On Tuesday, March 15, 2016 at 3:52:27 PM UTC-5, Papa3 wrote:
There are 4 curves in total: L/D solo (wingloading at 5.67 lbs/sqft) and dual (7.44 lbs/sqft). Those are read against the left Y axis. Sink rate solo and dual. Those are read against the right Y axis. As far as the bands, I suspect it's "truth in advertising" by Schweizer; i.e. "it's our calculated L/D so don't hold us to it" :-)

And the upper curves are the L/D curves. Well, upper at the left hand side of the chart. The lower curves are the sink rate curves.

Don't you just love the optimism of showing best speed to fly for next expected thermal of up to 1600 feet per minute!

Steve Leonard