On 4/4/2022 4:58 PM, 2G wrote:
> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
>> with the bigger wing and the option for using a personal parachute. Since I think the
>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
>> order the optional motor controller fire suppression system.
>>
>> A fire suppression option is also available for the wing mounted batteries, and I am
>> considering ordering that system, too.
>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
>>> ...And I have plans in place for the unfortunate eventually.
....
>> --
>> Eric Greenwell - USA
>> - "A Guide to Self-launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications
>
> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
>
> Tom
My main concern is electronic motor controller, for which there are several types of fire
suppression systems. I don't have the details of that system or the battery fire
suppression system, so I can't describe either of them, nor do I what "fire" they will be
trying to suppress in the wing where the batteries are mounted. It may be a structure
fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
that would give the pilot time to descend and land normally, or deploy the parachute at
about 1000' AGL, from where he can be on the ground in less than a minute.

Before I order either system, I'll have the complete details to guide my decision.

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

On 4/4/2022 7:52 PM, kinsell wrote:
> On 4/4/22 20:31, Dave Nadler wrote:
>> On 4/4/2022 8:06 PM, 2G wrote:
>>> The model Schleicher that caught fire was a 26e, which I don't fly anymore (I own a 31Mi).
>>
>> Um, what about the 25 fires??
>> One happened to a friend of mine.
>> Original cooling shroud material was flammable (replaced by metal)...
>
> "replaced" is too a strong a word.  The carbon fiber shrouds have never been subject to
> mandatory replacement, although the mufflers have been.
>
> But of course a company that makes mistakes like that couldn't possibly screw up a complex
> electric system.
Schleicher isn't the designer of their propulsion system electronics.

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

On Monday, April 4, 2022 at 7:56:18 PM UTC-7, Eric Greenwell wrote:
> On 4/4/2022 4:58 PM, 2G wrote:
> > On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> >> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> >> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> >> with the bigger wing and the option for using a personal parachute. Since I think the
> >> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> >> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> >> order the optional motor controller fire suppression system.
> >>
> >> A fire suppression option is also available for the wing mounted batteries, and I am
> >> considering ordering that system, too.
> >> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> >>> ...And I have plans in place for the unfortunate eventually.
> ...
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications
> >
> > Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> >
> > Tom
> My main concern is electronic motor controller, for which there are several types of fire
> suppression systems. I don't have the details of that system or the battery fire
> suppression system, so I can't describe either of them, nor do I what "fire" they will be
> trying to suppress in the wing where the batteries are mounted. It may be a structure
> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> that would give the pilot time to descend and land normally, or deploy the parachute at
> about 1000' AGL, from where he can be on the ground in less than a minute..
>
> Before I order either system, I'll have the complete details to guide my decision.
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications

I would not be concerned about the motor controller - it doesn't have any fuel source that can burn, but generates heat only as long as an energy source (electrical current) is supplied. Interrupt the current and the "fire" stops. That is what fuses are for.

Ten minutes wasn't available to the Taurus Electro pilot - he was incapacitated in seconds.

Tom

On 4/4/22 20:59, Eric Greenwell wrote:
> On 4/4/2022 7:52 PM, kinsell wrote:
>> On 4/4/22 20:31, Dave Nadler wrote:
>>> On 4/4/2022 8:06 PM, 2G wrote:
>>>> The model Schleicher that caught fire was a 26e, which I don't fly
>>>> anymore (I own a 31Mi).
>>>
>>> Um, what about the 25 fires??
>>> One happened to a friend of mine.
>>> Original cooling shroud material was flammable (replaced by metal)...
>>
>> "replaced" is too a strong a word.  The carbon fiber shrouds have
>> never been subject to mandatory replacement, although the mufflers
>> have been.
>>
>> But of course a company that makes mistakes like that couldn't
>> possibly screw up a complex electric system.
> Schleicher isn't the designer of their propulsion system electronics.
>

Neither is GP, but they managed to deliver their first glider with a
miswired motor that burned out after 10 minutes of running on the
ground. The second one wasn't much better.

On 4/4/2022 8:04 PM, 2G wrote:
> On Monday, April 4, 2022 at 7:56:18 PM UTC-7, Eric Greenwell wrote:
>> On 4/4/2022 4:58 PM, 2G wrote:
>>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
>>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
>>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
>>>> with the bigger wing and the option for using a personal parachute. Since I think the
>>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
>>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
>>>> order the optional motor controller fire suppression system.
>>>>
>>>> A fire suppression option is also available for the wing mounted batteries, and I am
>>>> considering ordering that system, too.
>>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
>>>>> ...And I have plans in place for the unfortunate eventually.
>> ...
>>>> --
>>>> Eric Greenwell - USA
>>>> - "A Guide to Self-launching Sailplane Operation"
>>>> https://sites.google.com/site/motorgliders/publications
>>>
>>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
>>>
>>> Tom
>> My main concern is electronic motor controller, for which there are several types of fire
>> suppression systems. I don't have the details of that system or the battery fire
>> suppression system, so I can't describe either of them, nor do I what "fire" they will be
>> trying to suppress in the wing where the batteries are mounted. It may be a structure
>> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
>> that would give the pilot time to descend and land normally, or deploy the parachute at
>> about 1000' AGL, from where he can be on the ground in less than a minute.
>>
>> Before I order either system, I'll have the complete details to guide my decision.
>> --
>> Eric Greenwell - USA
>> - "A Guide to Self-launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications
>
> I would not be concerned about the motor controller - it doesn't have any fuel source that can burn, but generates heat only as long as an energy source (electrical current) is supplied. Interrupt the current and the "fire" stops. That is what fuses are for.
>
> Ten minutes wasn't available to the Taurus Electro pilot - he was incapacitated in seconds.
>
> Tom
That Taurus is a very different design than the Jetta, and was not as safe (in my
estimation), for these reasons (and others):
- The batteries were in the fuselage, instead of the wing like the Jeta
- the batteries were foil pouches; the Jeta uses cells that are manufactured with a metal
container
- the Taurus batteries were routinely removed and potentially subjected to dropping

Even so, I believe the changes made since that fire substantially improved the safety of
the Taurus, and I'd willing fly it.

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

On Monday, April 4, 2022 at 9:31:11 PM UTC-7, Eric Greenwell wrote:
> On 4/4/2022 8:04 PM, 2G wrote:
> > On Monday, April 4, 2022 at 7:56:18 PM UTC-7, Eric Greenwell wrote:
> >> On 4/4/2022 4:58 PM, 2G wrote:
> >>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> >>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> >>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> >>>> with the bigger wing and the option for using a personal parachute. Since I think the
> >>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> >>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> >>>> order the optional motor controller fire suppression system.
> >>>>
> >>>> A fire suppression option is also available for the wing mounted batteries, and I am
> >>>> considering ordering that system, too.
> >>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> >>>>> ...And I have plans in place for the unfortunate eventually.
> >> ...
> >>>> --
> >>>> Eric Greenwell - USA
> >>>> - "A Guide to Self-launching Sailplane Operation"
> >>>> https://sites.google.com/site/motorgliders/publications
> >>>
> >>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> >>>
> >>> Tom
> >> My main concern is electronic motor controller, for which there are several types of fire
> >> suppression systems. I don't have the details of that system or the battery fire
> >> suppression system, so I can't describe either of them, nor do I what "fire" they will be
> >> trying to suppress in the wing where the batteries are mounted. It may be a structure
> >> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> >> that would give the pilot time to descend and land normally, or deploy the parachute at
> >> about 1000' AGL, from where he can be on the ground in less than a minute.
> >>
> >> Before I order either system, I'll have the complete details to guide my decision.
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications
> >
> > I would not be concerned about the motor controller - it doesn't have any fuel source that can burn, but generates heat only as long as an energy source (electrical current) is supplied. Interrupt the current and the "fire" stops. That is what fuses are for.
> >
> > Ten minutes wasn't available to the Taurus Electro pilot - he was incapacitated in seconds.
> >
> > Tom
> That Taurus is a very different design than the Jetta, and was not as safe (in my
> estimation), for these reasons (and others):
> - The batteries were in the fuselage, instead of the wing like the Jeta
> - the batteries were foil pouches; the Jeta uses cells that are manufactured with a metal
> container
> - the Taurus batteries were routinely removed and potentially subjected to dropping
>
> Even so, I believe the changes made since that fire substantially improved the safety of
> the Taurus, and I'd willing fly it.
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications

One shouldn't immediately assume that cylindrical cells are safer than pouch cells. Besides the Tesla fire database I previously cited, here is Tesla battery farm fire in Australia:
https://www.cnbc.com/2021/07/30/tesla-megapack-caught-fire-at-victorian-big-battery-site-in-australia.html
https://stopthesethings.com/2021/07/31/battery-bombs-more-giant-renewable-energy-batteries-explode-in-toxic-fireballs/
Tesla batteries, of course, use cylindrical cells, and are in a controlled, non-vibration environment. In other words, battery farms should be the LEAST LIKELY environment for a battery fire. Aircraft are subject to repeated positive and negative g-loading as well as significant vibration while flown in turbulent air.

Placing the batteries in the wings may position them modestly further away from the pilot than the fuselage, but does it prevent fire fumes from reaching the pilot? In any event, a major fire in the wing(s) is a very serious situation, and would probably compromise the BRS.

Tom

On Monday, April 4, 2022 at 10:56:18 PM UTC-4, Eric Greenwell wrote:
> On 4/4/2022 4:58 PM, 2G wrote:
> > On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> >> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> >> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> >> with the bigger wing and the option for using a personal parachute. Since I think the
> >> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> >> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> >> order the optional motor controller fire suppression system.
> >>
> >> A fire suppression option is also available for the wing mounted batteries, and I am
> >> considering ordering that system, too.
> >> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> >>> ...And I have plans in place for the unfortunate eventually.
> ...
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications
> >
> > Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> >
> > Tom
> My main concern is electronic motor controller, for which there are several types of fire
> suppression systems. I don't have the details of that system or the battery fire
> suppression system, so I can't describe either of them, nor do I what "fire" they will be
> trying to suppress in the wing where the batteries are mounted. It may be a structure
> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> that would give the pilot time to descend and land normally, or deploy the parachute at
> about 1000' AGL, from where he can be on the ground in less than a minute..
>
> Before I order either system, I'll have the complete details to guide my decision.
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications

The MGM HBC series controllers that were being used(not sure if they still are), can have a nasty electrical fire if there is a short between board layers. I know this from first hand experience. The fire stops as soon as power is removed. Very stinky.
FWIW
UH

On Tuesday, April 5, 2022 at 9:10:51 AM UTC-7, Hank Nixon wrote:
> On Monday, April 4, 2022 at 10:56:18 PM UTC-4, Eric Greenwell wrote:
> > On 4/4/2022 4:58 PM, 2G wrote:
> > > On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> > >> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> > >> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> > >> with the bigger wing and the option for using a personal parachute. Since I think the
> > >> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> > >> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> > >> order the optional motor controller fire suppression system.
> > >>
> > >> A fire suppression option is also available for the wing mounted batteries, and I am
> > >> considering ordering that system, too.
> > >> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> > >>> ...And I have plans in place for the unfortunate eventually.
> > ...
> > >> --
> > >> Eric Greenwell - USA
> > >> - "A Guide to Self-launching Sailplane Operation"
> > >> https://sites.google.com/site/motorgliders/publications
> > >
> > > Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> > >
> > > Tom
> > My main concern is electronic motor controller, for which there are several types of fire
> > suppression systems. I don't have the details of that system or the battery fire
> > suppression system, so I can't describe either of them, nor do I what "fire" they will be
> > trying to suppress in the wing where the batteries are mounted. It may be a structure
> > fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> > that would give the pilot time to descend and land normally, or deploy the parachute at
> > about 1000' AGL, from where he can be on the ground in less than a minute.
> >
> > Before I order either system, I'll have the complete details to guide my decision.
> > --
> > Eric Greenwell - USA
> > - "A Guide to Self-launching Sailplane Operation"
> > https://sites.google.com/site/motorgliders/publications
> The MGM HBC series controllers that were being used(not sure if they still are), can have a nasty electrical fire if there is a short between board layers. I know this from first hand experience. The fire stops as soon as power is removed. Very stinky.
> FWIW
> UH

Again, manageable by fusing.

Tom

On Wednesday, April 6, 2022 at 12:54:23 AM UTC-4, 2G wrote:
> On Tuesday, April 5, 2022 at 9:10:51 AM UTC-7, Hank Nixon wrote:
> > On Monday, April 4, 2022 at 10:56:18 PM UTC-4, Eric Greenwell wrote:
> > > On 4/4/2022 4:58 PM, 2G wrote:
> > > > On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> > > >> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> > > >> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> > > >> with the bigger wing and the option for using a personal parachute.. Since I think the
> > > >> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> > > >> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> > > >> order the optional motor controller fire suppression system.
> > > >>
> > > >> A fire suppression option is also available for the wing mounted batteries, and I am
> > > >> considering ordering that system, too.
> > > >> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> > > >>> ...And I have plans in place for the unfortunate eventually.
> > > ...
> > > >> --
> > > >> Eric Greenwell - USA
> > > >> - "A Guide to Self-launching Sailplane Operation"
> > > >> https://sites.google.com/site/motorgliders/publications
> > > >
> > > > Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> > > >
> > > > Tom
> > > My main concern is electronic motor controller, for which there are several types of fire
> > > suppression systems. I don't have the details of that system or the battery fire
> > > suppression system, so I can't describe either of them, nor do I what "fire" they will be
> > > trying to suppress in the wing where the batteries are mounted. It may be a structure
> > > fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> > > that would give the pilot time to descend and land normally, or deploy the parachute at
> > > about 1000' AGL, from where he can be on the ground in less than a minute.
> > >
> > > Before I order either system, I'll have the complete details to guide my decision.
> > > --
> > > Eric Greenwell - USA
> > > - "A Guide to Self-launching Sailplane Operation"
> > > https://sites.google.com/site/motorgliders/publications
> > The MGM HBC series controllers that were being used(not sure if they still are), can have a nasty electrical fire if there is a short between board layers. I know this from first hand experience. The fire stops as soon as power is removed. Very stinky.
> > FWIW
> > UH
> Again, manageable by fusing.
>
> Tom
The normal max operating current in my system is about 250 amps. I'm fused at 300. You can make a pretty impressive fire within normal operating current. Opening the main contactor breaks the circuit immediately.
But what do I know
UH

On 4/5/22 10:10, Hank Nixon wrote:
> On Monday, April 4, 2022 at 10:56:18 PM UTC-4, Eric Greenwell wrote:
>> On 4/4/2022 4:58 PM, 2G wrote:
>>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
>>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
>>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
>>>> with the bigger wing and the option for using a personal parachute. Since I think the
>>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
>>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
>>>> order the optional motor controller fire suppression system.
>>>>
>>>> A fire suppression option is also available for the wing mounted batteries, and I am
>>>> considering ordering that system, too.
>>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
>>>>> ...And I have plans in place for the unfortunate eventually.
>> ...
>>>> --
>>>> Eric Greenwell - USA
>>>> - "A Guide to Self-launching Sailplane Operation"
>>>> https://sites.google.com/site/motorgliders/publications
>>>
>>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
>>>
>>> Tom
>> My main concern is electronic motor controller, for which there are several types of fire
>> suppression systems. I don't have the details of that system or the battery fire
>> suppression system, so I can't describe either of them, nor do I what "fire" they will be
>> trying to suppress in the wing where the batteries are mounted. It may be a structure
>> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
>> that would give the pilot time to descend and land normally, or deploy the parachute at
>> about 1000' AGL, from where he can be on the ground in less than a minute.
>>
>> Before I order either system, I'll have the complete details to guide my decision.
>> --
>> Eric Greenwell - USA
>> - "A Guide to Self-launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications
>
> The MGM HBC series controllers that were being used(not sure if they still are), can have a nasty electrical fire if there is a short between board layers. I know this from first hand experience. The fire stops as soon as power is removed. Very stinky.
> FWIW
> UH

That's weird. MGM-Compro is sposed to be a world leader in electrical
propulsion systems. If those guys can screw up, how are we going to get
fool-proof zero maintenance ultra reliable electric motor gliders??

On Wednesday, April 6, 2022 at 9:23:06 AM UTC-4, kinsell wrote:
> On 4/5/22 10:10, Hank Nixon wrote:
> > On Monday, April 4, 2022 at 10:56:18 PM UTC-4, Eric Greenwell wrote:
> >> On 4/4/2022 4:58 PM, 2G wrote:
> >>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> >>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> >>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> >>>> with the bigger wing and the option for using a personal parachute. Since I think the
> >>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> >>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> >>>> order the optional motor controller fire suppression system.
> >>>>
> >>>> A fire suppression option is also available for the wing mounted batteries, and I am
> >>>> considering ordering that system, too.
> >>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> >>>>> ...And I have plans in place for the unfortunate eventually.
> >> ...
> >>>> --
> >>>> Eric Greenwell - USA
> >>>> - "A Guide to Self-launching Sailplane Operation"
> >>>> https://sites.google.com/site/motorgliders/publications
> >>>
> >>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> >>>
> >>> Tom
> >> My main concern is electronic motor controller, for which there are several types of fire
> >> suppression systems. I don't have the details of that system or the battery fire
> >> suppression system, so I can't describe either of them, nor do I what "fire" they will be
> >> trying to suppress in the wing where the batteries are mounted. It may be a structure
> >> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> >> that would give the pilot time to descend and land normally, or deploy the parachute at
> >> about 1000' AGL, from where he can be on the ground in less than a minute.
> >>
> >> Before I order either system, I'll have the complete details to guide my decision.
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications
> >
> > The MGM HBC series controllers that were being used(not sure if they still are), can have a nasty electrical fire if there is a short between board layers. I know this from first hand experience. The fire stops as soon as power is removed. Very stinky.
> > FWIW
> > UH
> That's weird. MGM-Compro is sposed to be a world leader in electrical
> propulsion systems. If those guys can screw up, how are we going to get
> fool-proof zero maintenance ultra reliable electric motor gliders??

More to the story. There was no indication in their documentation that proximity of metal to the edge of their boards would be an issue. In fact they implied it was not. I stupidly took them at their word and made my mounts out of sheet aluminum because it was quick and easy. Part way through testing, outside the ship , there was a short and a fire. $2500 mistake. The next mounts were fiberglass. You can't buy experience, but you do pay for it. I use another brand of controller now.
UH

On 4/6/2022 6:23 AM, kinsell wrote:
>> The MGM HBC series controllers that were being used(not sure if they still are), can
>> have a nasty electrical fire if there is a short between board layers. I know this from
>> first hand experience. The fire stops as soon as power is removed. Very stinky.
>> FWIW
>> UH
>
> That's weird.  MGM-Compro is sposed to be a world leader in electrical propulsion
> systems.  If those guys can screw up, how are we going to get fool-proof zero maintenance
> ultra reliable electric motor gliders??

I have good news for you: we have that glider already! And, it uses an FES propulsion.
Talk to FES owners, monitor their news groups, and you'll discover what I did: the owners
are very happy, and the news groups have very little conversation. Why is that? One dealer
summed it up this way: "What's to talk about? You charge it, you fly it, repeat as desired."

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

On 4/6/2022 6:23 AM, kinsell wrote:

>
> That's weird.  MGM-Compro is sposed to be a world leader in electrical propulsion
> systems.  If those guys can screw up, how are we going to get fool-proof zero maintenance
> ultra reliable electric motor gliders??

I've started another thread for this subject: "fool-proof zero maintenance ultra reliable
electric motor gliders"

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

On 4/5/2022 8:37 AM, 2G wrote:
> On Monday, April 4, 2022 at 9:31:11 PM UTC-7, Eric Greenwell wrote:
>> On 4/4/2022 8:04 PM, 2G wrote:
>>> On Monday, April 4, 2022 at 7:56:18 PM UTC-7, Eric Greenwell wrote:
>>>> On 4/4/2022 4:58 PM, 2G wrote:
>>>>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
>>>>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
>>>>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
>>>>>> with the bigger wing and the option for using a personal parachute. Since I think the
>>>>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
>>>>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
>>>>>> order the optional motor controller fire suppression system.
>>>>>>
>>>>>> A fire suppression option is also available for the wing mounted batteries, and I am
>>>>>> considering ordering that system, too.
>>>>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
>>>>>>> ...And I have plans in place for the unfortunate eventually.
>>>> ...
>>>>>> --
>>>>>> Eric Greenwell - USA
>>>>>> - "A Guide to Self-launching Sailplane Operation"
>>>>>> https://sites.google.com/site/motorgliders/publications
>>>>>
>>>>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
>>>>>
>>>>> Tom
>>>> My main concern is electronic motor controller, for which there are several types of fire
>>>> suppression systems. I don't have the details of that system or the battery fire
>>>> suppression system, so I can't describe either of them, nor do I what "fire" they will be
>>>> trying to suppress in the wing where the batteries are mounted. It may be a structure
>>>> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
>>>> that would give the pilot time to descend and land normally, or deploy the parachute at
>>>> about 1000' AGL, from where he can be on the ground in less than a minute.
>>>>
>>>> Before I order either system, I'll have the complete details to guide my decision.
>>>> --
>>>> Eric Greenwell - USA
>>>> - "A Guide to Self-launching Sailplane Operation"
>>>> https://sites.google.com/site/motorgliders/publications
>>>
>>> I would not be concerned about the motor controller - it doesn't have any fuel source that can burn, but generates heat only as long as an energy source (electrical current) is supplied. Interrupt the current and the "fire" stops. That is what fuses are for.
>>>
>>> Ten minutes wasn't available to the Taurus Electro pilot - he was incapacitated in seconds.
>>>
>>> Tom
>> That Taurus is a very different design than the Jetta, and was not as safe (in my
>> estimation), for these reasons (and others):
>> - The batteries were in the fuselage, instead of the wing like the Jeta
>> - the batteries were foil pouches; the Jeta uses cells that are manufactured with a metal
>> container
>> - the Taurus batteries were routinely removed and potentially subjected to dropping
>>
>> Even so, I believe the changes made since that fire substantially improved the safety of
>> the Taurus, and I'd willing fly it.
>> --
>> Eric Greenwell - USA
>> - "A Guide to Self-launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications
>
> One shouldn't immediately assume that cylindrical cells are safer than pouch cells. Besides the Tesla fire database I previously cited, here is Tesla battery farm fire in Australia:
> https://www.cnbc.com/2021/07/30/tesla-megapack-caught-fire-at-victorian-big-battery-site-in-australia.html
> https://stopthesethings.com/2021/07/31/battery-bombs-more-giant-renewable-energy-batteries-explode-in-toxic-fireballs/
> Tesla batteries, of course, use cylindrical cells, and are in a controlled, non-vibration environment. In other words, battery farms should be the LEAST LIKELY environment for a battery fire. Aircraft are subject to repeated positive and negative g-loading as well as significant vibration while flown in turbulent air.
>
> Placing the batteries in the wings may position them modestly further away from the pilot than the fuselage, but does it prevent fire fumes from reaching the pilot? In any event, a major fire in the wing(s) is a very serious situation, and would probably compromise the BRS.
>
> Tom
I was speaking specifically about the Taurus situation. After that accident, there were
major changes in design and manufacturing, and EASA regulations, that likely make pouch
and cylindrical systems much closer in safety.

A major fire anywhere on an aircraft is a very serious situation! Obviously, the
manufacturers know this, and design the battery pack and it's installation reduce the
risk. For example, the wing roots are sealed to prevent fumes from entering the fuselage,
and venting is used to discharge the fumes from the wing. This shows a fume vent on the
Antares:

https://nordicgliding-com.translate.goog/opdateret-lange-antares-faar-tesla-batterier/?_x_tr_sl=da&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui

Scroll down about half way to "Great demands on security".

Vibration and G loads while operating a glider isn't a problem for the cylindrical cells,
as they are very sturdy. Look up the specs for a typical 16850 cell, such as the
Sony/Murata VCT6 cells used in the Jeta.

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

On Wednesday, April 6, 2022 at 11:15:22 PM UTC-4, Eric Greenwell wrote:
> On 4/6/2022 6:23 AM, kinsell wrote:
> >> The MGM HBC series controllers that were being used(not sure if they still are), can
> >> have a nasty electrical fire if there is a short between board layers. I know this from
> >> first hand experience. The fire stops as soon as power is removed. Very stinky.
> >> FWIW
> >> UH
> >
> > That's weird. MGM-Compro is sposed to be a world leader in electrical propulsion
> > systems. If those guys can screw up, how are we going to get fool-proof zero maintenance
> > ultra reliable electric motor gliders??
> I have good news for you: we have that glider already! And, it uses an FES propulsion.
> Talk to FES owners, monitor their news groups, and you'll discover what I did: the owners
> are very happy, and the news groups have very little conversation. Why is that? One dealer
> summed it up this way: "What's to talk about? You charge it, you fly it, repeat as desired."
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications

I'm using the same controller that the FES gliders use. After troubles with the HBC controller I researched and identified the controller in the FES ships and migrated to that. Once integration issues were resolved it has worked very well. '24EL uses Sony VT6C cells . '25EL uses Samsung INR 25R due to lack of availability of VT6C cells.
UH

On Wednesday, April 6, 2022 at 8:38:18 PM UTC-7, Eric Greenwell wrote:
> On 4/5/2022 8:37 AM, 2G wrote:
> > On Monday, April 4, 2022 at 9:31:11 PM UTC-7, Eric Greenwell wrote:
> >> On 4/4/2022 8:04 PM, 2G wrote:
> >>> On Monday, April 4, 2022 at 7:56:18 PM UTC-7, Eric Greenwell wrote:
> >>>> On 4/4/2022 4:58 PM, 2G wrote:
> >>>>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> >>>>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> >>>>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> >>>>>> with the bigger wing and the option for using a personal parachute.. Since I think the
> >>>>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> >>>>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> >>>>>> order the optional motor controller fire suppression system.
> >>>>>>
> >>>>>> A fire suppression option is also available for the wing mounted batteries, and I am
> >>>>>> considering ordering that system, too.
> >>>>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> >>>>>>> ...And I have plans in place for the unfortunate eventually.
> >>>> ...
> >>>>>> --
> >>>>>> Eric Greenwell - USA
> >>>>>> - "A Guide to Self-launching Sailplane Operation"
> >>>>>> https://sites.google.com/site/motorgliders/publications
> >>>>>
> >>>>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> >>>>>
> >>>>> Tom
> >>>> My main concern is electronic motor controller, for which there are several types of fire
> >>>> suppression systems. I don't have the details of that system or the battery fire
> >>>> suppression system, so I can't describe either of them, nor do I what "fire" they will be
> >>>> trying to suppress in the wing where the batteries are mounted. It may be a structure
> >>>> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> >>>> that would give the pilot time to descend and land normally, or deploy the parachute at
> >>>> about 1000' AGL, from where he can be on the ground in less than a minute.
> >>>>
> >>>> Before I order either system, I'll have the complete details to guide my decision.
> >>>> --
> >>>> Eric Greenwell - USA
> >>>> - "A Guide to Self-launching Sailplane Operation"
> >>>> https://sites.google.com/site/motorgliders/publications
> >>>
> >>> I would not be concerned about the motor controller - it doesn't have any fuel source that can burn, but generates heat only as long as an energy source (electrical current) is supplied. Interrupt the current and the "fire" stops. That is what fuses are for.
> >>>
> >>> Ten minutes wasn't available to the Taurus Electro pilot - he was incapacitated in seconds.
> >>>
> >>> Tom
> >> That Taurus is a very different design than the Jetta, and was not as safe (in my
> >> estimation), for these reasons (and others):
> >> - The batteries were in the fuselage, instead of the wing like the Jeta
> >> - the batteries were foil pouches; the Jeta uses cells that are manufactured with a metal
> >> container
> >> - the Taurus batteries were routinely removed and potentially subjected to dropping
> >>
> >> Even so, I believe the changes made since that fire substantially improved the safety of
> >> the Taurus, and I'd willing fly it.
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications
> >
> > One shouldn't immediately assume that cylindrical cells are safer than pouch cells. Besides the Tesla fire database I previously cited, here is Tesla battery farm fire in Australia:
> > https://www.cnbc.com/2021/07/30/tesla-megapack-caught-fire-at-victorian-big-battery-site-in-australia.html
> > https://stopthesethings.com/2021/07/31/battery-bombs-more-giant-renewable-energy-batteries-explode-in-toxic-fireballs/
> > Tesla batteries, of course, use cylindrical cells, and are in a controlled, non-vibration environment. In other words, battery farms should be the LEAST LIKELY environment for a battery fire. Aircraft are subject to repeated positive and negative g-loading as well as significant vibration while flown in turbulent air.
> >
> > Placing the batteries in the wings may position them modestly further away from the pilot than the fuselage, but does it prevent fire fumes from reaching the pilot? In any event, a major fire in the wing(s) is a very serious situation, and would probably compromise the BRS.
> >
> > Tom
> I was speaking specifically about the Taurus situation. After that accident, there were
> major changes in design and manufacturing, and EASA regulations, that likely make pouch
> and cylindrical systems much closer in safety.
>
> A major fire anywhere on an aircraft is a very serious situation! Obviously, the
> manufacturers know this, and design the battery pack and it's installation reduce the
> risk. For example, the wing roots are sealed to prevent fumes from entering the fuselage,
> and venting is used to discharge the fumes from the wing. This shows a fume vent on the
> Antares:
>
> https://nordicgliding-com.translate.goog/opdateret-lange-antares-faar-tesla-batterier/?_x_tr_sl=da&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui
>
> Scroll down about half way to "Great demands on security".
>
> Vibration and G loads while operating a glider isn't a problem for the cylindrical cells,
> as they are very sturdy. Look up the specs for a typical 16850 cell, such as the
> Sony/Murata VCT6 cells used in the Jeta.

This is a statement devoid of evidence. I, on the other hand, presented PLENTY of evidence to the contrary.

Tom

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

Tom, were those Tesla walls using LiFePo4 cells, or some other chemistry? Pretty sure you already know the answer to that....
On Tuesday, April 5, 2022 at 8:37:20 AM UTC-7, 2G wrote:
> On Monday, April 4, 2022 at 9:31:11 PM UTC-7, Eric Greenwell wrote:
> > On 4/4/2022 8:04 PM, 2G wrote:
> > > On Monday, April 4, 2022 at 7:56:18 PM UTC-7, Eric Greenwell wrote:
> > >> On 4/4/2022 4:58 PM, 2G wrote:
> > >>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> > >>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> > >>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> > >>>> with the bigger wing and the option for using a personal parachute.. Since I think the
> > >>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> > >>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> > >>>> order the optional motor controller fire suppression system.
> > >>>>
> > >>>> A fire suppression option is also available for the wing mounted batteries, and I am
> > >>>> considering ordering that system, too.
> > >>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> > >>>>> ...And I have plans in place for the unfortunate eventually.
> > >> ...
> > >>>> --
> > >>>> Eric Greenwell - USA
> > >>>> - "A Guide to Self-launching Sailplane Operation"
> > >>>> https://sites.google.com/site/motorgliders/publications
> > >>>
> > >>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> > >>>
> > >>> Tom
> > >> My main concern is electronic motor controller, for which there are several types of fire
> > >> suppression systems. I don't have the details of that system or the battery fire
> > >> suppression system, so I can't describe either of them, nor do I what "fire" they will be
> > >> trying to suppress in the wing where the batteries are mounted. It may be a structure
> > >> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> > >> that would give the pilot time to descend and land normally, or deploy the parachute at
> > >> about 1000' AGL, from where he can be on the ground in less than a minute.
> > >>
> > >> Before I order either system, I'll have the complete details to guide my decision.
> > >> --
> > >> Eric Greenwell - USA
> > >> - "A Guide to Self-launching Sailplane Operation"
> > >> https://sites.google.com/site/motorgliders/publications
> > >
> > > I would not be concerned about the motor controller - it doesn't have any fuel source that can burn, but generates heat only as long as an energy source (electrical current) is supplied. Interrupt the current and the "fire" stops. That is what fuses are for.
> > >
> > > Ten minutes wasn't available to the Taurus Electro pilot - he was incapacitated in seconds.
> > >
> > > Tom
> > That Taurus is a very different design than the Jetta, and was not as safe (in my
> > estimation), for these reasons (and others):
> > - The batteries were in the fuselage, instead of the wing like the Jeta
> > - the batteries were foil pouches; the Jeta uses cells that are manufactured with a metal
> > container
> > - the Taurus batteries were routinely removed and potentially subjected to dropping
> >
> > Even so, I believe the changes made since that fire substantially improved the safety of
> > the Taurus, and I'd willing fly it.
> > --
> > Eric Greenwell - USA
> > - "A Guide to Self-launching Sailplane Operation"
> > https://sites.google.com/site/motorgliders/publications
> One shouldn't immediately assume that cylindrical cells are safer than pouch cells. Besides the Tesla fire database I previously cited, here is Tesla battery farm fire in Australia:
> https://www.cnbc.com/2021/07/30/tesla-megapack-caught-fire-at-victorian-big-battery-site-in-australia.html
> https://stopthesethings.com/2021/07/31/battery-bombs-more-giant-renewable-energy-batteries-explode-in-toxic-fireballs/
> Tesla batteries, of course, use cylindrical cells, and are in a controlled, non-vibration environment. In other words, battery farms should be the LEAST LIKELY environment for a battery fire. Aircraft are subject to repeated positive and negative g-loading as well as significant vibration while flown in turbulent air.
>
> Placing the batteries in the wings may position them modestly further away from the pilot than the fuselage, but does it prevent fire fumes from reaching the pilot? In any event, a major fire in the wing(s) is a very serious situation, and would probably compromise the BRS.
>
> Tom

On 4/7/2022 9:49 PM, 2G wrote:
> On Wednesday, April 6, 2022 at 8:38:18 PM UTC-7, Eric Greenwell wrote:
....
>> I was speaking specifically about the Taurus situation. After that accident, there were
>> major changes in design and manufacturing, and EASA regulations, that likely make pouch
>> and cylindrical systems much closer in safety.
>>
>> A major fire anywhere on an aircraft is a very serious situation! Obviously, the
>> manufacturers know this, and design the battery pack and it's installation reduce the
>> risk. For example, the wing roots are sealed to prevent fumes from entering the fuselage,
>> and venting is used to discharge the fumes from the wing. This shows a fume vent on the
>> Antares:
>>
>> https://nordicgliding-com.translate.goog/opdateret-lange-antares-faar-tesla-batterier/?_x_tr_sl=da&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui
>>
>> Scroll down about half way to "Great demands on security".
>>
>> Vibration and G loads while operating a glider isn't a problem for the cylindrical cells,
>> as they are very sturdy. Look up the specs for a typical 16850 cell, such as the
>> Sony/Murata VCT6 cells used in the Jeta.
>
> This is a statement devoid of evidence. I, on the other hand, presented PLENTY of evidence to the contrary.
>
> Tom

18650 cells are used by the military, NASA rockets them into space, and EASA and others
allow their use in aircraft. So please, take the time to look up the physical specs
(vibration, etc) on the VCT6 cells, or pretty much any 18650 cell of the same chemistry.
Those are the ones used in gliders. Once you have those specs, you can compare the specs
to the loads those batteries experience in glider use. That's the evidence you need to
show us if you want to persuade anyone a glider is a "rough ride"!
--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications

On Friday, April 8, 2022 at 6:36:54 AM UTC-7, jfitch wrote:
> Tom, were those Tesla walls using LiFePo4 cells, or some other chemistry? Pretty sure you already know the answer to that....
> On Tuesday, April 5, 2022 at 8:37:20 AM UTC-7, 2G wrote:
> > On Monday, April 4, 2022 at 9:31:11 PM UTC-7, Eric Greenwell wrote:
> > > On 4/4/2022 8:04 PM, 2G wrote:
> > > > On Monday, April 4, 2022 at 7:56:18 PM UTC-7, Eric Greenwell wrote:
> > > >> On 4/4/2022 4:58 PM, 2G wrote:
> > > >>> On Monday, April 4, 2022 at 11:34:02 AM UTC-7, Eric Greenwell wrote:
> > > >>>> My Jeta will not have room for a personal parachute, or a canopy that can be ejected, as
> > > >>>> it would delay delivery significantly. Jetas built after mine will be the Jeta+ versions
> > > >>>> with the bigger wing and the option for using a personal parachute. Since I think the
> > > >>>> biggest fire risk is a fire caused by the failure of the motor controller electronics,
> > > >>>> which is mounted in the center fuselage and near the BRS. To mitigate that risk, I will
> > > >>>> order the optional motor controller fire suppression system.
> > > >>>>
> > > >>>> A fire suppression option is also available for the wing mounted batteries, and I am
> > > >>>> considering ordering that system, too.
> > > >>>> On 4/4/2022 11:02 AM, Dan Marotta wrote:
> > > >>>>> ...And I have plans in place for the unfortunate eventually.
> > > >> ...
> > > >>>> --
> > > >>>> Eric Greenwell - USA
> > > >>>> - "A Guide to Self-launching Sailplane Operation"
> > > >>>> https://sites.google.com/site/motorgliders/publications
> > > >>>
> > > >>> Unfortunately, lithium battery fires can't be suppressed - they generate their own oxygen unlike gasoline fires (it's built into the chemistry). I have been repeating this warning most times that I post about lithium battery fires. A friend of mine cancelled his order for a Jeta for this very reason.
> > > >>>
> > > >>> Tom
> > > >> My main concern is electronic motor controller, for which there are several types of fire
> > > >> suppression systems. I don't have the details of that system or the battery fire
> > > >> suppression system, so I can't describe either of them, nor do I what "fire" they will be
> > > >> trying to suppress in the wing where the batteries are mounted. It may be a structure
> > > >> fire, and not the battery fire. If the structure could be protected for, say, 10 minutes,
> > > >> that would give the pilot time to descend and land normally, or deploy the parachute at
> > > >> about 1000' AGL, from where he can be on the ground in less than a minute.
> > > >>
> > > >> Before I order either system, I'll have the complete details to guide my decision.
> > > >> --
> > > >> Eric Greenwell - USA
> > > >> - "A Guide to Self-launching Sailplane Operation"
> > > >> https://sites.google.com/site/motorgliders/publications
> > > >
> > > > I would not be concerned about the motor controller - it doesn't have any fuel source that can burn, but generates heat only as long as an energy source (electrical current) is supplied. Interrupt the current and the "fire" stops. That is what fuses are for.
> > > >
> > > > Ten minutes wasn't available to the Taurus Electro pilot - he was incapacitated in seconds.
> > > >
> > > > Tom
> > > That Taurus is a very different design than the Jetta, and was not as safe (in my
> > > estimation), for these reasons (and others):
> > > - The batteries were in the fuselage, instead of the wing like the Jeta
> > > - the batteries were foil pouches; the Jeta uses cells that are manufactured with a metal
> > > container
> > > - the Taurus batteries were routinely removed and potentially subjected to dropping
> > >
> > > Even so, I believe the changes made since that fire substantially improved the safety of
> > > the Taurus, and I'd willing fly it.
> > > --
> > > Eric Greenwell - USA
> > > - "A Guide to Self-launching Sailplane Operation"
> > > https://sites.google.com/site/motorgliders/publications
> > One shouldn't immediately assume that cylindrical cells are safer than pouch cells. Besides the Tesla fire database I previously cited, here is Tesla battery farm fire in Australia:
> > https://www.cnbc.com/2021/07/30/tesla-megapack-caught-fire-at-victorian-big-battery-site-in-australia.html
> > https://stopthesethings.com/2021/07/31/battery-bombs-more-giant-renewable-energy-batteries-explode-in-toxic-fireballs/
> > Tesla batteries, of course, use cylindrical cells, and are in a controlled, non-vibration environment. In other words, battery farms should be the LEAST LIKELY environment for a battery fire. Aircraft are subject to repeated positive and negative g-loading as well as significant vibration while flown in turbulent air.
> >
> > Placing the batteries in the wings may position them modestly further away from the pilot than the fuselage, but does it prevent fire fumes from reaching the pilot? In any event, a major fire in the wing(s) is a very serious situation, and would probably compromise the BRS.
> >
> > Tom

Not sure which dead horse you are beating. Tesla has been switching from NMC to LFP chemistries for their Megapacks and their shorter range cars. But the Tesla fire database doesn't indicate which chemistry was at fault, but it is very likely NMC.

Tom

On Friday, April 8, 2022 at 6:43:29 AM UTC-7, Eric Greenwell wrote:
> On 4/7/2022 9:49 PM, 2G wrote:
> > On Wednesday, April 6, 2022 at 8:38:18 PM UTC-7, Eric Greenwell wrote:
> ...
> >> I was speaking specifically about the Taurus situation. After that accident, there were
> >> major changes in design and manufacturing, and EASA regulations, that likely make pouch
> >> and cylindrical systems much closer in safety.
> >>
> >> A major fire anywhere on an aircraft is a very serious situation! Obviously, the
> >> manufacturers know this, and design the battery pack and it's installation reduce the
> >> risk. For example, the wing roots are sealed to prevent fumes from entering the fuselage,
> >> and venting is used to discharge the fumes from the wing. This shows a fume vent on the
> >> Antares:
> >>
> >> https://nordicgliding-com.translate.goog/opdateret-lange-antares-faar-tesla-batterier/?_x_tr_sl=da&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui
> >>
> >> Scroll down about half way to "Great demands on security".
> >>
> >> Vibration and G loads while operating a glider isn't a problem for the cylindrical cells,
> >> as they are very sturdy. Look up the specs for a typical 16850 cell, such as the
> >> Sony/Murata VCT6 cells used in the Jeta.
> >
> > This is a statement devoid of evidence. I, on the other hand, presented PLENTY of evidence to the contrary.
> >
> > Tom
> 18650 cells are used by the military, NASA rockets them into space, and EASA and others
> allow their use in aircraft. So please, take the time to look up the physical specs
> (vibration, etc) on the VCT6 cells, or pretty much any 18650 cell of the same chemistry.
> Those are the ones used in gliders. Once you have those specs, you can compare the specs
> to the loads those batteries experience in glider use. That's the evidence you need to
> show us if you want to persuade anyone a glider is a "rough ride"!
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications

Eric,

I would if I could - the manufacturers don't provide any specs on vibration or shock that I have seen, indicating that they don't test for this. NASA doesn't use large quantities of batteries, so they won't provide any useful information. EASA also certified the problematic Taurus Electro. This falls into the category of absence of proof is not proof of absence. The ONLY proof I recognize are actual fires.

Tom

On 4/9/2022 11:49 PM, 2G wrote:
> On Friday, April 8, 2022 at 6:43:29 AM UTC-7, Eric Greenwell wrote:
>> On 4/7/2022 9:49 PM, 2G wrote:
>>> On Wednesday, April 6, 2022 at 8:38:18 PM UTC-7, Eric Greenwell wrote:
>> ...
>>>> I was speaking specifically about the Taurus situation. After that accident, there were
>>>> major changes in design and manufacturing, and EASA regulations, that likely make pouch
>>>> and cylindrical systems much closer in safety.
>>>>
>>>> A major fire anywhere on an aircraft is a very serious situation! Obviously, the
>>>> manufacturers know this, and design the battery pack and it's installation reduce the
>>>> risk. For example, the wing roots are sealed to prevent fumes from entering the fuselage,
>>>> and venting is used to discharge the fumes from the wing. This shows a fume vent on the
>>>> Antares:
>>>>
>>>> https://nordicgliding-com.translate.goog/opdateret-lange-antares-faar-tesla-batterier/?_x_tr_sl=da&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui
>>>>
>>>> Scroll down about half way to "Great demands on security".
>>>>
>>>> Vibration and G loads while operating a glider isn't a problem for the cylindrical cells,
>>>> as they are very sturdy. Look up the specs for a typical 16850 cell, such as the
>>>> Sony/Murata VCT6 cells used in the Jeta.
>>>
>>> This is a statement devoid of evidence. I, on the other hand, presented PLENTY of evidence to the contrary.
>>>
>>> Tom
>> 18650 cells are used by the military, NASA rockets them into space, and EASA and others
>> allow their use in aircraft. So please, take the time to look up the physical specs
>> (vibration, etc) on the VCT6 cells, or pretty much any 18650 cell of the same chemistry.
>> Those are the ones used in gliders. Once you have those specs, you can compare the specs
>> to the loads those batteries experience in glider use. That's the evidence you need to
>> show us if you want to persuade anyone a glider is a "rough ride"!
>> --
>> Eric Greenwell - USA
>> - "A Guide to Self-launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications
>
> Eric,
>
> I would if I could - the manufacturers don't provide any specs on vibration or shock that I have seen, indicating that they don't test for this. NASA doesn't use large quantities of batteries, so they won't provide any useful information. EASA also certified the problematic Taurus Electro. This falls into the category of absence of proof is not proof of absence. The ONLY proof I recognize are actual fires.
>
> Tom
The certification standards have changed substantially because of the Taurus fire, and as
I have pointed out before, it was a very different design than what Schleicher is
producing. You have offered no evidence, much less proof, that the "actual fires" resulted
from vibration or G loading. And, if NASA's experience doesn't provide useful information
because their battery packs are smaller than glider pack, then I will continue to claim
car fires or utility fires also do not provide useful information, since they use ten
times to thousands of times as many batteries.

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

They should design electric gliders with the ability to drop the batteries in an emergency (in Star Trek parlance … eject the warp core!)

On Sunday, April 10, 2022 at 9:28:18 AM UTC-4, Eric Greenwell wrote:
> On 4/9/2022 11:49 PM, 2G wrote:
> > On Friday, April 8, 2022 at 6:43:29 AM UTC-7, Eric Greenwell wrote:
> >> On 4/7/2022 9:49 PM, 2G wrote:
> >>> On Wednesday, April 6, 2022 at 8:38:18 PM UTC-7, Eric Greenwell wrote:
> >> ...
> >>>> I was speaking specifically about the Taurus situation. After that accident, there were
> >>>> major changes in design and manufacturing, and EASA regulations, that likely make pouch
> >>>> and cylindrical systems much closer in safety.
> >>>>
> >>>> A major fire anywhere on an aircraft is a very serious situation! Obviously, the
> >>>> manufacturers know this, and design the battery pack and it's installation reduce the
> >>>> risk. For example, the wing roots are sealed to prevent fumes from entering the fuselage,
> >>>> and venting is used to discharge the fumes from the wing. This shows a fume vent on the
> >>>> Antares:
> >>>>
> >>>> https://nordicgliding-com.translate.goog/opdateret-lange-antares-faar-tesla-batterier/?_x_tr_sl=da&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui
> >>>>
> >>>> Scroll down about half way to "Great demands on security".
> >>>>
> >>>> Vibration and G loads while operating a glider isn't a problem for the cylindrical cells,
> >>>> as they are very sturdy. Look up the specs for a typical 16850 cell, such as the
> >>>> Sony/Murata VCT6 cells used in the Jeta.
> >>>
> >>> This is a statement devoid of evidence. I, on the other hand, presented PLENTY of evidence to the contrary.
> >>>
> >>> Tom
> >> 18650 cells are used by the military, NASA rockets them into space, and EASA and others
> >> allow their use in aircraft. So please, take the time to look up the physical specs
> >> (vibration, etc) on the VCT6 cells, or pretty much any 18650 cell of the same chemistry.
> >> Those are the ones used in gliders. Once you have those specs, you can compare the specs
> >> to the loads those batteries experience in glider use. That's the evidence you need to
> >> show us if you want to persuade anyone a glider is a "rough ride"!
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications
> >
> > Eric,
> >
> > I would if I could - the manufacturers don't provide any specs on vibration or shock that I have seen, indicating that they don't test for this. NASA doesn't use large quantities of batteries, so they won't provide any useful information. EASA also certified the problematic Taurus Electro. This falls into the category of absence of proof is not proof of absence. The ONLY proof I recognize are actual fires.
> >
> > Tom
> The certification standards have changed substantially because of the Taurus fire, and as
> I have pointed out before, it was a very different design than what Schleicher is
> producing. You have offered no evidence, much less proof, that the "actual fires" resulted
> from vibration or G loading. And, if NASA's experience doesn't provide useful information
> because their battery packs are smaller than glider pack, then I will continue to claim
> car fires or utility fires also do not provide useful information, since they use ten
> times to thousands of times as many batteries.
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications

On Sun, 10 Apr 2022 07:03:01 -0700 (PDT), stephen.s...@gmail.com wrote:

> They should design electric gliders with the ability to drop the
> batteries in an emergency (in Star Trek parlance … eject the warp core!)
>
THAT will work well!

"Be the first person on your block to claim for falling battery damage
wrecking your roof, setting fire to your house and killing your cat."

Or are you suggesting that each battery pack must be fitted with with a
fireproof, self-deploying emergency parachute?

So you are opposed to ballistic parachute systems as well … in case the aircraft falls on a cat?

On Sunday, April 10, 2022 at 10:44:12 AM UTC-4, Martin Gregorie wrote:
> On Sun, 10 Apr 2022 07:03:01 -0700 (PDT), stephen.s...@gmail.com wrote:
>
> > They should design electric gliders with the ability to drop the
> > batteries in an emergency (in Star Trek parlance … eject the warp core!)
> >
> THAT will work well!
>
> "Be the first person on your block to claim for falling battery damage
> wrecking your roof, setting fire to your house and killing your cat."
>
> Or are you suggesting that each battery pack must be fitted with with a
> fireproof, self-deploying emergency parachute?

On Sunday, 10 April 2022 at 08:49:44 UTC+2, 2G wrote:
> EASA also certified the problematic Taurus Electro. This falls into the category of absence of proof is not proof of absence. The ONLY proof I recognize are actual fires.

No, the Taurus (electro or otherwise) is not EASA certified. The ones flying in Europe are registered as ultra light (which don't follow EASA rules) or experimental.