lomapaseo

you write....

"I'm still not clear what the critical safety issue is that caused the grounding of this fleet."

You must have not read the Airworthiness Directive..... The FAA seem pretty clear.

You read it? Then are you second guessing the RA (Regulating Authority)? As in hand as FAA are, one would expect it took more evidence than necesssary to ground, not less?

Clarify?

Complex situation
 

lomapaseo

The issue has a lot of components:

1) Safety of planes
2) Technical (What is the problem?)
3) Economic (in a difficult moment for US)
4) Influence to Boeing (Relies on 787)

IMO FAA is acting too politically. It seems aggravating the issue. But they should have info we don´t. The name "Lithium battery" is tainted. And everybody relies on these batteries. There are many types, some even more dangerous, like Li Po.

FAA is near the center of a big storm. The eye (volatile) moving; a storm with lightnings capable to hit all players. :sad:

when something bursts into flames that ain't supposed to I think that's a critical safety issue - especially when you look at what happens when aircraft DO catch fire in flight.............

Where is the problem? Forget Li Po for now
 

hetfield:

We cannot say this happened. First of all the Li Po are not being used in the Av industry.The planes transport every day, thousands (not being recharged, :)) with no reasons for alarm. And AFAIK, most laptops don´t use Li Po.

So, we must concentrate on the problem now: Li Ion that were used (in the past, :}) in 787 and the continued use, RIGHT NOW on the fleet of A380.

Question: Li Ion in A380 are being kept "floating" by A/C?

It seems EADS could be affected too. :{

The FAA/NTSB have not released any technical details of their specific concerns which led to the 787 fleet being grounded. It seems very unlikely that they would ground these aircraft due to the non-availability of electrical power from a battery. My guess it is fire damage (either actual or potential) to critical electrical systems within the EE bay that is the real worry, and the reason for the grounding.

The fire on the 787 in Boston was tackled by airport fire services very quickly and the fire on the ANA aircraft happened shortly after it departed Haneda airport. In both cases, it was possible to extinguish the fires reasonably quickly after their detection. However, the FAA will need to consider what fire damage might result to critical systems from a similar battery fire in mid-Atlantic, at 40,000'.

Do you remember the 747F Dubai(?) crash?


wiki

RR_NDB
 

After more than five years of A380 commercial service, we still need to see a battery related incident as serious as those witnessed on the 787.
This thread is addressing 787 batteries ... not A380 batteries.
So if you would like to address this matter, please open a dedicated thread.

@Avionista: It took 40 min to distinguish the Boston fire - this was not an easy task.

In my upper linked article of the Seattle Times Boeing rumours to be indignant about FAA´s acting. For Boeing the 787 ist still safe to fly. I can´t belive this careless behaviour. To have a malfunction in a product is one side, to ignore the risks another. Think this is no good PR for the reputation of Boeing.

On the other side the FAA seems faced a difficult situation. Once there will increase the pressure of commercial interests. But easing the situation and relase the 787 back to service before a real solution is on the table, will push the upcoming discussions they´ve been to rigorous with the grounding.

For me they did the only right thing: In aviation "safety first".

A fire breaks out on a couple of a/c. Neither the manufacturer of the battery, charger or a/c know why.
That seems to be good enough reason to ground it.


Posted from Pprune.org App for Android

Reasons for 787 grounding
 

hetfield,

Yes! Since few minutes after the crash i am looking to the issue: The danger Lithium batteries poses to us.

AFAIK UPS 744 was not transporting Li Po batteries nor using Li Ion batteries.

We are concentrated on li Ion and not Li Po, llagonne66

This thread is addressing 787 grounding.

The same type of battery is in operation right now in just one other type: The Airbus 380. The mention to this fact is pertinent to the discussion on the reasons of 787 grounding specially because FAA put the battery* at the focus.

i am concentrated on the 787 issue (battery selection are important to me as a designer) and may be your suggestion could be accepted by someone interested to create another thread.

(*) And the problem can be not exactly with the battery (chemistry) technology.

Yes, but both are popular for overheat/fire....like we all know now!

"...the National Transportation Safety Board said an examination of the data from the plane’s flight recorder indicated that the battery “did not exceed the designed voltage of 32 volts.”

I do hope the NTSB was not trying to say there was no overvoltage problem because the external voltage was below the 8 cell limit.

Many technical reports about the batteries in question note that external charging voltage is no indication of cell to cell voltage. Those reports document cases of individual cells having excessive internal resistance which raised their internal voltage and leads to thermal runaway in that one cell.

The thermal damage then spreads to adjacent cells.

Most technical reports on safety and these batteries point out the need to monitor individual cell temperatures and to control the external voltage and current based on the worst performing cell.

Lithium Ion battery concerns
 

TURIN

Quote:

---

That seems to be good enough reason to ground it.

---

The use of Li Ion batteries on airliners is under investigation. This should be enough to make other authorities to address the issue.

Important to differentiate the cells to the battery:

E.G.

The 787 battery is made by Thales using cells from Yuasa.

AFAIK the battery used in A380 emergency lightning comes from SAFT. The details will be commented in another thread.

TacomaSailor,

Important issue:

"individual cells having excessive internal resistance which raised their internal voltage and leads to thermal runaway in that one cell."

I will go further: You need to monitor ea. cell voltage AND temperature, during charge AND discharge. This is critical (safety) and important for longer life. I (strongly suspect) have serious objections how they are using the cells.

The safest would be to separate them (redundantly) electrically and physically. This will be addressed in 787 Batteries and Chargers

Risks of this wonderful and dangerous batteries
 

hetfield,

Some 3 years ago i discussed with a major airliner CEO a dangerous scenario of smokes in an overhead bin due a laptop battery failure and the CC training for that.

The video you posted is important to remember us to be proactive on the issue. Indeed a lot of pax and crew are transporting it (not being recharged, fortunately) in A/C.

Rgds,

RR, A380 and Li
 

Re RR_ndb
haha, the problem on the 380 were the RR, not the batteries :):)

Exciting experiences
 

golfyankeesierra,

The mix of Li Ion and RR indeed is :mad:

:{

Horror movies
 

golfyankeesierra,

Some years ago i was sleeping when the Ni Cd pack of my motorola vehicular caught fire whilst being recharged. Still "sleeping" i separated the pack from the unit burning slightly one finger. The pack was protected thermally and electrically but the adjacent cells (like VC10, B52, Nimrod, dangerous engines config.) were the factor of the complete destruction of the pack.

I strongly suspect the designers of these batteries are playing a very dangerous game. And the toll yet was paid by Boeing.

More to come, :sad:

In my electric bike i yet installed an APU of 300W. The battery is just for lighting and motor-gennie start.

NTSB: Excess battery voltage ruled out in 787 fire | HeraldNet.com - Work

the Herald.net article states:

. Interesting concept. The FAA does not instruct the OEM how to comply... that is the OEM's job to show compliance, or an equivalent safety finding, or to justify a special conditionbeing approved by the RA.

The B787 Type Certificate FAA TCDS T00021SE/EASA.IM.A.115 section 5, Special Conditions, has certificate review item (CRI) F24, Lithium Ion Batteries which is the area of interest at present. Would think that the FAA would be disinclined in accepting on face value the assumptions of fitness for service and risk analysis (25.1309) on a basis consistent with the good old risk matrix (MIL STD 882D).

"Boeing said last week it won't deliver more 787s until the U.S. Federal Aviation Administration instructs it on how to prove the Dreamliner's flammable lithium-ion batteries are safe."


Whatever the source of the quote, if Boenig is doing that, it is in contravention of the AD, as the FAA state clearly the company itself must "demonstrate the battery system is safe". They also require 'methods and materials' to be submitted by the OEM to the ACOM. Boeing cannot possibly be painting themselves as a "victim": "show us what to do?" Could their public position be that childlike?

The Lithium install violated virtually all of the considerations required by FAA from the git..

"AD Requirements
This AD requires modification of the battery system, or other actions, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA."