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Splode posted:Ahh I knew I was missing something, thanks! I always forget about temperature limits and poo poo for electronics. Oh yeah, it should be noted that system manufacturers also do use commercial/industrial parts in mil stuff all the time, it's just the entire thing that has to pass MIL-STD-810 requirements. So regardless of where in the integration chain from component to finished system that gets fielded there is a lot of extra validation work getting done. A big reason why the prices are so much higher than comparable consumer stuff.
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Mar 3, 2016 09:29
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There's also the supply/demand issue. Who the hell else is ordering 1972ish electronics and laser equipment? How many manufacturers are even bothering? The answers are probably "nobody" and "one" respectively, so the price is whatever they want.
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Mar 3, 2016 09:36
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Yup exactly, and often a second source is required in case the first one's factory burns down so you're subsidizing two companies! Military procurement is like a hosed up socialism 
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Mar 3, 2016 09:42
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priznat posted:Yup exactly, and often a second source is required in case the first one's factory burns down so you're subsidizing two companies! national socialism, the best kind 
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Mar 3, 2016 09:44
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Splode posted:Military costs are so weird. Proportional control electronics are really not that expensive for civilian technology, but I guess when you make it out of of bald eagle tears it becomes outrageous?
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Mar 3, 2016 09:44
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evil_bunnY posted:That's probably related to the seeker and not the control package. Good point, if it's only 4 sensors you don't have really have enough data for proportional control.
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Mar 3, 2016 09:47
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priznat posted:Cool words Every single line of code is supposed to be vetted as well, right?
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Mar 3, 2016 10:38
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hobbesmaster posted:F-35 A, B, C. Don't be sad; 2 out of 3 ain't bad. Based on the report pointing out the F-35A's weapon bays are overheating so they have to be opened every ten minutes to cool off, and vibrating so much that the only thing they could get out of the test equipment put instead of actual missiles was that it was definitely outside of the flight envelope for a missile, I wouldn't be so certain the A and C are going to be that much better than the B. priznat posted:Military specifications can be pretty strenuous. For example electronics come in several grades including commercial (that is in most stuff), industrial (that is in stuff like a pulp mill or whatever) and military. I remember an article that worried about the increasing use of commercial off-the-shelf stuff in electronics, the gist was basically "Apple doesn't care if the processors in an iPod crap out and stop working reliably after five years, because all their customers will have long moved to newer models; but in the army it's important that components can work for several decades and with COTS, the ones old enough to have proved if they can work for decades are no longer being produced, and those being produced are too recent to have been tested for how long they last."
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Mar 3, 2016 11:58
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PittTheElder posted:that F-15 who scored an air-to-air kill with a bomb
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Mar 3, 2016 12:27
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Shazaminator posted:What?
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Mar 3, 2016 12:29
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Cat Mattress posted:Based on the report pointing out the F-35A's weapon bays are overheating so they have to be opened every ten minutes to cool off, and vibrating so much that the only thing they could get out of the test equipment put instead of actual missiles was that it was definitely outside of the flight envelope for a missile, I wouldn't be so certain the A and C are going to be that much better than the B. While a problem, you are oversimplifying and overstating this for dramatic effect.
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Mar 3, 2016 13:16
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evil_bunnY posted:Turns out it's p hard to outrun a laser designator guiding a bomb launched at fighter jet speed. The chopper was on the ground at release but took off, and the bomb splatted it anyway. That's beautiful. Is there anywhere we can read about the EF-111 that persuaded an Iraqi fighter to crash? Google isn't being helpful, or I'm not hitting the right search terms at any rate.
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Mar 3, 2016 13:18
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I'm guessing lovely Iraqi pilot training did most of the convincing.
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Mar 3, 2016 13:20
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Kesper North posted:That's beautiful. Dogfights did a segment on it when they did a show on the Persian Gulf.
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Mar 3, 2016 13:28
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Kesper North posted:That's beautiful. "ef-111 iraqi fighter crash ground" got tons of hits. Flikken posted:Dogfights did a segment on it when they did a show on the Persian Gulf. https://www.youtube.com/watch?v=WS60TCGzFnQ&t=70s
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Mar 3, 2016 15:27
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priznat posted:Military specifications can be pretty strenuous. For example electronics come in several grades including commercial (that is in most stuff), industrial (that is in stuff like a pulp mill or whatever) and military. I'm nothing like an engineer; for a long time I was that obnoxious guy in the room always saying WHY DON'T WE JUST USE A PC ILL BUILD YOU ONE OFF NEWEGG. I've unfortunately found myself neck deep in a couple of pretty major software/hardware updates/revisions and it has dramatically changed my perspective on these things. That isn't to say some of the requirements aren't silly, or that the process is streamlined or anything, but there at least typically is a reason for the ostensible silliness of some of this stuff.
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Mar 3, 2016 16:08
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Anything attached to a flying machine costs way more even if civilian. My brother worked at a place that did electronics for airliners. Not even avionics or flight control or anything. And it still took a ton of extra testing.
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Mar 3, 2016 17:21
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Ignition! Is a great if somewhat obscure book about rocket fuel development. During one section the authors team creates a great solid rocket fuel for air to air missiles only to have the Air Force point out that it had to be able to withstand storage from -50f (Thule AFB) to 120f (Nevada) and last 20+ years as opposed to a rocket that you were going to build and fire within a few weeks at most. Ignition! is available as a free pdf btw. Foreword by Issac Asimov. Smiling Jack fucked around with this message at 17:53 on Mar 3, 2016 |
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Mar 3, 2016 17:47
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Splode posted:Ahh I knew I was missing something, thanks! I always forget about temperature limits and poo poo for electronics. Don't forget "you can turn this on while it's surrounded by a cloud of fuel vapor and it won't make anything blow up" requirements.
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Mar 3, 2016 17:56
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This is a sweeping generality, but the reason aircraft parts are so expensive, never get redesigned, and have to be produced to a forty-year-old specification despite technology existing that could make them smaller, lighter, more reliable, and cheaper all at the same time is regulation. That part was originally certified to work in that configuration, and to change something would require recertification, which is obscenely expensive, so often you'll see aircraft running systems that are 30 years obsolete, because its cheaper to maintain a boutique-special-snowflake obsolete manufacturing line at ENORMOUS expense than it is to reengineer and recertify new parts and systems. Look up the Parts Manufacturer Approval process.  And that's only civilian stuff, that isn't literally hanging thousands of pounds of explosives on a couple bolts.
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Mar 3, 2016 18:02
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TheFluff posted:Promise and Reality: Beyond Visual Range (BVR) Air-To-Air Combat Decent read so far. This jumped out at me: quote:According to GWAPS, at least 20 of the 36 Sidewinder launches from F-16s were accidental. This was due to poor ergonomics on the joystick which was quickly modified.  I'd disagree with you that the reasons are political; I don't get that from this paper at all. In fact I think he goes to some length to demonstrate the reasons WVR has stayed are technical as well - how did you get to that conclusion? quote:Human factors, such as pilot skill—or the opponent’s ineptness—still trump technology. The only 'political' angle I see is the argument that training needs to be emphasized more; actually training the people in the cockpit because the human factor has been discounted due to people focusing on tech sheets instead of reality. I suppose the idea that they need to spend money on things like people instead of dumb poo poo from Raytheon would be a politicized statement  Psion fucked around with this message at 18:19 on Mar 3, 2016 |
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Mar 3, 2016 18:12
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Whoever came up with the name Sparkvark deserves a Medal of Honor. And man I wish Dogfights was still on, but I guess you start to run out of stories after a while.
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Mar 3, 2016 19:13
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Smiling Jack posted:Ignition! Is a great if somewhat obscure book about rocket fuel development. During one section the authors team creates a great solid rocket fuel for air to air missiles only to have the Air Force point out that it had to be able to withstand storage from -50f (Thule AFB) to 120f (Nevada) and last 20+ years as opposed to a rocket that you were going to build and fire within a few weeks at most. quote:It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.
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Mar 3, 2016 19:33
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Kesper North posted:That's beautiful. http://crossfade.io/#!/35jsvelcfd
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Mar 3, 2016 19:45
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Things I won't work with is great even if it is well outside your area of expertise
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Mar 3, 2016 19:50
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Helter Skelter posted:I ended up reading this a while back after one of my perusals of Things I Won't Work With. The anecdote on chlorine triflouride is a favorite: I had to look up a video for this stuff, and well,  https://www.youtube.com/watch?v=M4l56AfUTnQ
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Mar 3, 2016 19:53
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I love the compounds where he says things like " Yes, this is an example of something that becomes less explosive as a one-to-one cocrystal with TNT. Although, as the authors point out, if you heat those crystals up the two components separate out, and you’re left with crystals of pure CL-20 soaking in liquid TNT, a situation that will heighten your awareness of the fleeting nature of life." (from this one) and I'm not even going to copy and paste the name of that insane-rear end chemical also the phrase "Satan's kimchi" - referring to FOOF - is one that I'll always appreciate. Psion fucked around with this message at 19:59 on Mar 3, 2016 |
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Mar 3, 2016 19:54
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hogmartin posted:I'd have thought so, but it doesn't seem to have any actuating mechanism; in some videos it looks like it's weathervaning just from the wind coming across the deck. Best guess: Something something angle of attack (velocity vector bomb vs longitudinal axis of the bomb) something something? Fake edit: Hey, this post makes my guess was going in the right direction! iyaayas01 posted:Yup, the seeker on the CCG on a Paveway II isn't actuated in any way, it is "free-floating" and goes wherever the wind is pushing it when a bomb is sitting static on the ground.
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Mar 3, 2016 19:54
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One little addition to the conversation that also touches on the F-22 line restart: IIRC the CPUs driving its main avionics were discontinued by Intel/IBM in like 1996. That whole restart would be a lot more complex than just bending some titanium again.
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Mar 3, 2016 19:58
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Mazz posted:One little addition to the conversation that also touches on the F-22 line restart: IIRC the CPUs driving its main avionics were discontinued by Intel/IBM in like 1996. Sooo, the original Pentium?
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Mar 3, 2016 20:01
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Mazz posted:One little addition to the conversation that also touches on the F-22 line restart: IIRC the CPUs driving its main avionics were discontinued by Intel/IBM in like 1996. They were made until 2007 so thats a little bit later. But more importantly it was a dead end RISC architecture that ended up in only a few military projects.
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Mar 3, 2016 20:22
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Psion posted:I'd disagree with you that the reasons are political; I don't get that from this paper at all. In fact I think he goes to some length to demonstrate the reasons WVR has stayed are technical as well - how did you get to that conclusion? TheFluff fucked around with this message at 20:36 on Mar 3, 2016 |
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Mar 3, 2016 20:24
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Mazz posted:One little addition to the conversation that also touches on the F-22 line restart: IIRC the CPUs driving its main avionics were discontinued by Intel/IBM in like 1996. While a probably costly and difficult task it would be a task on the order of millions of dollars and thus pretty reasonable to overcome. If the source code is available just porting to a different processor would be pretty straight-forward. Yeah, sure there will be some modifications but nothing insurmountable. If the source code isn't available but Intel/IBM still have the masks you could probably just have a trusted foundy run off a few thousand at some not-unreasonable cost per part. Depending on the original process there may still be lines running that wouldn't even need modification. If the masks aren't still available and you don't have source code you could take the instruction set and redesign a functionally identical ISA. And then you could get into more elaborate solutions like virtual machines and what-not. Etc.., etc... Anyway google tells me the F-22 CIPS are Intel 960s which are still available. I could buy a couple of hundred of them off digikey this afternoon. e: Also, PowerPC isn't dead, it's in lots and lots of devices. e2: VVV A modified version of the Power architecture was used in the PS-3 cell processor... Murgos fucked around with this message at 20:56 on Mar 3, 2016 |
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Mar 3, 2016 20:45
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Murgos posted:e: Also, PowerPC isn't dead, it's in lots and lots of devices. Heh, the Wikipedia article says that quote:n 2003, BAE SYSTEMS Platform Solutions delivered the Vehicle-Management Computer for the F-35 fighter jet. This platform consists of dual PowerPCs made by Freescale in a triple redundant setup.
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Mar 3, 2016 20:47
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PowerPC lives on!
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Mar 3, 2016 20:54
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Miso Beno posted:PowerPC lives on! You scoff but it's widely used in fault tolerant applications. (Hence F-35 among others.) edit: https://en.wikipedia.org/wiki/IBM_POWER_microprocessors All modern Power architectures are actually derivative of the PowerPC instruction set. There is so much legacy code around that needs to keep running that there is no way that market is going anywhere. Plus new code gets written constantly, particularly for scientific and military projects. Murgos fucked around with this message at 21:03 on Mar 3, 2016 |
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Mar 3, 2016 20:57
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Murgos posted:While a probably costly and difficult task it would be a task on the order of millions of dollars and thus pretty reasonable to overcome. If you end up having to go with a different processor, how confident are you that it doesn't have errata, which can be as nasty as the Pentium fdiv bug? If you have to compile to a different architecture, how confident are you that you new compiler doesn't have bugs. That last 1% of certainty is ludicrously expensive.
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Mar 3, 2016 20:58
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Murgos posted:You scoff but it's widely used in fault tolerant applications. (Hence F-35 among others.) I'm not scoffing! I have an unreasonable love affair with PowerPCs. That's why I still have two Powermac G5s sitting under my healing bench at home. (also because I'm a horrible hoarder)
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Mar 3, 2016 21:00
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xthetenth posted:If you end up having to go with a different processor, how confident are you that it doesn't have errata, which can be as nasty as the Pentium fdiv bug? If you have to compile to a different architecture, how confident are you that you new compiler doesn't have bugs. It's not 100's of millions expensive though. So if your talking about a mulit-billion dollar project like reopening the F-22 line it would be in the noise. Anyway, as I said above the PowerPC ISA is still widely used, I doubt you'd have that many problems.
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Mar 3, 2016 21:07
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Speaking of GW1 air to air kills, a friendly reminder that that was the conflict that saw an A-10 air to air gun kill. Some poor loving Iraqi helicopter that got reduced to aluminum confetti. I distinctly remember 9 year old me thinking that was the coolest poo poo ever. 33 year old me still ranks it pretty loving up there.
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Mar 3, 2016 21:13
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