On Saturday, October 19, 2019 at 5:33:32 PM UTC+1, Matt McBee wrote:
The JS4 website says "performance polar standard class", but then under SAFETY describes automatic control hookups for flaperons.

So... what type of sailplane is this, and how is it different from the JS3? Does it have flaps or not?

Matt

Differences from the JS3 - the obvious ones on the link are larger wing area and different plan-form, poorer high speed performance and no flaps on the 3 view