On Tuesday, October 27, 2015 at 11:29:25 PM UTC+3, Steve Leonard wrote:
I love big deflection flaps, but am hesitant to recommend them to others. I see too many people flying them "wrong". At least, in my opinion. Too many people fly the entire approach slower "because the stall speed is lower". The plane should not be level coming over the fence with the flaps down 45 degrees. And then they claim "You can't retract the flaps if you get low".

Yes, that's dumb and I never understood people who claim this.

The approach speed should always be calculated from the clean stall speed, not the full flap stall speed! Then you can safely put the flaps up and down as much as you want.

You do need to remember to adjust the glider's attitude when you do it otherwise, yes, you will "sink" if you bring the flaps up. When I was regularly flying a flapped glider I practiced at altitude quickly going in and out of landing flap without a change of G loading. It's not that hard, but you do have to know to do it.