Andy, see below my comments in line


Chris,

Thanks for taking the time to post this report.

It seems that the test aircraft is very unforgiving of poor recovery
technique. Is this typical of modern 15m ships?


Of those I've flown, yes and no. Most are very resistant to stalling
if the yaw string is straight back. They will mush rathar than
departing. However, they are all intolerant of improper recovery. Note
that in my coordinated turning stalls I initiated no recovery. I
simply let the glider seeks its own path. By keeping the ailerons and
rudder neutral, I was letting the tail do its job -- that is,
providing stability. (It was my original contention that if you didn't
stick an aileron into the airstream, the stalled wing couldn't produce
enough drag to overpower the tail.)

I have always entered spins through a misapplication of the controls.
Various models differ in the amount of misuse they'll tolerate. For
example, a Lark IS-28 will spin if you stick your hand out the clear
view in a left turning stall (only a slight exageration). The Grob 103
has only a very small spin entry window -- to the point that most
pilots don't have the patience to find it and thus pronounce it
unspinnable. And yet, once in the spin, the 103 is perhaps the most
interesting. (The SGS 1-26E is, in my opinion, the ultimate spin
training platform. Easy entry (big ailerons), easy recovery (just let
go), and a very stable spinning motion that lets you get used to
attitude and rotation rate. Only disadvantage is that you'll be
teaching yourself. Start high.)



How would it have
behaved in the same situation with a full ballast load?

So long as the CG remains the same, yes, I think so. But recovery
would, in all cases, require more altitude. Frankly, I don't do much
experimenting with water on board. I am too heavy to fly at or below
gross with full tanks, and I don't like the idea of flinging 2/3 of a
tank of water out to the tip during a spin. That assymetry would only
add to the altitude I'd eat up during recovery.



When I transitioned from the ASW-19 to the ASW-28 I explored its
characteristics in turning stalls at the aft cg limit and found, just
like the 19, it was benign even with abused control inputs.

The 19 is a pussycat. And though I haven't flown the 28 yet, I bet
it's even sweeter.


Andy (GY)