Electric Towplane sets a new climb record

[Nick Kennedy]

Is this the future? No more shock cooling here!
https://newatlas.com/siemens-airbus-electric-plane-world-record-glider/48806/

[Dan Marotta]

I didn't see any mention of endurance in the article.Â* Did I miss it?

On 1/9/2018 4:30 PM, Nick Kennedy wrote:
> Is this the future? No more shock cooling here!
> https://newatlas.com/siemens-airbus-electric-plane-world-record-glider/48806/

--
Dan, 5J

[Renny[_2_]]

On Tuesday, January 9, 2018 at 4:30:12 PM UTC-7, Nick Kennedy wrote:
> Is this the future? No more shock cooling here!
> https://newatlas.com/siemens-airbus-electric-plane-world-record-glider/48806/

Nick - Indeed, the future is electric! Whether it is future towplanes or trainers like the Pipistrel Alpha Trainer, we will see more aircraft using electric motors. Gliders using the FES as a sustainer or as a self-launcher are already flying all over the world and have been flying for many years. We are seeing the development of the GP Gliders with electric self-launching capabilities which looks very interesting. Most of the major manufacturers now have gliders with electric capabilities including: Schempp-Hirth (including the new Ventus 3), JSC SportinÄ— Aviacija ir Ko (LAK gliders) HPH 304eS, Alisport Silent 2 Electro, Albastar, and now Schleicher with the ASG 32EL. Now are there issues? Absolutely! Is endurance and range a concern? Sure...The developers know this and there is a lot of work being done to help increase range via improved battery technology and other technical improvements.

We have definitely come a long way in the past 10 years, so just think where we will "be" 10 years from now!

Now, Nick...What you really need is more snow to fall in Telluride! (Maybe tonight!)
Thanks - Renny

[Surge]

On Wednesday, 10 January 2018 02:51:12 UTC+2, Renny wrote:
> We have definitely come a long way in the past 10 years, so just think where we will "be" 10 years from now!
>
> Now, Nick...What you really need is more snow to fall in Telluride! (Maybe tonight!)
> Thanks - Renny

I think electric is the way to go but I'm very sceptical about the improvements in battery technology.
I don't think we have come a long way in the past 10 years. All that is happening now is multiple manufactures are getting into the electric game using old, proven battery technologies.
Glider manufacturers are using lithium-ion or lithium-ion polymer battery technologies both of which where invented and developed in the 1970's and 1980's and then commercialized in the 1990's. There have been small improvements along the way but nothing ground breaking in the last 20 years.

Wake me up when someone manages to double or triple the specific energy (Joules/kg) of our current battery technologies.
The only promising technology I see on the horizon is rechargable, lithium metal batteries which MIT are busy working on.

[jfitch]

On Tuesday, January 9, 2018 at 9:09:17 PM UTC-8, Surge wrote:
> On Wednesday, 10 January 2018 02:51:12 UTC+2, Renny wrote:
> > We have definitely come a long way in the past 10 years, so just think where we will "be" 10 years from now!
> >
> > Now, Nick...What you really need is more snow to fall in Telluride! (Maybe tonight!)
> > Thanks - Renny
>
> I think electric is the way to go but I'm very sceptical about the improvements in battery technology.
> I don't think we have come a long way in the past 10 years. All that is happening now is multiple manufactures are getting into the electric game using old, proven battery technologies.
> Glider manufacturers are using lithium-ion or lithium-ion polymer battery technologies both of which where invented and developed in the 1970's and 1980's and then commercialized in the 1990's. There have been small improvements along the way but nothing ground breaking in the last 20 years.
>
> Wake me up when someone manages to double or triple the specific energy (Joules/kg) of our current battery technologies.
> The only promising technology I see on the horizon is rechargable, lithium metal batteries which MIT are busy working on.

Current electric self launchers are getting 10-15 minutes climb. Gas self launchers more like 60 - 90 minutes. So to match gas duration, you would need a 6x improvement in battery capacity. Now you only need what you need, but the gas tanks in gas self launchers weren't made extra large for fun.

[Dan Marotta]

On 1/9/2018 5:51 PM, Renny wrote:
> Now, Nick...What you really need is more snow to fall in Telluride! (Maybe tonight!)
> Thanks - Renny
>
And after 95 straight dry days, I'm finally seeing a tiny bit of snow
falling!
--
Dan, 5J

[Nick Kennedy]

During that record setting tow I wonder how hot those batterys got. Is that the limiting factor in producing power, the over heating of the batterys? Getting on the edge of combustion must be quite the worry for those guys.
Does anybody have a guess to the operating time at full power for that record setting Extra?

[[email protected]]

On Saturday, January 13, 2018 at 12:36:23 PM UTC-5, Nick Kennedy wrote:
> During that record setting tow I wonder how hot those batterys got. Is that the limiting factor in producing power, the over heating of the batterys? Getting on the edge of combustion must be quite the worry for those guys.
> Does anybody have a guess to the operating time at full power for that record setting Extra?

Motor temp is also a limiting factor. Get too hot and you can hurt the magnets based on what I've read.
UH

[Tony[_5_]]

My experience in the Electro in Uvalde and Kansas is that motor temp becomes an issue well before battery and controller temp.

[Dave Nadler]

On Sunday, January 14, 2018 at 8:32:19 AM UTC+13, Tony wrote:
> My experience in the Electro in Uvalde and Kansas is that motor temp
> becomes an issue well before battery and controller temp.

Depends on the machine. Antares has better motor cooling,
but batteries start to get hot and require early shutdown
at Uvalde for example (I typically shut down 800-1000 ft).
Perhaps cooling for enclosed FES motor isn't as good?

See ya, Dave

[[email protected]]

On Sunday, January 14, 2018 at 5:33:15 AM UTC-5, Dave Nadler wrote:
> On Sunday, January 14, 2018 at 8:32:19 AM UTC+13, Tony wrote:
> > My experience in the Electro in Uvalde and Kansas is that motor temp
> > becomes an issue well before battery and controller temp.
>
> Depends on the machine. Antares has better motor cooling,
> but batteries start to get hot and require early shutdown
> at Uvalde for example (I typically shut down 800-1000 ft).
> Perhaps cooling for enclosed FES motor isn't as good?
>
> See ya, Dave

Pylon mounted motor will obviously cool much more easily than enclosed motor cooled through a small hole. Each concept has it's trade offs.
UH

[[email protected]]

I wonder if one of these Sun Flyer trainers might work out? I like the engine of the 4 seater and the wing area of the 2 seater.
http://sunflyer.com/specifications/

Sure looks similar to the Dynamic Rotax powered towplane.

[Eric Greenwell[_4_]]

wrote on 1/17/2018 9:53 AM:
> I wonder if one of these Sun Flyer trainers might work out? I like the engine of the 4 seater and the wing area of the 2 seater.
> http://sunflyer.com/specifications/

I estimate they would have nearly the same climb rate with a 1000 lb sailplane, so
the much lower cost of the two seater would make it more attractive to most
operations. A "towplane version" might have a bigger battery pack for extra
duration without recharging, since it wouldn't need to carry baggage while towing.

And it ought to be easy to find towpilots - very zoomy, trike gear and no worries
about shock cooling the cylinders!

--
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

[AS]

On Thursday, January 18, 2018 at 9:25:57 AM UTC-5, Eric Greenwell wrote:
> wrote on 1/17/2018 9:53 AM:
> > I wonder if one of these Sun Flyer trainers might work out? I like the engine of the 4 seater and the wing area of the 2 seater.
> > http://sunflyer.com/specifications/
>
> I estimate they would have nearly the same climb rate with a 1000 lb sailplane, so
> the much lower cost of the two seater would make it more attractive to most
> operations. A "towplane version" might have a bigger battery pack for extra
> duration without recharging, since it wouldn't need to carry baggage while towing.
>
> And it ought to be easy to find towpilots - very zoomy, trike gear and no worries
> about shock cooling the cylinders!
>
> --
> 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

Could one recover some of the energy by using the motor as a generator on the way down - akin to regenerative braking on hybrid cars?
Uli
'AS'

[Soartech]

> Pylon mounted motor will obviously cool much more easily than enclosed motor cooled through a small hole. Each concept has it's trade offs.
> UH

Pylon mounting is the way to go. The FES self-launchers are VERY tricky to launch on a grass field because the prop tip is just a few inches off the ground. I have watched a friend blow up his prop on a grass field with just small bumps in it.
I like the new Polish GP series. The electric motor extends and retracts in just 4 seconds! Too bad there is a 2 year wait. The batteries are adequete now and will get better. There is a huge worldwide effort now to improve them.

[john firth]

On Tuesday, January 9, 2018 at 6:30:12 PM UTC-5, Nick Kennedy wrote:
> Is this the future? No more shock cooling here!
> https://newatlas.com/siemens-airbus-electric-plane-world-record-glider/48806/

Energy regeneration idea raises an engineering problem: how do you
optimise the total energy used?
A well designed prop for traction ( 80-90% power transfer) will be pretty poor
as a wind turbine .
A PhD to be won for designing a prop which maximises the energy transfer.
This includes glider in the equation.

JMF