AK-X swept wing sailplane

[Mike C]

Not much happening the past two years?

https://akaflieg-karlsruhe.de/tag/12-modell/

Anyone know of further progress?

Mike

[Gianni Isotope]

A couple of additional videos have been posted to their YouTube channel in the past year, including a rod control stress test last month,
https://www.youtube.com/channel/UCtk6WKPD-yeOH4Sl_Bjd4_A

[Charlie Quebec]

Just another waste of time and effort on the flying wing concept, and as usual, it will be worse than a normal sailplane of the same span area.

[AS]

On Tuesday, July 17, 2018 at 7:37:23 PM UTC-4, Charlie Quebec wrote:
> Just another waste of time and effort on the flying wing concept, and as usual, it will be worse than a normal sailplane of the same span area.

Thank god all the US-based AKAFLIEGs concentrate on solving real problems and are delivering only concepts which can be commercialized right away and thereby assure the survival of the vibrant domestic glider manufacturing base. >Sarcasm off<

Uli
'AS'

[Andreas Maurer]

On Tue, 17 Jul 2018 16:37:22 -0700 (PDT), Charlie Quebec
<mikesta...@gmail.com> wrote:

>Just another waste of time and effort on the flying wing concept, and as usual, it will be worse than a normal sailplane of the same span area.

Please elaborate - you seem to have far more knowledge about the AK-X
than anyone else.

Thank you very much
Andreas

[Bob Kuykendall]

You're welcome.

--Bob K.

[Eric Greenwell]

Charlie Quebec wrote on 7/17/2018 4:37 PM:
> Just another waste of time and effort on the flying wing concept, and as usual, it will be worse than a normal sailplane of the same span area.
>

Students pursuing the same thing the manufacturers are pursuing seems a like
bigger waste of time and effort. They are supposed to learning, and working on
difficult problems without the need to be profitable sounds like a good way to
achieve that learning.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/Guide-to-transponders-in-sailplanes-2014A.pdf

[BruceGreeff]

On 2018/07/19 06:45, Eric Greenwell wrote:
> Charlie Quebec wrote on 7/17/2018 4:37 PM:
>> Just another waste of time and effort on the flying wing concept, and
>> as usual, it will be worse than a normal sailplane of the same span area.
>>
> Students pursuing the same thing the manufacturers are pursuing seems a
> like bigger waste of time and effort. They are supposed to learning, and
> working on difficult problems without the need to be profitable sounds
> like a good way to achieve that learning.
>

Hi Eric

You have to think about this in the context of the German education system.
These projects are not part of the formal syllabus. They are voluntary,
additional projects.
The best compete to be able to participate in the AKAVlieg programmes,
where they get to apply their coursework to the practical
industrialisation - Design>Build>Evaluate of their ideas.

Consequently they turn out engineers with decent practical experience in
leading edge manufacture. Not a bad approach - especially considering
the direct engagement with peers, and product manufacturers, and
academics. These engineers and scientists also get to test their
product. Good for focussing the mind.

I doubt there is any pressure, expectation or ambition for their
experimental design to be a commercial success, Or even necessarily to
advance flight performance. It may be primarily about fabrication
techniques. This one could well be about controlability... Who knows.

Empirically he approach seems to work. The most recent, successful
startup in glider manufacture -Jonker Sailplanes uses exactly this model.

Bruce

[Andy Blackburn]

On Wednesday, July 18, 2018 at 11:45:06 AM UTC-7, Andreas Maurer wrote:
> On Tue, 17 Jul 2018 16:37:22 -0700 (PDT), Charlie Quebec
>

> >Just another waste of time and effort on the flying wing concept, and as usual, it will be worse than a normal sailplane of the same span area.
>
> Please elaborate - you seem to have far more knowledge about the AK-X
> than anyone else.
>
> Thank you very much
> Andreas

I was hoping to get an explanation of what "span area" is.

Andy

[Andreas Maurer]

On Thu, 19 Jul 2018 09:44:43 +0300, BruceGreeff <br...@wird.co.za>
wrote:

>Consequently they turn out engineers with decent practical experience in
>leading edge manufacture. Not a bad approach - especially considering
>the direct engagement with peers, and product manufacturers, and
>academics. These engineers and scientists also get to test their
>product. Good for focussing the mind.
>
>I doubt there is any pressure, expectation or ambition for their
>experimental design to be a commercial success, Or even necessarily to
>advance flight performance. It may be primarily about fabrication
>techniques. This one could well be about controlability... Who knows.
>
>Empirically he approach seems to work. The most recent, successful
>startup in glider manufacture -Jonker Sailplanes uses exactly this model.

... not to mention that ALL German glider designers since 1960 are
Akaflieg products, without exception. Guess where the German market
domnination came from...

Cheers Andreas

[golfsie...@gmail.com]

The Treaty of Versailles?

[AS]

On Tuesday, July 17, 2018 at 7:37:23 PM UTC-4, Charlie Quebec wrote:

> Just another waste of time and effort on the flying wing concept, and as usual, it will be worse than a normal sailplane of the same span area.

Here is another interesting AKAFLIEG project - this one is out of Stuttgart:
http://www.uni-stuttgart.de/akaflieg/projekte/die-flugzeuge/fs35-das-aktuelle-projekt/
They are developing a 150HP Diesel powered tow-capable motorglider to get gliders with ever increasing MTOWs into the sky.

Uli
'AS'

[Andreas Maurer]

On Thu, 19 Jul 2018 15:39:08 -0700 (PDT), golfsie...@gmail.com
wrote:

>The Treaty of Versailles?
>
>> Guess where the German market domnination came from...#

Yup. That famous treaty of Versailles after World War 2 that drove all
the other glider manufacturers out of the market in the 1970s.........

<sigh>

[Steve Leonard]

On Friday, July 20, 2018 at 6:07:55 AM UTC-5, AS wrote:
>
> Here is another interesting AKAFLIEG project - this one is out of Stuttgart:
> http://www.uni-stuttgart.de/akaflieg/projekte/die-flugzeuge/fs35-das-aktuelle-projekt/
> They are developing a 150HP Diesel powered tow-capable motorglider to get gliders with ever increasing MTOWs into the sky.
>
> Uli
> 'AS'

Maybe the bing translation isn't the greatest, but it is interesting to me that a country that does a significant amount of winch launching is looking to develop a towplane because "the winch can't meet all of our wants" when the country that uses primarily towplanes is heading towards doing more winching because "towplanes are too expensive".

I do like that project, though. Diesel to keep fuel cost and availability. Hopefully water cooled to reduce shock cooling issues. Hoping for big dive brakes to make descents much more rapid with airspeed kept low. With that much glass overhead, I wonder if they are considering some sort of airconditioning? Interesting choice on the airfoil section.

Oh, and my read of the spec sheet says they are looking at 180 HP. Even though in the title of the article, they say 155PS.

Good project, guys! Looking forward to seeing your results!

Steve Leonard

[AS]

Hi Steve,

your read is mostly correct. The main focus and driver for this project seems to be the contest crowd. Looking at the latest Super-Orchids and their wing-loading, the speed they require to stay on tow comfortable was cited to be up to 140km/h (87mph or 76kts), at which most commonly used tow planes over there have a close to zero climb rate. Not sure if that is correct, though - I am not blessed with one of these gliders ;-)
Anyhow, this Diesel-powered motorglider is supposed to come in two versions - 155HP and 180HP and is optimized for fast climb and descent rates. It will have a constant speed prop and will also feature an over-sized fuel tank to do as many tows as possible between fuel stops.
Your assessment of the winching situation is also correct. It is still the main method of getting gliders airborne over there, however, contests are almost 100% launched using tow planes - at least I haven't heard of any Nationals in Germany where a winch was used to launch the fleet. The costs of aero-towing in the US will go up as well due to rising fuel costs and a dwindling supply of crop-dusters, etc. Should be an interesting project to watch.

Uli
'AS'

[moshe....@gmail.com]

On Friday, July 20, 2018 at 7:19:53 AM UTC-4, Andreas Maurer wrote:
> On Thu, 19 Jul 2018 15:39:08 -0700 (PDT), g..@gmail.com

> wrote:
>
> >The Treaty of Versailles?
> >
> >> Guess where the German market domnination came from...#
>
> Yup. That famous treaty of Versailles after World War 2 that drove all
> the other glider manufacturers out of the market in the 1970s.........
>
> <sigh>

No, it's the imposed treaty at the end of WW1 that prohibited Germany from acquiring military airplanes. That pushed the Germans into developing and training in gliders instead, to prepare their future pilots. Thus the 1920's advances in gliders and soaring there, which gave them a head start in the field.

[herbk...@gmail.com]

Now that's funny, Andreas. Sadly, many here in the unwashed American West won't get it.

[WB]

No, no, no. The treaty of Versailles was the treaty, signed after WWI, that gave the French the right to build their own version of the ASW-19 seeing as how there own designs were, in the words of the treaty, “odd looking and not very good”.

[uncl...@ix.netcom.com]

On Friday, July 20, 2018 at 3:25:27 PM UTC-4, WB wrote:
> No, no, no. The treaty of Versailles was the treaty, signed after WWI, that gave the French the right to build their own version of the ASW-19 seeing as how there own designs were, in the words of the treaty, “odd looking and not very good”.

You Kill Me !
UH

[Dan Marotta]

There are plenty of cheap Cessna 182s in the US.  They can be fitted
with a tow hook and are probably less expensive to acquire and maintain
than an ag plane.

--
Dan, 5J

[Craig Funston]

C-182s start to run into problems with heavy gliders (750 to 850 kg) and at higher density altitudes. They are plentiful though and easier to find towpilots who qualify. Differing needs for differing sites.

It looked like the Akaflieg project was aimed at heavy gliders in contest type scenarios. Wilga's work well, but are pretty thirsty. Nothing like towing behind one of those beasts with a short tow rope..

Cheers,
Craig

[Steve Leonard]

On Friday, July 20, 2018 at 4:25:52 PM UTC-5, Craig Funston wrote:

> C-182s start to run into problems with heavy gliders (750 to 850 kg) and at higher density altitudes. They are plentiful though and easier to find towpilots who qualify. Differing needs for differing sites.
>
>

> Cheers,
> Craig

Not if it is an older one, set up for towing. Yeah, fly a new one, with full interior, loaded panel, and the kitchen sink, and they won't climb so well. Different planes for different purposes. :-)

Steve Leonard

[Craig Funston]

Agreed Steve. Akaflieg report made a point of saying weight is really important.

Craig

[Bruce Hoult]

I visited a site 12 months ago which had (if I counted correctly):

- 1x Grob Twin III
- 6x Blanik L13 (unmodified)
- 8x Wilga