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I thought the same thing...............before checking width between shoulders on JS2!

Paul T wrote on 10/3/2020 12:56 AM:
....................
personally I'd have a JS2/5 if I win the lottery.

The JS1 and ASH26 I used to fly were noticeably more roomy around the shoulders and upper arms than the V3M and I would be amazed if the JS2 wasn't similar. The Ventus Performance fuselage has a vertical side wall for a few inches below the cockpit rim whereas the JS gliders follow the Schleicher concept of a reinforcing inward curvature of the cockpit rim beneath which the shoulder and elbow-moving space is quite roomy. I wouldn't reject the JS2 on cockpit size alone without sitting in it first. Oscar Goudrian fits according to the picture on the JS FB page.

JS2 spec:
Cockpit shoulder width
525 mm

ASH31Mi spec:
Cockpit width
660 mm

Yes, there is a photo of Goudriaan in the cockpit: his position is completely lying down with shoulders under the rims. I don't think you could fly 10 hours in that position IMHO.

When talking about aerodynamic drag the fuselage frontal area is an important factor, especially at high speeds (when induced drag is less).

A pilot must take a decision: top performance or compromise & comfort ? Both is simply impossible.

(This was a factor when I had to choose between ASH31Mi and Ventus2CxM)

On Monday, 5 October 2020 at 15:38:53 UTC+1, Carlo Orsini wrote:
JS2 spec:
Cockpit shoulder width
525 mm

ASH31Mi spec:
Cockpit width
660 mm

Yes, there is a photo of Goudriaan in the cockpit: his position is completely lying down with shoulders under the rims. I don't think you could fly 10 hours in that position IMHO.

When talking about aerodynamic drag the fuselage frontal area is an important factor, especially at high speeds (when induced drag is less).

A pilot must take a decision: top performance or compromise & comfort ? Both is simply impossible.

(This was a factor when I had to choose between ASH31Mi and Ventus2CxM)

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.

It should not come as a surprise that the JS1/JS2 cockpits are similar to the ASH26, given that they took a splash mold off of a 26 fuselage to build them. They seem identical because they are.

On Monday, October 5, 2020 at 9:22:34 AM UTC-7, wrote:
On Monday, 5 October 2020 at 15:38:53 UTC+1, Carlo Orsini wrote:
JS2 spec:
Cockpit shoulder width
525 mm

ASH31Mi spec:
Cockpit width
660 mm

Yes, there is a photo of Goudriaan in the cockpit: his position is completely lying down with shoulders under the rims. I don't think you could fly 10 hours in that position IMHO.

When talking about aerodynamic drag the fuselage frontal area is an important factor, especially at high speeds (when induced drag is less).

A pilot must take a decision: top performance or compromise & comfort ? Both is simply impossible.

(This was a factor when I had to choose between ASH31Mi and Ventus2CxM)
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.

On Monday, 5 October 2020 at 20:16:15 UTC+1, jfitch wrote:
It should not come as a surprise that the JS1/JS2 cockpits are similar to the ASH26, given that they took a splash mold off of a 26 fuselage to build them. They seem identical because they are.
On Monday, October 5, 2020 at 9:22:34 AM UTC-7, wrote:
On Monday, 5 October 2020 at 15:38:53 UTC+1, Carlo Orsini wrote:
JS2 spec:
Cockpit shoulder width
525 mm

ASH31Mi spec:
Cockpit width
660 mm

Yes, there is a photo of Goudriaan in the cockpit: his position is completely lying down with shoulders under the rims. I don't think you could fly 10 hours in that position IMHO.

When talking about aerodynamic drag the fuselage frontal area is an important factor, especially at high speeds (when induced drag is less).

A pilot must take a decision: top performance or compromise & comfort ? Both is simply impossible.

(This was a factor when I had to choose between ASH31Mi and Ventus2CxM)
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.

Indeed they are - as I said.

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.

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.

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

At 15:39 06 October 2020, jfitch wrote:
They are claiming 63:1, that is 7 points higher than AS claim of 56:1. I
th=
ink it is best explained by a mistake in their math. I'd be interested in
s=
eeing the test data proving it.=20

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
see=
ms to be a nice project overall. Hard to me to understand where they
strech=
ed out those +4 points of efficency in 21m, according to their
calculated
p=
olars, compared to ASH31 (yes I know that '31 profiles are a bit
superseede=
d 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
compa=
rable - one internal cockpit rim and one external I guess. The 525mm
should=
er 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
i=
n with my eyes closed. Looking at the JS2 cockpit photographs it
obvious
th=
at its structural cockpit rim design is the same as the 31, 26 and JS1.
JS
=
do not make small cockpits.

I believe the Idafleig measured a JS1C at 63:1......so the JS2 witH its
few improvements on the JS1C should achieve that....