Boeing 787 Li-Ion Meltdown

[G7PSK]

They used to use NiFe batteries on aircraft as they had very good performance for the weight do they no longer use them. i know they are still made for industrial purposes.

[HLA-27b]

And the shit flinging competition has begun ladies and gents. 

Boeing says it may be a manufacturing defect in the batteries which effects only one batch.

Yuasa the Japanese manufacturer of the batteries says that the faults go beyond the batteries.

Thales, the French manufacturer of the electrical system hasn't flung any shit yet but it is expected of them to blame some third world country. Any minute now.


Source: The Japan Times Online

http://www.japantimes.co.jp/text/nb20130119n2.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+japantimes+%28The+Japan+Times%3A+All+Stories%29


edit:
BTW Did you know that Yuasa also has a battery contract for the ISS? Fire in space must be a fun thing indeed.    ?__?

http://www.japantimes.co.jp/text/nb20130119n4.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+japantimes+%28The+Japan+Times%3A+All+Stories%29

[SeanB]

ISS batteries are outside in a sealed compartment, so in case of oops they vent to vacuum. AFAIK they use a silver/silver oxide cell that has a life of millions of cycles, and is one of the few things that costs more to make than the shipping cost.

[G7PSK]

Is that the shipping cost to the ISS or to the launch site.

[SeanB]

Cost for launching the things on the Shuttle, they do not fit in a Proton.

[G7PSK]

So what happens when the present batteries die, how do they get a new one up now there is no shuttle, looks like the pen pushers did not think thing through again.

[notsob]

I would expect them to use the european automated vehicle or Spacex Falcon,which has completed 2 runs & is due for it's next flight around march time

[Bored@Work]

Fire in space must be a fun thing indeed.    ?__?

They have the Soyuz as an escape pod. And I seem to remember a tweed from a current ISS crew member that they always have taped possible re-entry schedules near the hatch to the Soyuz to make sure they have them at hand should they be in a hurry.

[Eliminateur]

those control boards have an AWFUL lot of electronics(no tonly one but TWO stacked boards in a can that big...) from what i see to just "protect" the cells(and at least a monitoring connection to each cell terminals and most likely several thermocouples around the cells) which to me begs the question: where where the alerts?? (in all the grounding cases the crew noticed SMOKE or FIRE, but no master warning prior...)
i mean if there was thermal runway(140°C) shouldn't all kinds of overtemp alarms be popping BEFORE the magic blue smoke & flame appears(and possibly charge/discharge cutout)?
Or when it's going in flames and cells open(thus again triggering some *kind* of alarm due to cell V going to zero), so what's the point of having so much overengineered supervisory electronics on the cells if the failure detection is "goes up in flames and smokes"?

granted i don't know how or what kind of interface those packs have with the avionics, but with that much board/components and knowing avionics and their overabundance of sensors there should be a ton of communication between avionics and those boards(with black box and stuff, there should be a lot of datalogging around)

edit: oh i almost forget, all articles i've seen about "speculate" that there might be the cells... or overcharge... again, you're going to tell me that those supervisory boards don't have any kind of datalogging embedded or transmitted outside?, i call BS or coverup.....

[ivan747]

3 why they don't pull the power from dynamos on the turbines.

They can't. They need these batteries to start the engines. And the batteries are the backup for power, should the engines fail in flight. It is my understanding they are the only source of power in such a case. So they are freaking important, and it is not only the fire as such what makes people nervous, but that they are badly needed in emergencies.

How do traditional aircraft get hydraulic pressure in case of complete engine failure?

And doesn't this has an Auxiliary Power Unit?

[Eliminateur]

3 why they don't pull the power from dynamos on the turbines.

They can't. They need these batteries to start the engines. And the batteries are the backup for power, should the engines fail in flight. It is my understanding they are the only source of power in such a case. So they are freaking important, and it is not only the fire as such what makes people nervous, but that they are badly needed in emergencies.

How do traditional aircraft get hydraulic pressure in case of complete engine failure?

And doesn't this has an Auxiliary Power Unit?

traditional aircraft get that from the APU or in case the APU fails, teh air-ram turbine(which is an hydraulic pump in every plane except the 787)

and yes, 787 has an APU like any airplane, but it's apu is just an electric generator instead of a air&hydraulic compressor/pump in normal airplanes.
But you need to start the APU, and that's what the batteries are for, for powering up the avionics until the APU starts

[G7PSK]

I understood that the APU drops down automatically in the event of a total power failure. Can Lithium cell burst into flames without first over heating, that would explain the lack of warning before smoke and flames appeared.

[Eliminateur]

I understood that the APU drops down automatically in the event of a total power failure. Can Lithium cell burst into flames without first over heating, that would explain the lack of warning before smoke and flames appeared.

don't confuse APU with the air-ram turbine, they're different things.
APU is not an emergency device per se, it's a "normal" device that sits on the tail of the plane usually(it's a small turbine in non-787 planes), you can notice that some planes have a exhaust in the tail cone that makes "no sense" as there are no engines there(excep on MCD planes), well that' the APU exhaust.
the air-ram IS an emergency device only which drops in case of total power failure(including APU, if the APU works no air-ram extends)

[ivan747]

Could the air-ram provide enough energy to start the APU?

[SeanB]

APU supplies power when on the ground and not plugged into the ground supply ( 28VDC @8kA peak and 115VAC 400Hz @50A) so that the systems can be started. The APU is what is used to start the engines, it is a little dicey to use the main battery to do that, as it is capable of it ( absolutely, it will deliver 8kA into a load with a terminal voltage of 22V) but then the charging will need limiting to prevent overcharge. These batteries have a slight negative temperature coefficient and thus droop in voltage as they get hot. Can be fun if you have a starter generator on the turbine which is quite capable of charging at over 2kA, and a simple carbon pile regulator that lowers current as the voltage increases. Newer aircraft just limit the charge current to something the battery will accept as overcharge without issue.

Batteries are often only monitored for voltage, and this is from a sensor set on the main DC battery bus. There are temperature sensors on many, but they are only going to tell you that the pack has exceeded 130C case temperature. ie it is either going to go or is actually cooking up.

I do not know of these Liion packs, but I would surmise they are only monitored by the maintenance processor and are not actually connected to the main warning system aside from the case sensor ( monitoring being done on DCbus1, DCbus2, DCbusaux and Dcbusemerg for voltage only) which may not be used ( half the planes I worked on either did not have the sensor in the battery, and a socket next to the battery to plug it so the warning system would not show disconnected; while the others did not have the wiring at all.) on all of the planes.

Ram air provides hydraulic power only to some flight systems, no electrics, that is done by the battery only, and will only be powering the standby  artificial horizon, the standby radio and a set of emergency lights in the cabin and cockpit. All other systems are gone aside from the minimum - attitude, altitude, compass heading and basic controls. landing gear is not supplied, you have to manually pump the emergency release and pump the doors open and then drop the gear by gravity and pump it till it locks. No brake power assist or ABS either, you climb on the pedals with both feet and push hard, and hope you stop before you run out of runway or that the tyres do not blow out from the heat.

Only one time that I was wishing I had a parachute when flying. But we landed and were able to walk away, and the plane was able to fly again as well.

[Eliminateur]

well since the 787 is so electronic and digital with everything fly-by-wire and that "boeing ethernet" and with it's reliance on electrical power for everything and looking at those huge supervisor boards i'm assuming it has a sea of sensors to monitor the batteries/buses(moreso taking into account that liion needs charge controllers and you can't simply plug them into the dc bus with a regulator and be done ).

anyone cares to find a 787 maintenance/operation manual?.

SeanB, daaaayum, what where you flying when power went poof like that?.
so if your batteries are out and you only have ram-air you're essentially flying pre-WW2?, no lights, horizons, radio, nothing?

[Skimask]

Generally, ya, if the batteries are out and your flying off the RAT, you've got minimal everything.
Maybe a few basic lights for the instrument panel, a self contained DC gyro for attitude and turn/bank, "steam gauges" (altitude, vertical velocity, airspeed), maybe a low wattage VHF radio for 121.5Mhz comm's, but that's about it.
Then again, that's all your really NEED to keep an airplane flying.
I always said the only thing I want when I'm flying is an oil pressure gauge.
I can see how high up I am, judge how fast I'm going, know how much fuel is likely left in the tanks (assuming I started with full tanks), can hear the engine rpms, and can put down on practically any half decent gravel road.  The only thing I can't see, hear, feel, smell is the oil pressure.  And by the time I "smell", "hear", "see" or "feel" something wrong with the oil pressure, it's too late and I'm gonna land whether I like it or not!

[jerry507]

The ram air turbine will definitely need to be more than a few lights and a gyro on the 787. It would need to supply electrical power for the hydraulic and pneumatic systems.

[SeanB]

Rliminateur, I was catching the bus to work..........

C47 Dekota, normally a 3 hour flight with one stop then mine. 7AM departure went ok, took off, climbed to 15000 and went north along the road to the first stop. Come there and when the pilots selected gear down had  from 3 blank to 3 red then 2 green one red. Tried a few times while doing circles around the runway seeing if the fault was air bubbles, but no go. Then looked out the front door ( me and the flight engineer both, leaning out under and looking, him much further out with my arm through his overall belt and the other around the seat stanchion, me calling out to the pilot the results) and we were pretty sure after looking it was an indication fault......

Best landing ever in a Dakota though, smooth and so gentle, though rather perturbing in having a 45 ton Pathfinder fire engine racing down the rough next to us with a foam cannon aimed and pumps running, along with a set of hoses laid out on top. Landed, parked and checked the switch, which was faulty, then gotback in and took off to go to my workplace. Landed and walked in just at closing time...... Was asked why so late told them the Flossie broke down and we had to push it to LT.

Still got a photo of that plane in an album ( film and paper) in a drawer.

[SoftwareSamurai]

Apparently it's not due to over-charging/over-voltage. So what else would cause a LiPo battery to burst into flames? Too much current perhaps?

[HLA-27b]

GS Yuasa lithium-ion losses look to grow

For GS Yuasa Corp., winning the deal to supply Boeing Co. offered the chance to make its first profit from selling lithium-ion batteries. The recent grounding of the 787 fleet on concerns about battery safety, however, means the company's losses on the technology will probably widen.

GS Yuasa's multiyear, multimillion dollar contract, announced in June 2005, to supply batteries to Thales SA for the electrical system of the 787 was an opportunity to offset losses from sales to carmakers. While GS Yuasa announced in 2009 that lithium-ion batteries for vehicles will become a core business, it hasn't been able to turn the technology into profit.

[...]

All four plants where GS Yuasa builds lithium-ion batteries are in Japan and the batteries supplied to the Dreamliners are made at a factory at its Kyoto headquarters. The electrical system, which the battery is embedded into, is manufactured by Thales, Europe's biggest defense-electronics maker.

Boeing chose lithium-ion batteries for the 787 because they hold more energy and can be quickly recharged.

Boeing got permission from regulators to use lithium-ion batteries in the jetliner in 2007, three years after U.S. passenger planes were barred from carrying nonrechargeable types as cargo because of their flammability.

[...]

full text
http://www.japantimes.co.jp/text/nb20130122n2.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+japantimes+%28The+Japan+Times%3A+All+Stories%29

[SeanB]

I would guess the same as what made so many laptop batteries flame, metal contaminants in the cell which eventually made it short....







-24.371211,31.039365

[Eliminateur]

Apparently it's not due to over-charging/over-voltage. So what else would cause a LiPo battery to burst into flames? Too much current perhaps?

too much current IS overcharging.
if it wasn't OV/OC, then it's either shoddy construction or the cells fail under the atmospheric conditions in the plane....

[Neilm]

Charging if the battery is too cold can cause lithium metal to coat the electrode. This will reduce the internal cell clearances and can cause a short circuit, leading to fire.

At least, that is what I got told by a rep who wanted me to use some very expensive cells in my last project as there was a requirement to charge below freezing. The must have requirement was dropped when they found out how much it would cost. 

Neil

[Skimask]

The ram air turbine will definitely need to be more than a few lights and a gyro on the 787. It would need to supply electrical power for the hydraulic and pneumatic systems.

Didn't say it was gonna be a _small RAT.
Ya, probably have to have enough juice to at least run the trim tabs, which I would think would be just barely enough to maintain control, a couple of fuel pumps to keep the mains full for gravity feed, the gear, probably a one time blown down off a bottle, and the list goes on..and on..and on.....