Ban on Lighters
Apr 15th, 2005, 06:31 AM
#21
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> Butane lighters contain about 350 cubic feet of explosive gas. If you took that lighter into the lave, broke it open, filled the space with butane and lit it with a match, it would blow the airplane's tail off. <
I did some back-of-the-envelope calculations using assumptions regarding the volume of butane (it's actually a butane/propane mixture, but that's a fine point) in a lighter (5 ml), the volume of an airliner lavatory (4 m**3), the molecular weight of butane, the ideal gas law, and the lower explosive limit of butane as specified in the MSDS, and I don't think it's possible to do what you're suggesting. I come up with a concentration of butane in the air that would be only about 10% of that needed to cause an explosion. Admittedly I didn't account for the lower pressure in the cabin, but if anything I think that would make an explosion even more difficult due to decreased partial pressure of oxygen. There are a lot of numbers and unit conversions in the calculations, so I'm prepared to be convinced otherwise - do you have any reference to a credible source that would support such a scenario?
I did some back-of-the-envelope calculations using assumptions regarding the volume of butane (it's actually a butane/propane mixture, but that's a fine point) in a lighter (5 ml), the volume of an airliner lavatory (4 m**3), the molecular weight of butane, the ideal gas law, and the lower explosive limit of butane as specified in the MSDS, and I don't think it's possible to do what you're suggesting. I come up with a concentration of butane in the air that would be only about 10% of that needed to cause an explosion. Admittedly I didn't account for the lower pressure in the cabin, but if anything I think that would make an explosion even more difficult due to decreased partial pressure of oxygen. There are a lot of numbers and unit conversions in the calculations, so I'm prepared to be convinced otherwise - do you have any reference to a credible source that would support such a scenario?
Apr 15th, 2005, 08:27 AM
#22
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I guess we'll just have to compare envelopes some time. The reality is that gas lighters have been prohibited from checked baggage for 30 years because of the potential for leakage and explosion in a confined space. This was never thought to be an issue in the passenger cabin because of its much greater volume. But now that we are under attack, the risk of ignition in a lavatory is considered significant.
Apr 15th, 2005, 09:03 AM
#23
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No, they've been prohibited, along with many other flammable materials, because they would act as accelerants, not due to fear of explosion. And yes, I'm sure you could probably go into a lavatory and manipulate a lighter to create a pretty impressive fireball. But that's not an explosion and it's not going to damage the structure of an airframe (and certainly not blow the tail off), which is what you claimed. A true explosion requires that the butane concentration in an enclosed space somehow be controlled to between about 1.8% and 9.5% butane, then ignited. As I said, I don't think the 3 grams or so of butane in a lighter is enough to reach the 1.8% in the space of an airplane lavatory.
Apr 15th, 2005, 09:20 AM
#24
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I don't get that. If gas lighters were banned from baggage because they were accelerants, why wouldn't the same prohibition apply to those carried by passengers, and for the same reason?
Between the rapid production of combustion gases and pressure increase caused by heating, I think the overpressure produced by even a small gas explosion is enough to blow out the side of a typical fuselage.
Between the rapid production of combustion gases and pressure increase caused by heating, I think the overpressure produced by even a small gas explosion is enough to blow out the side of a typical fuselage.
Apr 15th, 2005, 09:42 AM
#25
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Whilst it's all very well banning lighters, I wonder how it can be enforced.
Steel ones never show up when you walk through a security scanner affair, so as such they've no idea that you're carrying one. Furthermore, if one had a gold/silver one it most certainly wouldn't show up even with those handheld wands. My point being that if a terrorist is determined enough to take something onboard an aircraft that is pocket sized then they'll find some way of doing it. Recently there was an item in the news about a gun disguised in a keyring that fired two cartridges - albeit inaccurately - that would be effective at point blank range. Bans are merely in place for public confidence, and serve little in effective security. Just look at speed limits and every single driver will have broken them on a regular basis or at least once - they're not much of a deterrent.
Steel ones never show up when you walk through a security scanner affair, so as such they've no idea that you're carrying one. Furthermore, if one had a gold/silver one it most certainly wouldn't show up even with those handheld wands. My point being that if a terrorist is determined enough to take something onboard an aircraft that is pocket sized then they'll find some way of doing it. Recently there was an item in the news about a gun disguised in a keyring that fired two cartridges - albeit inaccurately - that would be effective at point blank range. Bans are merely in place for public confidence, and serve little in effective security. Just look at speed limits and every single driver will have broken them on a regular basis or at least once - they're not much of a deterrent.
Apr 15th, 2005, 03:15 PM
#32
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On each Europe trip I stop at a tabac for a handful of Bics and bring them back to the US. European manufactured lighters don't have the childproof features required by those made in the states.
This matter is as lidicrous as believing that a terrorist will learn how to blow up a plane by reading the dialog above. Would a match and a can of hairspray not be more threatening?
This matter is as lidicrous as believing that a terrorist will learn how to blow up a plane by reading the dialog above. Would a match and a can of hairspray not be more threatening?
Apr 15th, 2005, 03:19 PM
#34
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I don't see it as a huge issue. I'm a smoker, sure its a bit of a pain...but putting a book or two of matches in my carry-on till I reach my destination and able to buy a disposable lighter sometime after arrival is no big deal.
I just certainly hope that passengers thinking they'll get around the ban by putting them in checked luggage doesn't happen. While we know lighters or any other kind of flamable items are banned and have been banned in checked luggage, and or good reason, certainly not a security reason its pure safety and common sense.
I just certainly hope that passengers thinking they'll get around the ban by putting them in checked luggage doesn't happen. While we know lighters or any other kind of flamable items are banned and have been banned in checked luggage, and or good reason, certainly not a security reason its pure safety and common sense.
Apr 15th, 2005, 03:22 PM
#35
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Thanks, Robert Reid! Doofus #1! and while we are at it, how about this thing about taking off shoes at security? When ONE person ONE time can invert to fabric of society so completely, things are really whacked!!! OK, enought of this thread!
Apr 15th, 2005, 03:27 PM
#36
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I quite agree with the hairspray thing, also it's with far more pressure than a lighter could ever have and a vastly greater volume. The authorities never see sense.
My favourite incident is being refused razor blades through security, only to be able to buy them in the chemist past the security...how inconsistent.
My favourite incident is being refused razor blades through security, only to be able to buy them in the chemist past the security...how inconsistent.
Apr 15th, 2005, 03:45 PM
#39
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To answer the question as to why a smoker on a nonsmoking flight would need a lighter....well quite simply to light up after leaving the terminal. Of course, matches work too....as I said its not a big deal.
I don't understand the responses going back and forth about lighters in checked luggage vs. carry-on cabin from the wannabe scientists on this thread. It has not one thing to do with any of that, it is just simple common sense. You put a flammable item in an inaccessible area and a fire starts...not a good thing, albeit unlikely being unpressurized...lack of oxygen to feed it vs. in the cabin area where it would more easily ignite however be dealt with and more importantly realized immediately....it certainly wouldn't blow the tail off, would cause some bad burns to anyone nearby. Silly issue.
For hairspray (aerosol), thats been banned in checked luggage for the same reasons. To my knowledge safety razors are allowed in your carry-on unless they've changed that and I've just not been aware and somehow getting through with them.
Happy travels.
I don't understand the responses going back and forth about lighters in checked luggage vs. carry-on cabin from the wannabe scientists on this thread. It has not one thing to do with any of that, it is just simple common sense. You put a flammable item in an inaccessible area and a fire starts...not a good thing, albeit unlikely being unpressurized...lack of oxygen to feed it vs. in the cabin area where it would more easily ignite however be dealt with and more importantly realized immediately....it certainly wouldn't blow the tail off, would cause some bad burns to anyone nearby. Silly issue.
For hairspray (aerosol), thats been banned in checked luggage for the same reasons. To my knowledge safety razors are allowed in your carry-on unless they've changed that and I've just not been aware and somehow getting through with them.
Happy travels.
