Laptop ban coming soon?
#11
Gets Weekends Off
Joined APC: Aug 2008
Position: 777 Left
Posts: 347
The TSA says laptops need to go into the hold (from some countries) now FAA says they should not go into the hold. So what is the PAX supposed to do? Leave home without his laptop? Seems like the gov needs to get their message right - people will just stop flying if they cannot actually arrive and do business.
#14
I know you jest...but the crux is, halon doesn't work on Li battery fires. Halon works in conventional fires by displacing oxygen. Lithium batteries are self-oxidizing.
Lithium batteries are popular for one reason: they have the highest energy-density you can get in a battery.
The problem with packing a lot of energy in a small space: regardless of the energy source, this has the potential to be a "bomb." Gas in a can, tritonal in a steel case, Semtex, or Lithium paste in a battery.
The solution really should be what they did with the 787 after ITS Lithium battery fires: they put the battery in a steel containment box. The Litium fire can't breach the box, but it gets hot. The box is thermally isolated to prevent contact fires on the outside.
Personally, I'd like to see a small steel baggage pod for Li-powered devices.
Cargo fires have always worried me. Read the transcript of UPS 6, and you will wonder how politicians can value revenue over life.
Lithium batteries are popular for one reason: they have the highest energy-density you can get in a battery.
The problem with packing a lot of energy in a small space: regardless of the energy source, this has the potential to be a "bomb." Gas in a can, tritonal in a steel case, Semtex, or Lithium paste in a battery.
The solution really should be what they did with the 787 after ITS Lithium battery fires: they put the battery in a steel containment box. The Litium fire can't breach the box, but it gets hot. The box is thermally isolated to prevent contact fires on the outside.
Personally, I'd like to see a small steel baggage pod for Li-powered devices.
Cargo fires have always worried me. Read the transcript of UPS 6, and you will wonder how politicians can value revenue over life.
#15
Once you a have a full hull loss of a large pax jet due to a Li battery fire in cargo, then something will have to give. It will probably be an over-water flight, with drawn-out drama. They'll make a movie about it eventually.
#17
#18
Technically, no.
Metal fires still need O2 but they burn so hot that they are just hard to put out (also hard to start). In some cases they can be hot enough to cause nearby compounds to break down and provide an oxidizer to support the fire in the absence of air. Oxygen is not the only potential oxidizer, especially if you have enough heat.
Li battery fires actually have two things going on...
The chemical energy stored in the battery is released via a short-circuit, generating a lot of current and therefore a lot of heat. This heat causes anything nearby to burn, including the battery compounds and adjacent cells, which then of course trigger a chain reaction as long as there are more batteries close by.
You can't really extinguish it, you just have to keep it cool while it discharges it's energy.
A large number of batteries (ie commercial shipment) would not be controllable once it gets going. Requirements to ship batteries with a lower state of charge reduce the risk.
Metal fires still need O2 but they burn so hot that they are just hard to put out (also hard to start). In some cases they can be hot enough to cause nearby compounds to break down and provide an oxidizer to support the fire in the absence of air. Oxygen is not the only potential oxidizer, especially if you have enough heat.
Li battery fires actually have two things going on...
The chemical energy stored in the battery is released via a short-circuit, generating a lot of current and therefore a lot of heat. This heat causes anything nearby to burn, including the battery compounds and adjacent cells, which then of course trigger a chain reaction as long as there are more batteries close by.
You can't really extinguish it, you just have to keep it cool while it discharges it's energy.
A large number of batteries (ie commercial shipment) would not be controllable once it gets going. Requirements to ship batteries with a lower state of charge reduce the risk.
#19
That said, I know of no airline that carries liquid nitrogen fire extinguishers.
#20
Metal box full of water, throw it in, close the lid and let it burn... sorry about your iTunes songs buddy. The large volume of water would be enough to compensate for the heat. Unfortunately this doesn't work for the cargo hold unless we start transporting blue wales in the hold like some Star Trek IV level stuff. Dang wales and their PEDs...
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