On Friday, January 8, 2021 at 7:53:20 PM UTC-5, wrote:
The problem with the initial model of the ASw 20 spinning inadvertently was caused by poor pilot training coupled with this idea that having the CG way aft was the way to go.
Pilots would put down the 55 degree flaps and forget or just not, trim for a pattern speed hands off.
The flaps are large, and if you put them full down and forget to trim and get distracted and let go of the forward pitch pressure the plane will rapidly slow down and stall. Coupled with low altitude and a full aft CG this situation was a recipe for disaster. And yes, there were several accidents.
When I got my ASw 20 check out this issue was beat into me by a couple of sharp cookies.
I never had a problem.
The fully rear CG thing is interesting, working with Tom Brenza in MoriarityNM I started out at about 50% aft for about 60 hours. Then I went to about 85% aft. Then, I thought anyway, doing alot of high speed cruising at 17+ out west my plane climbed great and ran best at about 60% aft CG.
Every thing I have owned easily spins, Except our ASK 21- My Blanik L-13 was a great ship to do as many spins as you wanted in both directions. My Ka6 CR was really good at controllable multiple, long duration spins, as is my LS3a.
I spent a Fall living in Fort Collins Co and got checked out in their C-150.
I would come over CX house high and spin that thing like crazy, musta done 200+ in that thing and got really comfortable doing them.
Nick
T
I owned 20's for about 15 years. Early experience showed that far aft CG made it much more prone to departure into a spin.
Over time I learned:
1- I put the CG at the point where I could turn as tightly as I wanted without running out of elevator at thermalling speed. That turned out to be about 80% aft. Stall spin characteristics were pretty benign.
2- Adding internal and external seals to wing controls meaningfully improved handling and stall/spin characteristic.
3- Good winglets make handling better and stall/spin more benign, up until the glider spins. After a spin is initiated, winglets can make it more abrupt.

After I took delivery of my first 20, I test flew it and it spun almost without warning out of a normal stall. Investigation found 15 lb of lead in the tail that was not documented. The previous owner said he only flew it with water and it was fine for him. The lesson I came away with is at least weigh the tail of any ship new to you to see if the weight agrees with your weight and balance. If not, investigate before becoming an involuntary test pilot.

UH