ventus and LS6 at full weight in regionals and Nationals.
Knowing the area and where gaps were, I could gain, then get run over on longer runs due to wing loading.

In terms of flying any 20, pretty nice ship if you mind CG. Flown with and without winglets.
Yes, 20 A at full landing flaps and dive brakes, you go down like a "homesick brick". Every spring, after a few flights, I would arrive on final waaaaay too high, then "hang it all out" and drop like a stone just to get used to the decent rate.


I flew a 20 C with the CG behind the aft limit ONCE by accident (multiple pilots on a single day, I was the lightweight at about 150LBS, decided to fly with more aft CG, didn't know previous 250 pounder did the same......I didn't count lead discs in the nose.......my bad).
A few aggressive thermal "yank, crank and bank" were met with over the top spin entries at altitude.
Owner saw one (while towing) and asked if I was practicing spin recoveries. Well, yes I was, but that was not the intent.

I have to say, all the "AS" gliders I have flown are fairly easy to get into, even for modest time pilots. Get a good briefing, have some time under your belt, practice some more extreme flying as you gain time.

The earlier comment about getting time in a Cessna 150 and trying full flaps, great idea. I went from "SGS" trainers/low performance to 1-35, PIK-20 and one other in quick succession after a few flights in a 150 where I was shown the relationship of flaps and pitch.

A 20 (having divebrakes) can be easier to transition to compared to "flap only" like a 1-35/PIK/etc. For local flying, set thermal flaps, then fly divebrakes until you get the feel.

So, is a 20 a "spin machine"? No, if being mindful of CG. The 80% of CG is likely fine for most flying. A bit further back may gain a tiny bit of performance but spins become more noticeable.

[George Haeh]

My 20 was well behaved, but if you have the $$$, go for a 27.

+

Much easier for us older folk to rig
Automatic Hookups
More margin in limit airspeeds

-

Smaller O2 bottle courtesy automatic hookups
Carbon fiber fuselage incompatible with internal transponder or flarm
antenna

When buying a single seater, be extra cautious if the seller is heavier
than you. I
took several lead plates above the tailskid out of the 20 after doing a W&B
and
calculating where I wanted the CG. At 80% my 20 was well behaved.

If you happen to get bit by a 25+ kt gust, you may discover some unusual
attitudes that you can't reproduce in better behaved air.

[badelit...@gmail.com]

Op zondag 5 november 2017 06:55:40 UTC+1 schreef ank...@comcast.net:

[youngbl...@gmail.com]

I flew the ASW20 for about 1500 hours, it is the finest 15 meter ship ever built at the time. Mine was fantastic, it was a L model, wold run like a scalded ape and no bad habits that you could not recognize. Bob

[Dave Nadler]

On Tuesday, December 19, 2017 at 5:55:46 PM UTC-5, youngbl...@gmail.com wrote:
> ... no bad habits that you could not recognize.

OK, what were the bad habits you could recognize???

[youngbl...@gmail.com]

Meant to say there were no bad habits!!! Fantastic ship, would go down in the sailplane hall of fame if it existed. Bob