Debunking Glider Spoiler Turns Causing Spin Thinking

On Thursday, June 4, 2015 at 11:34:35 PM UTC-5, wrote:

As an experiment try this at altitude: trim to the recommended approach speed with full airbrakes or recommended approach speed found in the AFM (or if it's not specified use the formula you were taught for choosing an approach speed), roll the glider into a good coordinated 40 degree bank turn then move the elevator progressively back. In every glider I've flown the elevator hits the stop without provoking a stall. I tried this after reading a Derek Piggott article suggesting it.

What is the result of the same test with airbrakes closed?


What do you need to do with the stick to hold a constant airspeed as you open the spoilers in wings-level flight?

Is the heart of the matter simply that for a given airspeed in wings-level at any given bank angle, including zero degrees bank, the stick needs to be positioned further aft with the spoilers open than with the spoilers closed?

S