The EB29 with 25M span is listed at 63, same as the 21 M span JS2. Four more
meters doesn't buy you what it used to!

jfitch wrote on 10/6/2020 8:39 AM:
They are claiming 63:1, that is 7 points higher than AS claim of 56:1. I think it is best explained by a mistake in their math. I'd be interested in seeing the test data proving it.

On Tuesday, October 6, 2020 at 12:53:25 AM UTC-7, Carlo Orsini wrote:
Thank you for your first hand infos, those are good news for me (I don't understand why they advertise these dimensions in a different way). JS2 seems to be a nice project overall. Hard to me to understand where they streched out those +4 points of efficency in 21m, according to their calculated polars, compared to ASH31 (yes I know that '31 profiles are a bit superseeded and the aspect ratio is a factor too but 4 points are a huge amount!!).
Those two dimensions for the JS2 and the ASH31 are clearly not be comparable - one internal cockpit rim and one external I guess. The 525mm shoulder width for the JS2 is exactly the same as the quoted figure for the JS1 (and JS3) and the JS1 cockpit roominess is fully equal to the ASH26/31 from which it was derived. I have 4 years in a JS1 followed by 2 in the ASH 26e and they are so similar that it would be hard to know which cockpit I was in with my eyes closed. Looking at the JS2 cockpit photographs it obvious that its structural cockpit rim design is the same as the 31, 26 and JS1. JS do not make small cockpits.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1