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Forum: Rumours & News

26th Mar 2013, 16:07

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

Following FullWings's post

My understanding is that any oxygen recombines with the anode material as it is produced, with heat and non-combustible byproducts; if the anode is graphite, which I conjecture is the case, that...

Forum: Rumours & News

25th Mar 2013, 10:42

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

Cells redesigned, or NOT?

Blacksheep wrote:
However Boeing is quoted as:
that's here
787 Ferry Flights To Resume (http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_03_25_2013_p35-561498.xml&p=2)

If there is a...

Forum: Rumours & News

20th Mar 2013, 14:28

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

@OpenCirrus619: do not underestimate Boeing

Don't be so sure Boeing has not identified the cause, or at least some likely cause(s).

I think they have clues, but prefer not to tell, partly because they are not quite sure it is cell damage by...

Forum: Rumours & News

20th Mar 2013, 07:07

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

Beyond damage control

Boeing is trying some damage control redefining "thermal runaway" and "fire".

My understanding of the reaction that occurs during thermal runaway (which, that's undisputed, did occur at the cell...

Forum: Rumours & News

18th Mar 2013, 10:38

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

About "deep discharge"

I'm still looking at where "deep discharge" was originally used by Boeing. Tried browsing that video for an hour, but missed it. Pointers welcome!
Webcast - Boeing 787 Updates...

Forum: Rumours & News

17th Mar 2013, 10:00

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

Deep discharge of a single cell presented as a probable cause of the fire

Source: report on a Boeing presentation
Boeing outlines fix for 787 batteries ? The Register (http://www.theregister.co.uk/2013/03/15/boeing_787_fix/)

Seems not unreasonable to me. Deep discharge...

Forum: Rumours & News

16th Mar 2013, 12:16

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

Definition of thermal runaway

To an engineer, thermal runaway is when temperature elevation triggers something with the effect of releasing energy, further increasing temperature, leading to a self-sustaining positive feedback...

Forum: Rumours & News

15th Mar 2013, 09:37

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

From a Boeing press release

Source: subscription to Boeing media alerts, see
The Boeing Company: Commercial Airplanes - 787 (http://www.boeing.com/787-media-resource/)(..)
The first layer of improvements is taking place...

Forum: Rumours & News

13th Mar 2013, 07:19

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

Quoting the FAA Press Release – FAA...

Quoting the FAA
Press Release – FAA Approves Boeing 787 Certification Plan (http://www.faa.gov/news/press_releases/news_story.cfm?newsId=14394)

> The battery system improvements include a...

Forum: Rumours & News

8th Mar 2013, 17:29

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

State of the main battery?

In their interim report, section 1.5.4, the NTSB reports having made Computed Tomography (CT) scans of both the APU battery that burnt, and "the main battery (that) was used as an exemplar battery...

Forum: Rumours & News

5th Mar 2013, 16:36

Replies: 2,185

FAA Grounds 787s

Views: 1,032,258

Posted By fgrieu

Lithium batteries (when charged) do not need...

Lithium batteries (when charged) do not need extra oxygen/oxidizer to burn; they contain it, much like explosives do.

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