Which 18m FES sailplane to buy?

On 11/27/18 9:01 PM, 2G wrote:
On Tuesday, November 27, 2018 at 12:22:06 PM UTC-8, wrote:
On Tuesday, November 27, 2018 at 2:26:46 PM UTC-5, Matt Herron (Sr) wrote:
Hi John:
I'm 5'7", so I can't help you on fit. But I found both the LAK17 and the Mini completely comfortable, and I think there was extra room beyond my personal dimensions. The 17 and the Mini essentially have the same fuselage, so if you've ever sat in a 17, you would probably find the Mini about the same fit.

As for batteries, I assume one could get support through US/Canadian distributor, but my guess is that any serious repairs would have to come from LZ in Slovenia.

As you probably know, LZ recalled all FES batteries for inspection and upgrade following the two battery fires. Here's what I wrote about that issue for Soaring:

In accordance with a Modification Bulletin
issued by the European Aviation Safety Agency
(EASA), the LAK factory has reinforced the
battery pack housing with flame retardant
fiberglass, installed an independent fire
warning system, and added a safety valve smoke
vent to the battery compartment cover.

The FES system has been with us for about
eight years now. During this time some 180
gliders have been fitted with the engine,
either as self-launch or sustainer. /There
have been no reported engine failures in
flight./ However, there have been two fires
involving the lithium polymer battery packs at
the heart of the FES system. One happened
during a landing in the UK and was
extinguished after the pilot exited the glider
safely. The pilot reported that one of the
battery packs had previously been dropped,
which could have damaged one or more of the
lithium cells. The other fire occurred in a
trailer where the batteries had been stored
with the units still connected, a big “no no“
according to FES maintenance manuals. While
the exact cause of the fires has not been
determined, any fire involving lithium
batteries can be extremely serious – these
units pack a lot of energy and must be handled
with respect.


In response to the fires, LZ Design, the
Slovenian manufacturer of the FES system, has
recalled all the battery packs for disassembly
and inspection. LZ is checking for the
suspected presence of small metal shards, a
possible by-product of machine work on the
battery case cover. Since the individual
lithium cells are housed in plastic bags
rather than hard cases, if a shard were
present it would be possible for it to migrate
during battery usage and penetrate a lithium
cell, potentially causing a short and a
resulting fire. After each inspection is
complete, LZ re-installs all the lithium cells
in a solid matrix of silicon gel, which should
correct the problem.

Regards,

Matt Herron

3 fires. One in the US
UH

I went to the FES presentation in Reno this year. I was unimpressed in the resolution of the fires that have occurred (I am an electrical engineer), especially in not acknowledging the third fire. My advice is to wait until the root cause of these fires has been conclusively identified. Having a parachute (as one friend of mine opined) is not an adequate backup plan.

Tom


The third fire was disclosed in one of the papers I read, it was about
40 pages on the testing and corrective actions that were being taken.

It did strike me as random shotgunning of fixes, replacing the carbon
fiber battery cases with fiberglass would seem to be minimally effective
for a lithium fire. Improving the terminal insulation, when terminal
insulation had no apparent involvement in the fires, may not do
anything. Hard to argue with an improved fire detection system, but
does nothing to prevent the fires.

-Dave

On 11/27/18 9:01 PM, 2G wrote:
On Tuesday, November 27, 2018 at 12:22:06 PM UTC-8, wrote:
On Tuesday, November 27, 2018 at 2:26:46 PM UTC-5, Matt Herron (Sr) wrote:
Hi John:
I'm 5'7", so I can't help you on fit. But I found both the LAK17 and the Mini completely comfortable, and I think there was extra room beyond my personal dimensions. The 17 and the Mini essentially have the same fuselage, so if you've ever sat in a 17, you would probably find the Mini about the same fit.

As for batteries, I assume one could get support through US/Canadian distributor, but my guess is that any serious repairs would have to come from LZ in Slovenia.

As you probably know, LZ recalled all FES batteries for inspection and upgrade following the two battery fires. Here's what I wrote about that issue for Soaring:

In accordance with a Modification Bulletin
issued by the European Aviation Safety Agency
(EASA), the LAK factory has reinforced the
battery pack housing with flame retardant
fiberglass, installed an independent fire
warning system, and added a safety valve smoke
vent to the battery compartment cover.

The FES system has been with us for about
eight years now. During this time some 180
gliders have been fitted with the engine,
either as self-launch or sustainer. /There
have been no reported engine failures in
flight./ However, there have been two fires
involving the lithium polymer battery packs at
the heart of the FES system. One happened
during a landing in the UK and was
extinguished after the pilot exited the glider
safely. The pilot reported that one of the
battery packs had previously been dropped,
which could have damaged one or more of the
lithium cells. The other fire occurred in a
trailer where the batteries had been stored
with the units still connected, a big “no no“
according to FES maintenance manuals. While
the exact cause of the fires has not been
determined, any fire involving lithium
batteries can be extremely serious – these
units pack a lot of energy and must be handled
with respect.


In response to the fires, LZ Design, the
Slovenian manufacturer of the FES system, has
recalled all the battery packs for disassembly
and inspection. LZ is checking for the
suspected presence of small metal shards, a
possible by-product of machine work on the
battery case cover. Since the individual
lithium cells are housed in plastic bags
rather than hard cases, if a shard were
present it would be possible for it to migrate
during battery usage and penetrate a lithium
cell, potentially causing a short and a
resulting fire. After each inspection is
complete, LZ re-installs all the lithium cells
in a solid matrix of silicon gel, which should
correct the problem.

Regards,

Matt Herron

3 fires. One in the US
UH

I went to the FES presentation in Reno this year. I was unimpressed in the resolution of the fires that have occurred (I am an electrical engineer), especially in not acknowledging the third fire. My advice is to wait until the root cause of these fires has been conclusively identified. Having a parachute (as one friend of mine opined) is not an adequate backup plan.

Tom


Page number 38, brief mention

https://assets.publishing.service.go...GSGS_09-18.pdf

Dne sreda, 28. november 2018 05.01.09 UTC+1 je oseba 2G napisala:
On Tuesday, November 27, 2018 at 12:22:06 PM UTC-8, wrote:
On Tuesday, November 27, 2018 at 2:26:46 PM UTC-5, Matt Herron (Sr) wrote:
Hi John:
I'm 5'7", so I can't help you on fit. But I found both the LAK17 and the Mini completely comfortable, and I think there was extra room beyond my personal dimensions. The 17 and the Mini essentially have the same fuselage, so if you've ever sat in a 17, you would probably find the Mini about the same fit.

As for batteries, I assume one could get support through US/Canadian distributor, but my guess is that any serious repairs would have to come from LZ in Slovenia.

As you probably know, LZ recalled all FES batteries for inspection and upgrade following the two battery fires. Here's what I wrote about that issue for Soaring:

In accordance with a Modification Bulletin
issued by the European Aviation Safety Agency
(EASA), the LAK factory has reinforced the
battery pack housing with flame retardant
fiberglass, installed an independent fire
warning system, and added a safety valve smoke
vent to the battery compartment cover.

The FES system has been with us for about
eight years now. During this time some 180
gliders have been fitted with the engine,
either as self-launch or sustainer. /There
have been no reported engine failures in
flight./ However, there have been two fires
involving the lithium polymer battery packs at
the heart of the FES system. One happened
during a landing in the UK and was
extinguished after the pilot exited the glider
safely. The pilot reported that one of the
battery packs had previously been dropped,
which could have damaged one or more of the
lithium cells. The other fire occurred in a
trailer where the batteries had been stored
with the units still connected, a big “no no“
according to FES maintenance manuals. While
the exact cause of the fires has not been
determined, any fire involving lithium
batteries can be extremely serious – these
units pack a lot of energy and must be handled
with respect.


In response to the fires, LZ Design, the
Slovenian manufacturer of the FES system, has
recalled all the battery packs for disassembly
and inspection. LZ is checking for the
suspected presence of small metal shards, a
possible by-product of machine work on the
battery case cover. Since the individual
lithium cells are housed in plastic bags
rather than hard cases, if a shard were
present it would be possible for it to migrate
during battery usage and penetrate a lithium
cell, potentially causing a short and a
resulting fire. After each inspection is
complete, LZ re-installs all the lithium cells
in a solid matrix of silicon gel, which should
correct the problem.

Regards,

Matt Herron

3 fires. One in the US
UH

I went to the FES presentation in Reno this year. I was unimpressed in the resolution of the fires that have occurred (I am an electrical engineer), especially in not acknowledging the third fire. My advice is to wait until the root cause of these fires has been conclusively identified. Having a parachute (as one friend of mine opined) is not an adequate backup plan.

Tom

Dear Tom,

I think you did not listening carefully, as it was mentioned. The problem with 3rd fire was that owner of the glider was informed and asked by the factory not to use his batteries. So this this 3rd fire could be easily avoided, but he could not resist to use his batteries. This happened when we already had a solution and it was part of the same problem, which could be easily avoided.

Regards,
Luka

Hi Luka,
thanks for joining this discussion.
While refurbishing the batterypacks you have seen all these packs after years of use. Do you think, that these swarf were causing the fires?
Or what do you think was the root cause of the fires?
greets
Lukas

On Wednesday, November 28, 2018 at 2:45:01 AM UTC-8, Luka Žnidarši� wrote:
Dne sreda, 28. november 2018 05.01.09 UTC+1 je oseba 2G napisala:
On Tuesday, November 27, 2018 at 12:22:06 PM UTC-8, wrote:
On Tuesday, November 27, 2018 at 2:26:46 PM UTC-5, Matt Herron (Sr) wrote:
Hi John:
I'm 5'7", so I can't help you on fit. But I found both the LAK17 and the Mini completely comfortable, and I think there was extra room beyond my personal dimensions. The 17 and the Mini essentially have the same fuselage, so if you've ever sat in a 17, you would probably find the Mini about the same fit.

As for batteries, I assume one could get support through US/Canadian distributor, but my guess is that any serious repairs would have to come from LZ in Slovenia.

As you probably know, LZ recalled all FES batteries for inspection and upgrade following the two battery fires. Here's what I wrote about that issue for Soaring:

In accordance with a Modification Bulletin
issued by the European Aviation Safety Agency
(EASA), the LAK factory has reinforced the
battery pack housing with flame retardant
fiberglass, installed an independent fire
warning system, and added a safety valve smoke
vent to the battery compartment cover.

The FES system has been with us for about
eight years now. During this time some 180
gliders have been fitted with the engine,
either as self-launch or sustainer. /There
have been no reported engine failures in
flight./ However, there have been two fires
involving the lithium polymer battery packs at
the heart of the FES system. One happened
during a landing in the UK and was
extinguished after the pilot exited the glider
safely. The pilot reported that one of the
battery packs had previously been dropped,
which could have damaged one or more of the
lithium cells. The other fire occurred in a
trailer where the batteries had been stored
with the units still connected, a big “no no“
according to FES maintenance manuals. While
the exact cause of the fires has not been
determined, any fire involving lithium
batteries can be extremely serious – these
units pack a lot of energy and must be handled
with respect.


In response to the fires, LZ Design, the
Slovenian manufacturer of the FES system, has
recalled all the battery packs for disassembly
and inspection. LZ is checking for the
suspected presence of small metal shards, a
possible by-product of machine work on the
battery case cover. Since the individual
lithium cells are housed in plastic bags
rather than hard cases, if a shard were
present it would be possible for it to migrate
during battery usage and penetrate a lithium
cell, potentially causing a short and a
resulting fire. After each inspection is
complete, LZ re-installs all the lithium cells
in a solid matrix of silicon gel, which should
correct the problem.

Regards,

Matt Herron

3 fires. One in the US
UH

I went to the FES presentation in Reno this year. I was unimpressed in the resolution of the fires that have occurred (I am an electrical engineer), especially in not acknowledging the third fire. My advice is to wait until the root cause of these fires has been conclusively identified. Having a parachute (as one friend of mine opined) is not an adequate backup plan.

Tom

Dear Tom,

I think you did not listening carefully, as it was mentioned. The problem with 3rd fire was that owner of the glider was informed and asked by the factory not to use his batteries. So this this 3rd fire could be easily avoided, but he could not resist to use his batteries. This happened when we already had a solution and it was part of the same problem, which could be easily avoided.

Regards,
Luka

Perhaps I didn't listen carefully enough, but I was listening carefully - it was not a part of your presentation, but a question from the audience. Whether the 3rd fire could have been avoided is not the issue here. It is probably better, from a safety analysis standpoint, that it DID occur.

I have read the AAIB report, which was very thorough. The most disturbing part was that there was no root cause found for these fires. Your manufacturing process was careless, which has been corrected, but this wasn't determined to be the cause. The recommendations deal only with mitigating the effects of a fire once it starts. I am concerned that fires will continue to happen. I can only conclude that there are random defects occurring during the manufacture of the cells, and there has been no change made in this area.

Tom

John,

I took a chance to try on Jamie Shore's Mini LAK here at SCOH and I did fit - barely. I am 6'2" and I think with some fiddling of the seat cushion type I would fit very comfortably. Did not get to fly it so cannot comment on how comfortable I would be after 3 to 4 hours in it - guess I'll have to fly before I buy.

Tony Smolder
TS1

While I sypathize with Dan Marotta's point of view (and emphatically with John Hebert's) , I think a small dose of reality salts may be in order here.

1) Defective Lythium batteries are a SERIOUS fire hazard! And Lythium fires can be extremely intense. Would you want to schedule your trans Atlantic filght on an aircraft that due to “changing regulations� was carrying those defective batteries in its cargo hold? How would you feel if you were the captain of a container ship? Wonderful though those batteries are, they are still probably the Achellies Heel of the FES system.

2) The FES system (which I firmly believe to be the future of motor gliding) is still in its infancy. How large is the current FES customer base in North (South?) America? As that base expands, it may be reasoable to expect dealors to stock a limited supply of loaner batteries, Right now, probably not.

3) We all owe a debt of gratitude to the folks at LZ Designs for creating a remarkable advancement in glider power. Since it's inception the FES system has already gone through three design enhancements. And since Luca and his folks seem intent on further design improvements (rather than just sitting back and enjoying their profits), I think we can expect much innovation in a few short years. What will FES be like in ten years?

Very good perspective, Matt.Â* Points that I did not consider.

On 11/30/2018 12:42 PM, Matt Herron (Sr) wrote:
While I sypathize with Dan Marotta's point of view (and emphatically with John Hebert's) , I think a small dose of reality salts may be in order here.

1) Defective Lythium batteries are a SERIOUS fire hazard! And Lythium fires can be extremely intense. Would you want to schedule your trans Atlantic filght on an aircraft that due to “changing regulations� was carrying those defective batteries in its cargo hold? How would you feel if you were the captain of a container ship? Wonderful though those batteries are, they are still probably the Achellies Heel of the FES system.

2) The FES system (which I firmly believe to be the future of motor gliding) is still in its infancy. How large is the current FES customer base in North (South?) America? As that base expands, it may be reasoable to expect dealors to stock a limited supply of loaner batteries, Right now, probably not.

3) We all owe a debt of gratitude to the folks at LZ Designs for creating a remarkable advancement in glider power. Since it's inception the FES system has already gone through three design enhancements. And since Luca and his folks seem intent on further design improvements (rather than just sitting back and enjoying their profits), I think we can expect much innovation in a few short years. What will FES be like in ten years?



--
Dan, 5J

Hello again everyone,

You all made my point, precisely. So just how many units of various models of FES equipped sailplanes do we need here in North America to reach critical mass, or, where a 'fleet' of aircraft is large enough to make it feasible to have a reserve of batteries on hand somewhere, anywhere? How difficult is it, for example, to have a large and wonderfully successful sport aviation components company the likes of 'Spruce and Specialty', or even our beloved 'Wings and Wheels', to stock a 'reasonable' number of serviceable batteries, either new or reconditioned? Appropriately enough, some of these same company already carry a line of batteries, with all manners of exotic chemicals, from lead acid, to Nicad, to gel, to lithium, to.....whatever the industry needs, and they possess the shipping expertise to deliver these dangerous goods 'overland' pretty much anywhere within a reasonable delay.

Now, please don’t think I am unsympathetic to the enormous efforts made by Luka in resolving these HUGE technological challenges. Quite au contraire mes amis, but before I pluck out anywhere between 120 000 and 200 000 American dineros on new glass, equipped with this marvellous new technology, I and many others need to see improvements in this area. And I wholeheartedly agree with Matt, this IS the future, however a dose of realism is required here. Please chime in here Lukas, yours is the voice that counts the most.

And to the other view expressed about relaxing transportation and handling regulations; as an airline pilot for our national carrier, that is the last thing I want to see happen. On any given flight, we are already carrying anywhere between 50 and 400 kg of lithium batteries IN THE CABIN as it is, depending on one's estimate. Our low cost division alone loads them by the trolley full as part of our on-board entertainment system, which on the narrow body jet is 20 kg or more just for this purpose, and from there it just escalates. Why just on the flight deck, with our jepessen airways and company manuals which are now fully iPad integrated, there is another 5 kg, if you count our personal smartphones and tablets.....anyway, you get my drift.. If anything, expect the regulations to get more complex and convoluted, not the other way around.

Thank you, it is a real pleasure.

John Hebert

I thought the propellor hub problems were with the DG1000 &
Duo Turbo?
I wasn't aware the Antares 18T had this problem as their hub
design is different?
Dave Walsh