paranoid ?
in [ASM]
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From: Rod Pemberton on 21 Jan 2008 06:04 "Robert Redelmeier" <redelm(a)ev1.net.invalid> wrote in message news:K3Vkj.686$hI1.112(a)nlpi061.nbdc.sbc.com... > Rod Pemberton <do_not_have(a)nohavenot.cmm> wrote in part: > > "A","B","D","E", are all documented to occur. So, they > > aren't "strawmen" by any means. > > Please look up what a strawman is. "A straw man argument is an informal fallacy based on misrepresentation of an opponent's position." - Wikipedia > I was arguing against > firearms, or at least for requiring frangibles and mentioned > hoop failure. Instead of addressing this, I addressed this. I asked why you thought frangibles were required. You never replied to that. Am I to assume you desire frangibles to prevent longitudinal tears and blowout of the metals, potentially fatigued, which create a pressurized vessel? Why that'd be putting words into your mouth... You responded with "hoop failure" to "The plane is not going to explode if punctured.", not frangibles. And, you in no way indicated that you might believe that a "hoop failure" was less likely to occur when using frangibles. Given a "much shallower angle" of incidence, my first thoughts - without knowing much about frangibles - is that they'd skim the surface without puncturing it much like a regular bullet or rock skipping on a pond. Since very little of the bullet's kinetic energy would be applied to the frangible in such a situation, I'd question whether or not a frangible would disintegrate properly. And, my second thoughts regarding frangibles is, "Just how much impact is required to disintegrate one?" It's possible the frangible will go right through the thin aluminum skin, although the plastic wall coverings inside the skin the plane might stop them or not. And, my second thoughts are some frangibles aren't force sensitive, but temperature sensitive: "So, which type is he talking about?" Anyway, I'm still unclear as to why you support the use of frangibles. > you then accused > me of losing interest and proffered your strawman agruments. > I proffered valid reasons why frangibles could be required since it appeared to me you hadn't. If you thought you already stated why, you could've said so. But, in no way could those reasons from me ever be "an informal fallacy based on misrepresentation of an opponent's position" because your position was never explicitly stated... > > Did you intend to offend? I took offense. > > ... do you think putting words into someone else's > mouth is not cause for at least some caustic remarks? > That's a misrepresentation... > [...] it's [shooting the wires] probability (steradians of vulnerability) is much lower > than hull strike. > It's obvious that a bullet has a higher percentage chance of striking and puncturing the plane's skin than wires - which is all you've stated, AFAICT. And, yet, you still make no claim as to which, "hoop failure" due to "hull strike" by bullet or an electrical short by bullet causing a CWT explosion, has a higher or lower probability of causing a dangerous failure. A puncture of the skin does not guarantee a "hoop failure." Rod Pemberton
From: Robert Redelmeier on 21 Jan 2008 09:03 Rod Pemberton <do_not_have(a)nohavenot.cmm> wrote in part: > I addressed this. I asked why you thought frangibles > were required. You never replied to that. No, I posted upthread, you received and quoted: >.> Only for fairly small round holes. Misses likely would hit the >.> pressure hull at a much shallower angle, resulting in a longer >.> tear and potential hoop failure, especially in the fatigued >.> aluminum you perviously mentioned. At least one aircraft >.> has suffered such a failure in flight without the hole. > Am I to assume you desire frangibles to prevent longitudinal > tears and blowout of the metals, potentially fatigued, > which create a pressurized vessel? Why that'd be putting > words into your mouth... No assumption, because I posted exactly that and you even quoted it. > Anyway, I'm still unclear as to why you support the use of frangibles. I'm not sure I do, but if any ammunition is, it probably should be frangibles. Glasers are one brand that was specifically designed for use in aircraft in the 1960s. Essentially these are canister rounds -- a very thin bullet shaped can holding small shot in oil. The can might be able to penetrate light clothing intact but probably not 3mm plastic. > > It's obvious that a bullet has a higher percentage chance of striking and > puncturing the plane's skin than wires - which is all you've stated, AFAICT. > And, yet, you still make no claim as to which, "hoop failure" due to "hull > strike" by bullet or an electrical short by bullet causing a CWT explosion, > has a higher or lower probability of causing a dangerous failure. Hoop stress is the governing stress on cylindrical pressure vessels. Since striking wires is far less probable, I'm not much worried about it. Fuel ignitions do not worry me much. Jet fuel has a flash point (IIRC, PMCC) of 140'F and ought to be able to _extinguish_ sparks below a certain size. Yes, fires have occurred, but AFAIK, always associated with overheated fuel above 140'F from AC units dumping heat into the CWT when underfilled.. > A puncture of the skin does not guarantee a "hoop failure." Of course not. It all depends on where and what angle. But in the absence of a more detailed study, this seems to me to be the greatest single risk of total aircraft loss from a single internal bullet strike. Why do you think on-board explosives are so deadly? Why aren't they like train bombs? -- Robert
From: Rod Pemberton on 21 Jan 2008 16:23 "Robert Redelmeier" <redelm(a)ev1.net.invalid> wrote in message news:qC1lj.66900$eY.34723(a)newssvr13.news.prodigy.net... > Why do you think on-board > explosives are so deadly? Why aren't they like train bombs? > They're usually placed over the fuel tank. IIRC, military planes have nitrogen (instead of air) in the fuel tank, and so the vaporized fuel can't cause a fire or be used as an explosive. In the fuel tank there is a mix of a volatile fuel and oxidizer (20% of air as oxygen). Let's look at other combinations of a volatile fuel and an oxidizer: ammonium nitrate and fuel oil, ammonium perchlorate and aluminum, fertilizer or grain dust or coal dust and oxygen, etc. I'm not sure about airplane fuel oil, but for gasoline the energy released increases exponentially with compression. The chart I saw many years ago on gasoline energy release vs. compression went upto an 18:1 compression ratio. The chart didn't say if it was regular commercial gasoline or high octane racing fuel. If better materials were available when the chart was produced, the chart probably would've gone much higher. Essentially, gasoline is capable of bomb like energy releases without increasing the percentage of oxydizers (20% for air) to the mix, such as nitrous oxide (33% oxygen) or pure oxygen. Gasoline is also known to release more energy with a slight amount of water or moisture. This has been used in automotive engines and is usually a factor in the cause of gas explosions. The exponential energy release of gasoline at high pressures, and "safer" flamability at low pressures is a primary reason why other "bomb-like" energy sources like C4, etc. for engines. (The others are current cost and gov't regulation.) "Gas tanks" will be much bigger for hydrogen, compressed air, hydraulics, batteries, or any other form of energy storage used to propel vehicles. They just don't have a comparable energy density. The only realistic way out, IMO, is electrons via superconductors and high energy density capacitors - neither technology is mature enough. Rod Pemberton
From: Evenbit on 22 Jan 2008 13:34 Robert Redelmeier wrote: > > Anyway, I'm still unclear as to why you support the use of frangibles. > > I'm not sure I do, but if any ammunition is, it probably should > be frangibles. Glasers are one brand that was specifically > designed for use in aircraft in the 1960s. Essentially these > are canister rounds -- a very thin bullet shaped can holding > small shot in oil. The can might be able to penetrate light > clothing intact but probably not 3mm plastic. Horse manuer! The Glaser design is a known "armour-piercing" "cop-killer" bullet. Politicians used it as an excuse to push for more restrictions on arms imports/civilian access. Nathan.
From: Evenbit on 22 Jan 2008 13:47
On Jan 19, 4:10 pm, "Rod Pemberton" <do_not_h...(a)nohavenot.cmm> wrote: > "Evenbit" <nbaker2...(a)charter.net> wrote in message > > news:e9c9170c-3c33-4a55-bdff-0c710d285930(a)v46g2000hsv.googlegroups.com... > > > On Jan 18, 9:25 pm, "Rod Pemberton" <do_not_h...(a)nohavenot.cmm> wrote: > > > > I agree. Why does everyone seem to think I mentioned a .45? > > > Because it is the absolute minimum one needs for effective self- > > defense. Anything less is useless... you might as well be carrying a > > beebee gun, paint gun, or water pistol. > > I agree that .45 is the best available pistol round for self-defense, but I > beg to differ with it being the "absolute minimum." I personally believe > .308 Winchester is the rough minimum required for _effective_ self-defense. Please remember that within the definition for "effective" the term "reliable" is implied. You do not want to take the chance of the "bad guy" standing up again. > > I have a fairly large family. I haven't met most of them, but, due just to > size, one can assume that there are both cops and crooks. If one or the > other from my own family shows up on my doorstep, it's likely they'll be > wearing a vest since I don't view them as poor, stupid, etc. That means, > without taking into account non-family elements of society, I need to be > able to "pop" a vest for realistic home or personal defense. Now, given No. The requirement of >= .45 is not for "popping" a vest. If the "bad guy" is "spaced-out" on drugs, he can likely ignore a small wound from a smaller weapon and will continue the attack -- and be more determined to succeed this time. Using a .45 or .50 will increase the odds that he will stay on the floor. Nathan. |