Jonker JS4 Details

https://jonkersailplanes.co.za/js4/

On Thursday, October 17, 2019 at 9:30:06 PM UTC-7, Paul T wrote:
https://jonkersailplanes.co.za/js4/

What happened to the self-launching 18m/21m JS2?
Jim

At 05:05 18 October 2019, JS wrote:
On Thursday, October 17, 2019 at 9:30:06 PM UTC-7, Paul T wrote:
https://jonkersailplanes.co.za/js4/

What happened to the self-launching 18m/21m JS2?
Jim

https://jonkersailplanes.co.za/js2/ and
https://jonkersailplanes.co.za/2019/...roject-update/

Looks like AS34Me competitor with 20 years more recent aerodynamics, interesting. Lets see the weight the thing, especially SL electric version (not that JS would tell that, though).

JS4 has a retractable electric motor instead of FES and it can self launch.

“The JS4 will be available with the jet sustainer system as well as the new electric self-launch motor option which retracts into the fuselage for low-drag ultimate performance.“

Getting some extra mileage out of all that fuselage and wing work on the JS3. I’m guessing the electric motor might go in the JS3 as well unless the flap mixer gets in the way since it’s otherwise the same fuselage. They had been talking FES previously as an option for the JS3.

All that leaves is a high-performance two-seater - unless they want to try to crack the trainer market.

Admirable efforts.

Andy Blackburn

At 09:32 18 October 2019, Andy Blackburn wrote:
JS4 has a retractable electric motor instead of FES and it can self
launch.

=E2=80=9CThe JS4 will be available with the jet sustainer system
as well
as=
the new electric self-launch motor option which retracts into the
fuselage=
for low-drag ultimate performance.=E2=80=9C

Getting some extra mileage out of all that fuselage and wing work
on the
JS=
3. I=E2=80=99m guessing the electric motor might go in the JS3
as well
unle=
ss the flap mixer gets in the way since it=E2=80=99s otherwise
the same
fus=
elage. They had been talking FES previously as an option for the
JS3.=20

All that leaves is a high-performance two-seater - unless they want
to try
=
to crack the trainer market.

Admirable efforts.

Andy Blackburn

A JS5 is listed as a product coming in 2024?????

On Friday, October 18, 2019 at 2:32:56 AM UTC-7, Andy Blackburn wrote:
JS4 has a retractable electric motor instead of FES and it can self launch.

“The JS4 will be available with the jet sustainer system as well as the new electric self-launch motor option which retracts into the fuselage for low-drag ultimate performance.“

Getting some extra mileage out of all that fuselage and wing work on the JS3. I’m guessing the electric motor might go in the JS3 as well unless the flap mixer gets in the way since it’s otherwise the same fuselage. They had been talking FES previously as an option for the JS3.

All that leaves is a high-performance two-seater - unless they want to try to crack the trainer market.

Admirable efforts.

Andy Blackburn

I would love to see Jonker's original thought on high performance two place.. And if you haven't shared a flight in a high performance two place you should put that on your list. My funnest flights have been in one hole of an open two holer.

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

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

At 17:07 19 October 2019, wrote:
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


Errors whilst updating the website - a lot of things where different
yesterday i.e. 'open class polar' - looked like things had been copied
and pasted over from other descriptions -some links are still not
working correctly etc., the JS4 is definitely a std class machine by all
accounts.