GOAT ASW20

wrote on 1/10/2021 4:26 PM:
On Sunday, January 10, 2021 at 7:37:11 AM UTC-8, Eric Greenwell wrote:
wrote on 1/10/2021 6:35 AM:
On Sunday, January 10, 2021 at 6:00:08 AM UTC-8, Hank Nixon wrote:

....


Found an article that claims the '20 spins like a top with landing gear down and landing flaps
selected, but is stable otherwise:

http://flsc.org/portals/12/PDF/Spinning.pdf
I'm surprised to hear that it will spin readily with the full landing flap, because that also
puts the ailerons into negative deflection. That makes it very difficult to stall the tips, a
usual condition for spinning. Perhaps the full deflection affects the airflow over the tail,
and that is cause?

The reason I heard the reason for changing from 60 degree deflection to 40 degrees was to avoid
damage to the flap rods in a hard landing, which was often undetected until the next landing.
Selecting full deflection would then fully deflect only one flap, giving a strong rolling
motion and a very surprised pilot.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
The biggest reason for reduced flap deflection was to prevent damage to the newly implemented gap seals, originally metal and soon after polyester (Mylar).
My experience agrees with Eric in that landing flap makes the ship more docile, not less.
UH
I’ll go out and stall my 20 with full flaps this spring when I get it put back together.

I hope you have the original 20 with the 60 degree flaps and are willing to try turning stalls.
My 20C, with 40 degree flaps, was hard to stall straight ahead, and remained controllable. I
don't recall trying any turning stalls in landing configuration, so I'd like to know how the
"A" model compares to the B or C model.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
Yep I have an early “A” model. I’ll get up high this spring and see how it goes. I don’t recall if I did a full flap stall when I initially checked myself out.

Doing it with/without the spoilers open (as is normal for landing), may produce quite different
results, so be careful up there.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1