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-   -   Electric plane prototype caught fire (https://www.pprune.org/rumours-news/629133-electric-plane-prototype-caught-fire.html)

gearlever 24th Jan 2020 15:39

Electric plane prototype caught fire
 
Eviation Alice prototype damaged by electric fire

Looks like fire started from an external battery unit.
So no worries....

OldnGrounded 24th Jan 2020 17:27


Originally Posted by gearlever (Post 10670485)
Eviation Alice prototype damaged by electric fire

Looks like fire started from an external battery unit.
So no worries....

Yup. As long as the batteries are kept on the ground, everything will be OK.

ATC Watcher 24th Jan 2020 18:54

Bad times for electric propulsion , a large drone overflying a large crowd in a festival fell in the public in south of France , injuring 2 due to a battery failure,the medium size UK police surveillance drones falling down due to rain in electrical systems and now this ... Lots of work to be done before it is will carry paying pax I would say .

capngrog 24th Jan 2020 22:15

“Eviation Aircraft experienced a fire incident during system testing of one of its aircraft at the Prescott Regional airport,” the company says in a statement. The incident “is believed to have been caused by a ground-based battery system which was being utilised during rigorous testing of its all-electric airplane”.

" ... ground-based battery system ..." A charging system perhaps? As far as my limited knowledge of the technology goes, most fires involving high energy density batteries, such as Lithium-ion, result from too rapid charging or discharging and result in fires involving the batteries themselves and not the charging systems or discharging loads. Since this incident involves a very promising yet evolving technology, I would think that the NTSB would be interested. The investigation and report should be very interesting.

At least nobody was injured.

Cheers,
Grog

tucumseh 25th Jan 2020 08:51

MoD Lithium-Ion battery trials, 1991

https://i214.photobucket.com/albums/...psjs5hkjpr.jpg

MorayC 25th Jan 2020 16:05


Originally Posted by capngrog (Post 10670754)
“Eviation Aircraft experienced a fire incident during system testing of one of its aircraft at the Prescott Regional airport,” the company says in a statement. The incident “is believed to have been caused by a ground-based battery system which was being utilised during rigorous testing of its all-electric airplane”.

" ... ground-based battery system ..." A charging system perhaps? As far as my limited knowledge of the technology goes, most fires involving high energy density batteries, such as Lithium-ion, result from too rapid charging or discharging and result in fires involving the batteries themselves and not the charging systems or discharging loads. Since this incident involves a very promising yet evolving technology, I would think that the NTSB would be interested. The investigation and report should be very interesting.

I wonder if they've been testing some kind of battery to battery charging to minimise charging times, and not be restricted by how much mains power is available?

ThreeThreeMike 26th Jan 2020 03:57


Originally Posted by MorayC (Post 10671349)
I wonder if they've been testing some kind of battery to battery charging to minimise charging times, and not be restricted by how much mains power is available?

They were using an external battery for testing because the onboard battery had insufficient capacity for the test being performed. The fire started for the reason many electrical fires start, inadequate conductor sizing for the circuit current, and lack of an overcurrent protective device, AKA a circuit breaker.

Andrewgr2 26th Jan 2020 06:15

That’s shocking if true. And incompetent in the extreme.

turbidus 26th Jan 2020 12:27

Wow, I fly Cape Air quite often.

andrasz 27th Jan 2020 07:43

Am I the only one wondering about the wisdom of merrily dousing an electric fire with water and foam ... ?
(video in OP)

Twitter 27th Jan 2020 08:41


Originally Posted by andrasz (Post 10672711)
Am I the only one wondering about the wisdom of merrily dousing an electric fire with water and foam ... ?
(video in OP)

Depends what you are trying to save - on the ground.

On the other hand don’t spill your coffee on the pedestal - in flight.

capngrog 27th Jan 2020 12:31


Originally Posted by andrasz (Post 10672711)
Am I the only one wondering about the wisdom of merrily dousing an electric fire with water and foam ... ?
(video in OP)

You have touched on what will be a BIG problem for aircraft accident Emergency Responders. Electric automobiles are already a BIG problem for Emergency Responders, with the Tesla system using around 375 volts and the Porsche Taycan about 800 volts. Dousing a flaming wreck with water and foam is usually the only option for most Fire Fighting organizations and is usually effective on hydrocarbon fuel fires; however, the materials used in the current crop of high energy density (HED) batteries (such as Lithium) are pyrophoric and ignite when exposed to air. Lithium will also react with water, but at a much slower rate than, for example, Sodium metal. The technology of HED batteries is rapidly evolving, and my limited understanding of their chemistry may be outdated, but the electrical hazard is pretty much a given. Isolation switches for an HED battery will confine electrical hazards to the battery pack itself if electrical circuits are undamaged; however, it can be expected that most systems will be damaged or otherwise compromised in an aircraft accident. Physical damage to the batteries themselves can also cause fire. I'm not sure that the hazards associated with electric-powered flight are fully understood at this point in time. I can say for certain, however, that those hazards are not fully understood by me.

Hopefully, there will be other posters on this thread who have a more complete understanding of the hazards associated with electric-powered flight.

Cheers,
Grog

Ex Cargo Clown 27th Jan 2020 12:48


Originally Posted by capngrog (Post 10672898)
You have touched on what will be a BIG problem for aircraft accident Emergency Responders. Electric automobiles are already a BIG problem for Emergency Responders, with the Tesla system using around 375 volts and the Porsche Taycan about 800 volts. Dousing a flaming wreck with water and foam is usually the only option for most Fire Fighting organizations and is usually effective on hydrocarbon fuel fires; however, the materials used in the current crop of high energy density (HED) batteries (such as Lithium) are pyrophoric and ignite when exposed to air. Lithium will also react with water, but at a much slower rate than, for example, Sodium metal. The technology of HED batteries is rapidly evolving, and my limited understanding of their chemistry may be outdated, but the electrical hazard is pretty much a given. Isolation switches for an HED battery will confine electrical hazards to the battery pack itself if electrical circuits are undamaged; however, it can be expected that most systems will be damaged or otherwise compromised in an aircraft accident. Physical damage to the batteries themselves can also cause fire. I'm not sure that the hazards associated with electric-powered flight are fully understood at this point in time. I can say for certain, however, that those hazards are not fully understood by me.

Hopefully, there will be other posters on this thread who have a more complete understanding of the hazards associated with electric-powered flight.

Cheers,
Grog

Pretty sure they use a lithium polymer which isn't pyrophoric and not elemental lithium. If you go down the group 1 metals, Li is the least reactive and doesn't really burn in water either. It needs a lot of energy to combust, hence water being a good way of putting it out as it's self-fueling otherwise.

(This post is brought to you by an ex-chemistry student who managed to blow a phone battery up in a pumpkin and completely destroy it. I wouldn't fly in a Li-ion aircraft).

MCR01 27th Jan 2020 18:37

Well it's evolving technology so problems will continue to appear.
I do fly a Li-Ion powered self launch glider; I used to fly a gasoline powered self launch. Having 22 litres of petrol inches from your right shoulder in a millimetre thin GRP tank does not feel comfortable either!
It's a choice....

unmanned_droid 27th Jan 2020 19:44


Originally Posted by capngrog (Post 10672898)
You have touched on what will be a BIG problem for aircraft accident Emergency Responders. Electric automobiles are already a BIG problem for Emergency Responders, with the Tesla system using around 375 volts and the Porsche Taycan about 800 volts. Dousing a flaming wreck with water and foam is usually the only option for most Fire Fighting organizations and is usually effective on hydrocarbon fuel fires; however, the materials used in the current crop of high energy density (HED) batteries (such as Lithium) are pyrophoric and ignite when exposed to air. Lithium will also react with water, but at a much slower rate than, for example, Sodium metal. The technology of HED batteries is rapidly evolving, and my limited understanding of their chemistry may be outdated, but the electrical hazard is pretty much a given. Isolation switches for an HED battery will confine electrical hazards to the battery pack itself if electrical circuits are undamaged; however, it can be expected that most systems will be damaged or otherwise compromised in an aircraft accident. Physical damage to the batteries themselves can also cause fire. I'm not sure that the hazards associated with electric-powered flight are fully understood at this point in time. I can say for certain, however, that those hazards are not fully understood by me.

Hopefully, there will be other posters on this thread who have a more complete understanding of the hazards associated with electric-powered flight.

Cheers,
Grog

The Rimac that Richard Hammond crashed was catching fire due to battery cell shorts for 5 days after the crash.

I read a post from a fireman that said Tesla had held a training event to show the guys how to isolate and disconnect the batteries in a crash scenario, however this doesn't help with damaged cells. He confirmed the requirement to attend the crash for a long period of time to make sure any other shorts don't cause other fires.

He then went on to say that if you wanna talk about scary, consider hydrogen powered vehicles.

Atlas Shrugged 28th Jan 2020 01:18


Hopefully, there will be other posters on this thread who have a more complete understanding of the hazards associated with electric-powered flight.
I think we are a very, very, very long way from being anywhere near that position!

Winemaker 28th Jan 2020 02:23


Originally Posted by MCR01 (Post 10673169)
Well it's evolving technology so problems will continue to appear.
I do fly a Li-Ion powered self launch glider; I used to fly a gasoline powered self launch. Having 22 litres of petrol inches from your right shoulder in a millimetre thin GRP tank does not feel comfortable either!
It's a choice....

I'm curious. 22 liters of petrol is about 16.5 kg providing about 45 MJ/kg, so about 740 MJ total energy. Assuming 25% efficiency of a piston engine, that's about 185 MJ of available energy. Lithium batteries (middle range) energy density is 0.6 MJ/kg. So, assuming 100% efficiency of the electric side, that means that to equal the energy of the petrol, one would need a battery pack weighting 185 kg. How could this possibly work? Have I made a maths error?

capngrog 28th Jan 2020 04:18

The first aircraft crash I responded to was a Lockheed Jetstar that aborted its takeoff from 09L at MIA. The first officer was able to exit the cockpit window, but the captain perished in the post crash fire. The initial fire was extinguished, but fire continued to erupt for several hours after the crash until the battery was finally disconnected. Depending on the aircraft, the battery voltage is somewhere around 28 V DC, so I can imagine the problems that may be associated with the crash of an electrically-powered aircraft featuring voltages of around 400-800 V DC (or more).

Cheers,
Grog

unmanned_droid 28th Jan 2020 09:37


Originally Posted by Winemaker (Post 10673391)
I'm curious. 22 liters of petrol is about 16.5 kg providing about 45 MJ/kg, so about 740 MJ total energy. Assuming 25% efficiency of a piston engine, that's about 185 MJ of available energy. Lithium batteries (middle range) energy density is 0.6 MJ/kg. So, assuming 100% efficiency of the electric side, that means that to equal the energy of the petrol, one would need a battery pack weighting 185 kg. How could this possibly work? Have I made a maths error?

Nope, not really. That's the entire electric propulsion problem in a nutshell.


Mr Optimistic 28th Jan 2020 10:00

How do you protect the main drive from an overcurrent fault if you can't isolate the supply without loss of lift?


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