ASW 20 Handling Issues?

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

On Sunday, 5 November 2017 23:45:19 UTC+2, 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.

On Sunday, November 5, 2017 at 1:55:40 AM UTC-4, 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

At 05:55 05 November 2017, 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

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

On Tuesday, November 7, 2017 at 9:59:38 AM UTC-6, Mike the Strike wrote:
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

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!

On Tuesday, November 7, 2017 at 11:31:34 AM UTC-5, WB wrote:
On Tuesday, November 7, 2017 at 9:59:38 AM UTC-6, Mike the Strike wrote:
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

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!

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...

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

Very true. I took delivery of a new V2C that was supposed to be adjusted for my weight at the factory. Flew without re-weighting glider. First flight was a great soaring day, thank goodness, took about fours to be able to control glider between 45 - 75 knots. Turns out the tail weight was supposed to be 5 pounds, but factory put in 5 KG! Felt like trying to wrestle a greased pig.

On Tuesday, November 7, 2017 at 9:11:55 AM UTC-8, wrote:
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

On Saturday, November 4, 2017 at 11:55:40 PM UTC-6, 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.