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-   -   FAA Grounds 787 in the US (https://www.airlinepilotforums.com/safety/72418-faa-grounds-787-us.html)

Phantom Flyer 01-18-2013 04:51 PM

Not an Engineer
 

Originally Posted by MrDK (Post 1333273)
Why jump two generations of battery back when one will do?
Absolutely no reason to entertain NiCad batteries when NiMH will do.
Besides, most (no-mechanical) Li-Ion hazards are related to the charging circuits and not the battery itself (knowing its limitations).
Why would anyone consider NiCad over NiMH ,,, in any environment?

First of all, I'm not an electrical engineer and limited in my ability to discuss the advantages/disadvantages of NiCad vs. NiMH vs. lithium batteries. I'll certainly agree that most of the issues with lithium-ion have been in the charging systems and not the battery itself. The problem is when a fault occurs and an overheat or charging malfunction creates a fire, we have one serious problem. In flight, it could easily be a catastrophe.

I think that Boeing engineers were trying to save weight as well as provide batteries with a quicker re-charge time and larger capacity in selecting lithium-ion. After all, this aircraft is not only an "electric aircraft", it takes that concept to a new level. Any engineers on the forum please correct me if I'm wrong. The bottom line is that the containment box, no mater how well designed probably will not completely contain a lithium fire and therefore an extinguishing agent must be developed that will actually extinguish a lithium fire in-flight. Until that can be demonstrated, there is a risk in operating the 787. Obviously the FAA felt the same way.

I fly RC aircraft and the lithium-polymer batteries are commonly used. I have seen a li-po battery fire and it's not a pretty sight. Keep in mind, this was in an RC aircraft.

Y'all be careful out there !:)

MrDK 01-21-2013 12:31 AM


Originally Posted by FlyJSH (Post 1333282)
I'd rather go back to lead acid. NiCads and MiMH can both go into an overcharged/overdrawn/overheated state that can lead to venting or fire. Lead acid generally do not (without actually throwing them into a fire).

Also, the nice thing about lead acid is they tend to fail slowly and have a more measurable output drop (they give warning when they are getting weak while NiCads and NiMHs do not).

If weight, charge time and heavy duty cycle are not an issue then lead acid out performs them all. They, however, take proportionally much longer to charge, quickly fail if deep discharged and weigh 'a ton'.
I do not know how many pounds of Li-Ion batteries are part of the 787 design. Adding a couple of hundred of pounds for another technology would amount to just one more average male passenger.
Whatever Boeing chose as their option it is not just a matter of changing the batteries, all elements relating to the charging circuit and the monitoring thereof need to be changed as well.

Snarge 01-21-2013 07:30 AM

If you want to be the worlds leading airline, you need to have the worlds leading aircraft.... -Jeff S.

Phantom Flyer 01-21-2013 04:57 PM

A Lot of Incidents
 

Originally Posted by Moby Dick (Post 1333296)
Lithium ion batteries are a huge fire hazard. You cannot carry them on passenger airplanes if you're shipping them. They are "Cargo Aircraft Only" hazmat.

AINSafety today (1/21/13) printed a report stating that since March 20, 2012, there have been 132 incidents of either an overheat or fire involving lithium-ion batteries in the U.S. Most of the reported incidents occurred in either a cargo aircraft (makes the freight dogs wag their tails) or with passenger personal devices. The JAL Dreamliner fire at BOS is the latest exception. That's a LOT of incidents in less than four months.

Y'All be careful.:)

threeighteen 01-21-2013 06:16 PM


Originally Posted by Snarge (Post 1335189)
If you want to be the worlds leading airline, you need to have the worlds leading aircraft.... -Jeff S.

So who wants to pick straws to tell him that the Concorde has been grounded for nearly 10 years? :p

MrDK 01-21-2013 11:46 PM


Originally Posted by Phantom Flyer (Post 1335474)
AINSafety today (1/21/13) printed a report stating that since March 20, 2012, there have been 132 incidents of either an overheat or fire involving lithium-ion batteries in the U.S. Most of the reported incidents occurred in either a cargo aircraft (makes the freight dogs wag their tails) or with passenger personal devices. The JAL Dreamliner fire at BOS is the latest exception. That's a LOT of incidents in less than four months.

Y'All be careful.:)

Let's get the calculator out!

Snarge 01-22-2013 04:02 AM

Sounds like the Dreamliner might be the junior new hire's 'choice' at CAL......

Phantom Flyer 01-22-2013 06:28 PM

It Adds Up
 

Originally Posted by MrDK (Post 1335620)
Let's get the calculator out!

I had a friend read the article and do the math while another acquaintance who works for Price Waterhouse, also ran all of the numbers through their computers. Both agreed. Since March 20, 2012, there have been 132 incidents leading to either a serious overheat or a fire with lithium-ion batteries as per the report. By my calculations, that equates to 132 events in slightly over ten months.

Have some sake and chill out Mate.:)

threeighteen 01-23-2013 06:23 AM


Originally Posted by Snarge (Post 1335646)
Sounds like the Dreamliner might be the junior new hire's 'choice' at CAL......

Junior? If this keeps up, it's going to be as senior as it gets. Essentially get paid to hold a line that you don't have to work...

JP1234 04-23-2013 04:32 PM


Originally Posted by threeighteen (Post 1336614)
Junior? If this keeps up, it's going to be as senior as it gets. Essentially get paid to hold a line that you don't have to work...

Has anyone seen the "update"?


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