On Thursday, September 2, 2021 at 9:07:03 AM UTC-7, jfitch wrote:
> On Wednesday, September 1, 2021 at 9:46:57 AM UTC-7, Moshe Braner wrote:
> > Where do people get the idea that if the prop is free to spin it adds
> > "NO" drag?
> I don't think anyone has that idea. An unpowered prop creates drag, the question originally was, does it create extraordinary or "extra" drag on an airplane? Of course not, it is part of the design, is always present, has been present every time you flew it, is today no different than yesterday, and is by definition ordinary. There are not two modes: prop deployed and prop stowed, as there might be in a glider. That degenerated into: does a spinning prop create more drag than a stopped one. You can do all the internet speculation you want, but this has been tested, many times, for many configurations. The answer is not yes or no, it is "it depends" on the specific conditions.
>
> The energy lost in a stopped prop is fairly easy to calculate. A spinning prop is considerably more complicated. To spin it at exactly the critical speed to create zero lift on its blades, you must overcome only the profile drag of the blades, similar to running a variable pitch on the ground set to zero pitch. At this speed it creates no drag (to a first order at least).. The power required to spin it at that speed is the energy lost, as it must be extracted from the airstream which means it must be spinning slower that the critical speed, creating some drag. If the shaft has torque drag due to turning an engine, more power is required, creating more drag. The calculations become quite complex. From empirical measurements, we know that it may, or may not be more drag than the same prop stopped, depending on a number of factors unique to the installation and operating conditions.

I can tell you that to spin a stopped prop takes something over 90 kt. This is going to create a hell of a lot drag but that is what you want to do if you want to restart the engine using the windmilling method, but below that the prop WILL NOT spin.

Tom

Hi all

Just posting this for information, some progress being made in fighting Battery fires with a new product developed in Switzerland

https://protect.ibena.de/de/news/wenn-ein-elektro-auto-brennt-trockene-loesung-fuer-ein-heisses-problem.html

Google Translate will do a reasonable translation Job.

I have no opinion or comment or commercial interest in this product.

Muttley

On Fri, 10 Sep 2021 15:28:02 -0700, Muttley wrote:

> Hi all
>
> Just posting this for information, some progress being made in fighting
> Battery fires with a new product developed in Switzerland
>
> https://protect.ibena.de/de/news/wenn-ein-elektro-auto-brennt-trockene-
loesung-fuer-ein-heisses-problem.html
>
> Google Translate will do a reasonable translation Job.
>
...... or just click 'EN' on the top line and then scroll down to see the
English page. Its rare for European web pages not to be multilingual.
Interesting write-up, too.

--
--
Martin | martin at
Gregorie | gregorie dot org

On 9/10/21 4:28 PM, Muttley wrote:
> Hi all
>
> Just posting this for information, some progress being made in fighting Battery fires with a new product developed in Switzerland
>
> https://protect.ibena.de/de/news/wenn-ein-elektro-auto-brennt-trockene-loesung-fuer-ein-heisses-problem.html
>
> Google Translate will do a reasonable translation Job.
>
> I have no opinion or comment or commercial interest in this product.
>
> Muttley
>

That's nothing. Those crafty Frenchmen have come up with a solution
that cuts a three hour fire-fight down to 5 minutes:

www.engadget.com/renault-megane-e-tech-electric-battery-fire-access-safety-163050987.html

Plus, they've got a switch under the rear seat for the ultimate in safety.

If that weren't enough, they actually put a QR code right on the
windshield so that firefighters can study a web site.

On Thursday, September 2, 2021 at 6:18:39 PM UTC-7, 2G wrote:
> I can tell you that to spin a stopped prop takes something over 90 kt. This is going to create a hell of a lot drag but that is what you want to do if you want to restart the engine using the windmilling method, but below that the prop WILL NOT spin.
>
> Tom
You are unlikely to be able to restart your electric motor using the windmill method, no matter how fast you dive.

....Unless it's got regenerative windmilling and you start very, very high.

Dan
5J

On 9/11/21 1:41 PM, jfitch wrote:
> On Thursday, September 2, 2021 at 6:18:39 PM UTC-7, 2G wrote:
>> I can tell you that to spin a stopped prop takes something over 90 kt. This is going to create a hell of a lot drag but that is what you want to do if you want to restart the engine using the windmilling method, but below that the prop WILL NOT spin.
>>
>> Tom
> You are unlikely to be able to restart your electric motor using the windmill method, no matter how fast you dive.

On Saturday, September 11, 2021 at 2:41:28 PM UTC-7, Dan Marotta wrote:
> ...Unless it's got regenerative windmilling and you start very, very high.
>
> Dan
> 5J
> On 9/11/21 1:41 PM, jfitch wrote:
> > On Thursday, September 2, 2021 at 6:18:39 PM UTC-7, 2G wrote:
> >> I can tell you that to spin a stopped prop takes something over 90 kt. This is going to create a hell of a lot drag but that is what you want to do if you want to restart the engine using the windmilling method, but below that the prop WILL NOT spin.
> >>
> >> Tom
> > You are unlikely to be able to restart your electric motor using the windmill method, no matter how fast you dive.

If you were very, very high you wouldn't need the motor.

Tom

User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <62f0d0e6-a1bc-4613-afa1-9f41a3d30acdn@googlegroups.com>
Subject: Re: How to fight a lithium battery fire
From: jfitch <jfitch@flash.net>
Injection-Date: Mon, 16 Aug 2021 05:52:49 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Lines: 32
Xref: i2pn2.org rec.aviation.soaring:27773

On Sunday, August 15, 2021 at 8:38:13 PM UTC-7, 2G wrote:
> On Sunday, August 15, 2021 at 6:42:39 PM UTC-7, jfitch wrote:=20
> > On Sunday, August 15, 2021 at 5:52:38 PM UTC-7, 2G wrote:=20
> > > The NZ Taurus Electro exploded in mid-air.=20
> > >=20
> > > Tom=20
> > You seem to be reading a lot of things into the NZ accident report that=
aren't there. It did not explode in mid-air. There is speculation in the r=
eport that fumes may have contributed but no forensic evidence and that is =
not in the conclusions in the report. It is known that the owner did not fo=
llow the safety cautions on maintaining the battery.=20
> >=20
> > One question I am left with after reading the report: would that aircra=
ft have an ejectable canopy? Maybe not because of the ballistic parachute? =
It seems like a temporary solution to fumes in the canopy would be to get r=
id of it. Speeding back to the airport at over redline did not work.
> You can call it a fire or you can call it an explosion - whatever it was =
it was very violent. The photo of the battery box showed delamination. The =
heat damage included the seat pan and rudder control cables. The pilot lost=
complete of the glider less than one mile from the airfield - why? He coul=
d have made an emergency landing in only one minute, or he could have used =
the ballistic chute, which he did not. The only explanation that makes sens=
e is that he was incapacitated by fumes from the fire.=20
>=20
> They call them battery fires, but what happens after an internal short is=
the pressure inside the cell builds rapidly until the cell ruptures violen=
tly. I call that an explosion.=20
>=20
> Tom
Not going to argue with you, I'd just encourage anyone interested to read t=
he report, the link is referenced above, it is in plain English and very cl=
ear. The conclusions you are drawing are highly speculative, the report is=
not and does not draw those conclusions.

User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <62f0d0e6-a1bc-4613-afa1-9f41a3d30acdn@googlegroups.com>
Subject: Re: How to fight a lithium battery fire
From: jfitch <jfitch@flash.net>
Injection-Date: Mon, 16 Aug 2021 05:52:49 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Lines: 32
Xref: i2pn2.org rec.aviation.soaring:27773

On Sunday, August 15, 2021 at 8:38:13 PM UTC-7, 2G wrote:
> On Sunday, August 15, 2021 at 6:42:39 PM UTC-7, jfitch wrote:=20
> > On Sunday, August 15, 2021 at 5:52:38 PM UTC-7, 2G wrote:=20
> > > The NZ Taurus Electro exploded in mid-air.=20
> > >=20
> > > Tom=20
> > You seem to be reading a lot of things into the NZ accident report that=
aren't there. It did not explode in mid-air. There is speculation in the r=
eport that fumes may have contributed but no forensic evidence and that is =
not in the conclusions in the report. It is known that the owner did not fo=
llow the safety cautions on maintaining the battery.=20
> >=20
> > One question I am left with after reading the report: would that aircra=
ft have an ejectable canopy? Maybe not because of the ballistic parachute? =
It seems like a temporary solution to fumes in the canopy would be to get r=
id of it. Speeding back to the airport at over redline did not work.
> You can call it a fire or you can call it an explosion - whatever it was =
it was very violent. The photo of the battery box showed delamination. The =
heat damage included the seat pan and rudder control cables. The pilot lost=
complete of the glider less than one mile from the airfield - why? He coul=
d have made an emergency landing in only one minute, or he could have used =
the ballistic chute, which he did not. The only explanation that makes sens=
e is that he was incapacitated by fumes from the fire.=20
>=20
> They call them battery fires, but what happens after an internal short is=
the pressure inside the cell builds rapidly until the cell ruptures violen=
tly. I call that an explosion.=20
>=20
> Tom
Not going to argue with you, I'd just encourage anyone interested to read t=
he report, the link is referenced above, it is in plain English and very cl=
ear. The conclusions you are drawing are highly speculative, the report is=
not and does not draw those conclusions.

User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <62f0d0e6-a1bc-4613-afa1-9f41a3d30acdn@googlegroups.com>
Subject: Re: How to fight a lithium battery fire
From: jfitch <jfitch@flash.net>
Injection-Date: Mon, 16 Aug 2021 05:52:49 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Lines: 32
Xref: i2pn2.org rec.aviation.soaring:27773

On Sunday, August 15, 2021 at 8:38:13 PM UTC-7, 2G wrote:
> On Sunday, August 15, 2021 at 6:42:39 PM UTC-7, jfitch wrote:=20
> > On Sunday, August 15, 2021 at 5:52:38 PM UTC-7, 2G wrote:=20
> > > The NZ Taurus Electro exploded in mid-air.=20
> > >=20
> > > Tom=20
> > You seem to be reading a lot of things into the NZ accident report that=
aren't there. It did not explode in mid-air. There is speculation in the r=
eport that fumes may have contributed but no forensic evidence and that is =
not in the conclusions in the report. It is known that the owner did not fo=
llow the safety cautions on maintaining the battery.=20
> >=20
> > One question I am left with after reading the report: would that aircra=
ft have an ejectable canopy? Maybe not because of the ballistic parachute? =
It seems like a temporary solution to fumes in the canopy would be to get r=
id of it. Speeding back to the airport at over redline did not work.
> You can call it a fire or you can call it an explosion - whatever it was =
it was very violent. The photo of the battery box showed delamination. The =
heat damage included the seat pan and rudder control cables. The pilot lost=
complete of the glider less than one mile from the airfield - why? He coul=
d have made an emergency landing in only one minute, or he could have used =
the ballistic chute, which he did not. The only explanation that makes sens=
e is that he was incapacitated by fumes from the fire.=20
>=20
> They call them battery fires, but what happens after an internal short is=
the pressure inside the cell builds rapidly until the cell ruptures violen=
tly. I call that an explosion.=20
>=20
> Tom
Not going to argue with you, I'd just encourage anyone interested to read t=
he report, the link is referenced above, it is in plain English and very cl=
ear. The conclusions you are drawing are highly speculative, the report is=
not and does not draw those conclusions.

User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <62f0d0e6-a1bc-4613-afa1-9f41a3d30acdn@googlegroups.com>
Subject: Re: How to fight a lithium battery fire
From: jfitch <jfitch@flash.net>
Injection-Date: Mon, 16 Aug 2021 05:52:49 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Lines: 32
Xref: i2pn2.org rec.aviation.soaring:27773

On Sunday, August 15, 2021 at 8:38:13 PM UTC-7, 2G wrote:
> On Sunday, August 15, 2021 at 6:42:39 PM UTC-7, jfitch wrote:=20
> > On Sunday, August 15, 2021 at 5:52:38 PM UTC-7, 2G wrote:=20
> > > The NZ Taurus Electro exploded in mid-air.=20
> > >=20
> > > Tom=20
> > You seem to be reading a lot of things into the NZ accident report that=
aren't there. It did not explode in mid-air. There is speculation in the r=
eport that fumes may have contributed but no forensic evidence and that is =
not in the conclusions in the report. It is known that the owner did not fo=
llow the safety cautions on maintaining the battery.=20
> >=20
> > One question I am left with after reading the report: would that aircra=
ft have an ejectable canopy? Maybe not because of the ballistic parachute? =
It seems like a temporary solution to fumes in the canopy would be to get r=
id of it. Speeding back to the airport at over redline did not work.
> You can call it a fire or you can call it an explosion - whatever it was =
it was very violent. The photo of the battery box showed delamination. The =
heat damage included the seat pan and rudder control cables. The pilot lost=
complete of the glider less than one mile from the airfield - why? He coul=
d have made an emergency landing in only one minute, or he could have used =
the ballistic chute, which he did not. The only explanation that makes sens=
e is that he was incapacitated by fumes from the fire.=20
>=20
> They call them battery fires, but what happens after an internal short is=
the pressure inside the cell builds rapidly until the cell ruptures violen=
tly. I call that an explosion.=20
>=20
> Tom
Not going to argue with you, I'd just encourage anyone interested to read t=
he report, the link is referenced above, it is in plain English and very cl=
ear. The conclusions you are drawing are highly speculative, the report is=
not and does not draw those conclusions.

User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <62f0d0e6-a1bc-4613-afa1-9f41a3d30acdn@googlegroups.com>
Subject: Re: How to fight a lithium battery fire
From: jfitch <jfitch@flash.net>
Injection-Date: Mon, 16 Aug 2021 05:52:49 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Lines: 32
Xref: rocksolid2 rec.aviation.soaring:27690

On Sunday, August 15, 2021 at 8:38:13 PM UTC-7, 2G wrote:
> On Sunday, August 15, 2021 at 6:42:39 PM UTC-7, jfitch wrote:=20
> > On Sunday, August 15, 2021 at 5:52:38 PM UTC-7, 2G wrote:=20
> > > The NZ Taurus Electro exploded in mid-air.=20
> > >=20
> > > Tom=20
> > You seem to be reading a lot of things into the NZ accident report that=
aren't there. It did not explode in mid-air. There is speculation in the r=
eport that fumes may have contributed but no forensic evidence and that is =
not in the conclusions in the report. It is known that the owner did not fo=
llow the safety cautions on maintaining the battery.=20
> >=20
> > One question I am left with after reading the report: would that aircra=
ft have an ejectable canopy? Maybe not because of the ballistic parachute? =
It seems like a temporary solution to fumes in the canopy would be to get r=
id of it. Speeding back to the airport at over redline did not work.
> You can call it a fire or you can call it an explosion - whatever it was =
it was very violent. The photo of the battery box showed delamination. The =
heat damage included the seat pan and rudder control cables. The pilot lost=
complete of the glider less than one mile from the airfield - why? He coul=
d have made an emergency landing in only one minute, or he could have used =
the ballistic chute, which he did not. The only explanation that makes sens=
e is that he was incapacitated by fumes from the fire.=20
>=20
> They call them battery fires, but what happens after an internal short is=
the pressure inside the cell builds rapidly until the cell ruptures violen=
tly. I call that an explosion.=20
>=20
> Tom
Not going to argue with you, I'd just encourage anyone interested to read t=
he report, the link is referenced above, it is in plain English and very cl=
ear. The conclusions you are drawing are highly speculative, the report is=
not and does not draw those conclusions.

Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.

I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.

Finally, that is an electric self launcher with an endurance greater than I have ever needed.

If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?

Mark Burton

On Saturday, October 16, 2021 at 7:10:53 AM UTC-4, waremark wrote:
> Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.
>
> I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.
>
> Finally, that is an electric self launcher with an endurance greater than I have ever needed.
>
> If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?
>
> Mark Burton
Recent test in Nordic Gliding https://nordicgliding-com.translate.goog/test-lange-antares-21-e/?_x_tr_sl=da&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui%2Celem&fbclid=IwAR04nZGUDNOXgiwxrcK2sVQrA3YDAyYy6dfODBEY_xXFFqa80q8A34C-KTo

On 10/16/2021 4:10 AM, waremark wrote:
> Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.
>
> I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.
>
> Finally, that is an electric self launcher with an endurance greater than I have ever needed.
>
> If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?
>
> Mark Burton
>
This thread is already unwieldy and suffered multiple drifting. Let's discuss the new
Antares in a new thread, which I will attempt to start.

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

On Saturday, October 16, 2021 at 4:10:53 AM UTC-7, waremark wrote:
> Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.
>
> I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.
>
> Finally, that is an electric self launcher with an endurance greater than I have ever needed.
>
> If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?
>
> Mark Burton

I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.

Tom

> I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.
>

Actually Dick still flies his Antares regularly, though this year he's been mostly flying the Arcus.

Mike B.

On 10/16/21 10:48 PM, Michael Bamberg wrote:
>
>> I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.
>>
>
> Actually Dick still flies his Antares regularly, though this year he's been mostly flying the Arcus.
>
> Mike B.
>

His last 54 postings on OLC are all with an Arcus, so maybe his
dedication to the Antares is waning.

Nadler (former U.S. dealer) had a really nice flight last spring, but
put this in his posting:

This is the 6th flight since 2020's extensive rework to engineer around
assorted Lange design problems. And - today it had another failure
(thermal fuse). The new glider is almost here, so this may be my last
flight in this glider, I'm just too tired of fixing it. Most likely it
will go to a museum.

On Saturday, October 16, 2021 at 10:33:31 PM UTC-7, kinsell wrote:
> On 10/16/21 10:48 PM, Michael Bamberg wrote:
> >
> >> I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.
> >>
> >
> > Actually Dick still flies his Antares regularly, though this year he's been mostly flying the Arcus.
> >
> > Mike B.
> >
> His last 54 postings on OLC are all with an Arcus, so maybe his
> dedication to the Antares is waning.
>
> Nadler (former U.S. dealer) had a really nice flight last spring, but
> put this in his posting:
>
>
> This is the 6th flight since 2020's extensive rework to engineer around
> assorted Lange design problems. And - today it had another failure
> (thermal fuse). The new glider is almost here, so this may be my last
> flight in this glider, I'm just too tired of fixing it. Most likely it
> will go to a museum.

Dick's last flight in the Antares was a year ago:
https://www.onlinecontest.org/olc-3.0/gliding/flightbook.html?sp=2021&st=olcp&rt=olc&pi=32642
And he didn't fly it at all this year. I heard that he had to fly a tech out from Germany to fix the electronics in the 20E, but I could be mistaken. Also, he got an Arcus M, not a Ventus.

Tom

On 10/16/2021 8:59 PM, 2G wrote:
> On Saturday, October 16, 2021 at 4:10:53 AM UTC-7, waremark wrote:
>> Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.
>>
>> I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.
>>
>> Finally, that is an electric self launcher with an endurance greater than I have ever needed.
>>
>> If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?
>>
>> Mark Burton
>
> I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.
>
> Tom

This year Dick has flown his Antares only twice, but I don't know the reason for that.
Dick's OLC postings show he flew his Antares 71(!) times in 2020, 35 times in 2019, 26
times in 2018, and 40 times in 2017. That does not seem like such an unreliable glider to me.

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

On Sunday, October 17, 2021 at 8:53:13 AM UTC-7, Eric Greenwell wrote:
> On 10/16/2021 8:59 PM, 2G wrote:
> > On Saturday, October 16, 2021 at 4:10:53 AM UTC-7, waremark wrote:
> >> Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.
> >>
> >> I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.
> >>
> >> Finally, that is an electric self launcher with an endurance greater than I have ever needed.
> >>
> >> If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?
> >>
> >> Mark Burton
> >
> > I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.
> >
> > Tom
> This year Dick has flown his Antares only twice, but I don't know the reason for that.
> Dick's OLC postings show he flew his Antares 71(!) times in 2020, 35 times in 2019, 26
> times in 2018, and 40 times in 2017. That does not seem like such an unreliable glider to me.
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

So why did he switch to an Arcus M?

Tom

On 10/17/2021 10:25 AM, 2G wrote:
> On Sunday, October 17, 2021 at 8:53:13 AM UTC-7, Eric Greenwell wrote:
>> On 10/16/2021 8:59 PM, 2G wrote:
>>> On Saturday, October 16, 2021 at 4:10:53 AM UTC-7, waremark wrote:
>>>> Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.
>>>>
>>>> I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.
>>>>
>>>> Finally, that is an electric self launcher with an endurance greater than I have ever needed.
>>>>
>>>> If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?
>>>>
>>>> Mark Burton
>>>
>>> I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.
>>>
>>> Tom
>> This year Dick has flown his Antares only twice, but I don't know the reason for that.
>> Dick's OLC postings show he flew his Antares 71(!) times in 2020, 35 times in 2019, 26
>> times in 2018, and 40 times in 2017. That does not seem like such an unreliable glider to me.
>> --
>> Eric Greenwell - USA
>> - "A Guide to Self-launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
>
> So why did he switch to an Arcus M?

He flew the Arcus M and Antares in every year I mentioned, and also in 2016, 2015. The
Ventus 2cm, which he owned in 2007 (and maybe earlier), was flown till 2015, along with
the Antares, which appeared in 2009. So Ventus first, then Antares. In 2020, he flew the
Antares almost exclusively; in 2021, he's flown the Arcus almost exclusively. I don't
think these numbers are enough to gauge the reliability of either glider. He's flown the
Antares A LOT over over the years from 2009 to now!

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

On Sunday, 17 October 2021 at 06:33:31 UTC+1, kinsell wrote:
> On 10/16/21 10:48 PM, Michael Bamberg wrote:
> >

> Nadler (former U.S. dealer) had a really nice flight last spring, but
> put this in his posting:
>
>
> This is the 6th flight since 2020's extensive rework to engineer around
> assorted Lange design problems. And - today it had another failure
> (thermal fuse). The new glider is almost here, so this may be my last
> flight in this glider, I'm just too tired of fixing it. Most likely it
> will go to a museum.

Does anyone know what Dave Nadler means about the 2020 extensive rework, is that about work to his own glider or the development by Lange of the new model 21E?

Has anyone heard what new glider Dave Nadler is getting?

On Sunday, October 17, 2021 at 11:01:22 AM UTC-7, Eric Greenwell wrote:
> On 10/17/2021 10:25 AM, 2G wrote:
> > On Sunday, October 17, 2021 at 8:53:13 AM UTC-7, Eric Greenwell wrote:
> >> On 10/16/2021 8:59 PM, 2G wrote:
> >>> On Saturday, October 16, 2021 at 4:10:53 AM UTC-7, waremark wrote:
> >>>> Reviving this thread on the broader topic of electric ancillary power for gliders rather than specifically related to fire.
> >>>>
> >>>> I saw a recent YouTube video of a test flight of an Antares 21E and read about it on the Lange Aviation website. The website claims a climb potential with an optional larger battery of 5,600 m, a max climb rate of approx 900 fpm, sub 10 secs time from activation to climb (that was from the video), and 9 hours charge time for a full charge (on the video Lange says 3.5 hours to charge from 50%). I didn't see what the empty weight was with the larger battery, with the standard battery the stats suggested a wider range of wing loading in both directions than my Arcus M with two on board. Best glide was quoted at 58 to 1.
> >>>>
> >>>> Finally, that is an electric self launcher with an endurance greater than I have ever needed.
> >>>>
> >>>> If I could be persuaded that the fire risk and reliability are no worse than for an ICE powered self launcher, I would find the rest of the specs very persuasive. Does anyone know whether this glider is actually in production, and any more about it?
> >>>>
> >>>> Mark Burton
> >>>
> >>> I would hope that the 21E is more reliable than the 20E, which is horrible. The article mentions the name of Dick VanGrunsven who had so many problems with his 20E that he bought a Ventus. The promise of electric high reliability is just that: a promise.
> >>>
> >>> Tom
> >> This year Dick has flown his Antares only twice, but I don't know the reason for that.
> >> Dick's OLC postings show he flew his Antares 71(!) times in 2020, 35 times in 2019, 26
> >> times in 2018, and 40 times in 2017. That does not seem like such an unreliable glider to me.
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
> >
> > So why did he switch to an Arcus M?
> He flew the Arcus M and Antares in every year I mentioned, and also in 2016, 2015. The
> Ventus 2cm, which he owned in 2007 (and maybe earlier), was flown till 2015, along with
> the Antares, which appeared in 2009. So Ventus first, then Antares. In 2020, he flew the
> Antares almost exclusively; in 2021, he's flown the Arcus almost exclusively. I don't
> think these numbers are enough to gauge the reliability of either glider. He's flown the
> Antares A LOT over over the years from 2009 to now!
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

That does not mean that the glider was problem free.

Tom

On 10/17/21 3:41 PM, waremark wrote:
> On Sunday, 17 October 2021 at 06:33:31 UTC+1, kinsell wrote:
>> On 10/16/21 10:48 PM, Michael Bamberg wrote:
>>>
>
>> Nadler (former U.S. dealer) had a really nice flight last spring, but
>> put this in his posting:
>>
>>
>> This is the 6th flight since 2020's extensive rework to engineer around
>> assorted Lange design problems. And - today it had another failure
>> (thermal fuse). The new glider is almost here, so this may be my last
>> flight in this glider, I'm just too tired of fixing it. Most likely it
>> will go to a museum.
>
> Does anyone know what Dave Nadler means about the 2020 extensive rework, is that about work to his own glider or the development by Lange of the new model 21E?
>
> Has anyone heard what new glider Dave Nadler is getting?
>

From the context, I'm sure he was talking about trying to fix problems
on his own personal glider. Is Lange claiming to do major redesign on
the 21E, or is it just bigger batteries and and longer tips? Maybe it's
just putting lipstick on the pig, with a new marketing push?