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Ola posted:A funny one was a C-130 banked at 45 degrees, seriously low level and the right seater was eating an apple. wanna see this
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Jun 26, 2010 14:17
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Ola posted:Hahaha that's amazing. If you search for "mach loop" on airliners.net you will be treated to a huge amount of action shots like these, a few of them shows the crew waving to the photographers (who are there almost all the time). "Machynlleth Loop" gets the most results (and holy cow, these are fantastic)
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Jun 26, 2010 17:08
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Lilbeefer posted:wanna see this http://www.airliners.net/photo/UK---Air/Lockheed-Martin-C-130J/1340854/L/&sid=22a2cedec5cc54b620fab9a7cd1c7f80
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Jun 26, 2010 17:23
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ehnus posted:http://www.airliners.net/photo/UK---Air/Lockheed-Martin-C-130J/1340854/L/&sid=22a2cedec5cc54b620fab9a7cd1c7f80 Wow, I never realized until that photo (and others from the same valley) how dirty/scratched airplanes get. Quite a few with panels replaced and not repainted to match, too, like a car with a junkyard fender after a minor wreck. Mudhen missing a lot of paint: http://www.airliners.net/photo/USA---Air/Boeing-F-15E-Strike/1678572/L/&sid=6c2f8c9c44c95c53d264dc0bec4139a8 Also F-15s are really disturbingly wrinkly in the right light. http://www.airliners.net/photo/USA---Air/McDonnell-Douglas-F-15E/1606731/L/&sid=6c2f8c9c44c95c53d264dc0bec4139a8
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Jun 27, 2010 04:57
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Bad Angus! Bad!
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that looks like it may be water vapor that forms on the leading edges of wings sometimes.
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Jun 27, 2010 06:14
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Alpine Mustache posted:that looks like it may be water vapor that forms on the leading edges of wings sometimes. And this one, while not lumpy, is so  I had to rehost it and post inline. I know that one is about twice the size of the other, but seeing them together just breaks my brain. And the P-51 is actually smaller than it looks, what with the perspective and all. P-51 max takeoff weight: 12,100 lb F-15E external fuel/ordnance capacity: 24,250 lb Progress!
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Jun 27, 2010 07:53
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The airshow here in '03 had a heritage flight like that, and it was hilarious to see the Mustang screaming the revs while the Eagle toggled flaps and idled his engines.
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Jun 27, 2010 11:45
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Delivery McGee posted:I know that one is about twice the size of the other, but seeing them together just breaks my brain. And the P-51 is actually smaller than it looks, what with the perspective and all. B-17G length: 74' F-15E length: 64' B-17G max takeoff weight: 65,500 lb (29,700 kg) F-15E max takeoff weight: 81,000 lb (36,700kg) B-17G max bomb load: 8,000 lb F-15E max bomb load: 24,250 lb
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Jun 27, 2010 14:46
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Ok now that's incredible.
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Jun 27, 2010 15:06
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grover posted:Speaking of modern-WWII comparisons: This broke my brain. I used to make models of bombers when I was a kid and had four or five B-17 kits. I mean, there were rooms in there! 
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Jun 27, 2010 17:08
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Not technically aeronautical, but along similar lines: Indiana class Battleship (1895-1919): 351 ft long Arleigh-Burke class Destroyer (1991-present): 509 ft long They're virtually the same tonnage, too.  Relevant (almost), because Arleigh-Burke class destroyers are powered by 4 General Electric LM2500-30 gas turbines- the same engine used in the Boeing 747, Boeing 767, Airbus A300, Airbus A330 and others. I saw one after it'd been pulled from a Perry class frigate and it was amazing just how small it is. I mean, when you compare it to the massive triple expansion steam engine of the Indiana, or even more recent steam turbines, it's astounding how small the engine itself really is. And only half this is the actual turbine, the rest is intake and exhaust ducting:  grover fucked around with this message at 17:56 on Jun 27, 2010 |
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Jun 27, 2010 17:44
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grover posted:
I was a gas turbine mechanic, and I served on a 'Burke. Where the dude has his hand is about where the outlet of the Hp turbine is. Just behind that is the turbine rear frame and then you have the 6 stage LP turbine, which is coupled to the shaft via a high speed flexible coupling and a really wild clutch setup that's stuffed inside the main reduction gear. The first set of compressor blades are almost visible. Actually, it would be the first set of inlet guide vanes....but you get the point. The MRG on any naval vessel is is frigging huge. They pretty much have to be to handle the 1.6 MILLION ft/lbs of torque that the shaft is limited to. Without seeing one, or the inside of one it's hard to understand how precise and HUGE the gears are inside. Seriously, during annual inspections three of us would crawl inside that fucker. The whoosh of two of those bad boys spooling up, going from idle to flank speed made my dick move a little bit.
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Jun 28, 2010 03:50
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grover posted:Sweet tittyfucking Jesus, our  destroyers are JET loving PROPELLED? Somehow I just assumed all modern ships were powered by giant diesels, this changes everything. What I wouldn't give for a schematic of that drive train...   It's bullshit, I know, but I'm trying to bridge the gap here.
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Jun 28, 2010 06:47
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Sterndotstern posted:
Where's this from? Or is it just some random piece of art?
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Jun 28, 2010 09:49
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ehnus posted:http://www.airliners.net/photo/UK---Air/Lockheed-Martin-C-130J/1340854/L/&sid=22a2cedec5cc54b620fab9a7cd1c7f80 Holy hell, I remembered it wrong. That's way beyond 45 degrees, but perhaps the photographer was at a higher altitude (!) as well, adding to the vertical bank effect.
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Jun 28, 2010 16:45
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There's some decent vids bottom right of this page showing all the photographers and the planes coming through: http://www.mjaviation.co.uk/Lowfly.htm
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Jun 28, 2010 17:07
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Great link, lots of aircraft geek-fuel there!
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Jun 28, 2010 17:49
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Sterndotstern posted:Sweet tittyfucking Jesus, our Well, many are nuclear powered. Which is why a giant aircraft carrier can outrun its support fleet and still go years between fuel stops. Also submarines, since burning jet fuel is neither quiet nor safe in an enclosed space.
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Jun 28, 2010 18:02
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Nuclear Tourist posted:Where's this from? Or is it just some random piece of art? Yeah, some Fernando Feria guy I guess, but I liked the subject matter and aesthetic quite a bit. Tracked this down as the original: http://airaf.cgsociety.org/gallery/333906/
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Jun 28, 2010 19:21
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Eh, quote != edit.ApathyGifted posted:Well, many are nuclear powered. Which is why a giant aircraft carrier can outrun its support fleet and still go years between fuel stops. Well of course they're also nuclear powered, but I guess I just found the gas turbine jet/ship crossover too interesting to resist posting about. On a completely different topic, a while ago I posted that air-burning, air-flying technology reached its logical conclusion in approximately 1965 and stated (somewhat controversially) that we're "done" with aircraft. I never got to ask the obvious follow-up question: Where is the next great unsolved problem for aerospace engineering? My only guess is a low-maintenance, high-reliability (human rated) spaceplane/shuttle application. With the looming retirement of the Space Shuttle and the advent of multiple private-sector commercial launching companies, how long will it be before I can book a couple hundred pounds of human payload onto a shuttle? Is the multi-stage solution (i.e. White Knight) desirable and viable in the long term? Is there an even more extreme (but viable) first stage looming? Dirigible spaceports, anyone?
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Jun 28, 2010 19:36
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IMHO, it's going to take massive technological breakthrough to make space travel affordable to the average person. You just need too much energy to get the mass into orbit, and that energy has to come from fuel, which costs money. About the best you can do is what Rutan and others are trying: use relatively cheap air breathing engines to get you as far as you can, then light off the rockets to finish off the last 90% of the journey (it does get the rockets out of the area where they are least efficient at least). What we really need is cheap and efficient antigravity. That's the key to getting into orbit at low cost. As long as you're burning chemical rockets, it's going to cost an arm and a leg to get there, and there is no way in hell any government in the world is going to approve of a nuclear rocket design. RTGs are hard enough to get into orbit.
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Jun 28, 2010 20:20
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jandrese posted:As long as you're burning chemical rockets, it's going to cost an arm and a leg to get there You can get quite a lot of energy density by electrolyzing water. Rocket-fuel kind of energy density. The space shuttle uses liquid hydrogen/liquid oxygen rocket motors that weigh ~7,000lbs for a 400,000lbs thrust output. Rocket fuel is green as gently caress when it's water.
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Jun 28, 2010 20:43
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Yep, if we could mine pure H2 and pure O2 to stick in the rockets, we could put everybody into orbit. Unfortunately, nobody has made a Hydrogen mine yet, so you have to create it yourself, either from water or from hydrocarbon based sources like natural gas. O2 you pretty much have to get from the air. The Hydrocarbon based approach isn't green; and thanks to the pesky laws of thermodynamics you need to put even more energy into creating the H2 and O2 than you get out of it if you're cracking water. All of that energy costs money, lots of money for the quantities involved.
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Jun 28, 2010 20:50
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Sterndotstern posted:I never got to ask the obvious follow-up question: Where is the next great unsolved problem for aerospace engineering? 
grover fucked around with this message at 03:32 on Jun 29, 2010 |
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Jun 29, 2010 03:28
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I wouldn't say scramjets are "unsolved" just.. "seriously early in development" Heck the wright brothers engine used flame tubes for ignition!
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Jun 29, 2010 05:00
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We just tested a working SCRamjet up to Mach 5 a few months ago. It wasn't even the fastest ever, just the longest flight so far (200 seconds). In 2007, DARPA and some Australians (DSTO) flew one to Mach 10. There was even a DARPA project (Blackswift) that was working on a hybrid turbine/SC/Ramjet design that would have been able to go from 0 to Mach bitchin' fast. But that got canceled because assholes don't know the value of building kickass poo poo.
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Jun 29, 2010 05:22
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ApathyGifted posted:There was even a DARPA project (Blackswift) that was working on a hybrid turbine/SC/Ramjet design that would have been able to go from 0 to Mach bitchin' fast. But that got canceled because assholes don't know the value of building kickass poo poo. But what's the operational advantage of burning air? \/\/ to rephrase, "why bother to burn air when it's really hard to do so and you want to go sub-orbital or orbital anyway?" Sterndotstern fucked around with this message at 09:20 on Jun 29, 2010 |
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Jun 29, 2010 07:35
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Sterndotstern posted:But what's the operational advantage of burning air? Not needing to carry oxidizer. It's the efficiency difference between a rocket and a jet.
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Jun 29, 2010 08:40
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ApathyGifted posted:But that got canceled because assholes don't know the value of building kickass poo poo. This could be applied to so, so many things.
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Jun 29, 2010 09:09
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Stuff...         Edit: Added a few shots. LOO fucked around with this message at 16:58 on Jun 29, 2010 |
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Jun 29, 2010 15:29
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jandrese posted:
Tell you what, if you can cook up even expensive and inefficient antigravity, the Swedish king has a medal for you.
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Jun 29, 2010 16:08
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LOO posted:Stuff... Best plane ever.
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Jun 29, 2010 16:10
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Sterndotstern posted:But what's the operational advantage of burning air? It's not hard to burn air, just hard to burn it while it's going supersonic. Rockets have the advantage of their "intake" velocity being zero, so any accelerating of exhaust gases is all thrust. But that's basically the only advantage rockets have over SCRamjets inside the atmosphere. Rockets have some huge disadvantages that SCRamjets don't, though: - A rocket's thrust has to provide both propulsion AND lift, until it's got enough velocity that the curvature of the earth and the sheer speed provide "lift." - A rocket needs double the "fuel", minimum, because it has to carry an oxidizer in a separate tank to burn the fuel. A SCRamjet aircraft can provide it's own lift, so that all thrust just goes to achieving orbital velocity. It doesn't need an oxidizer for at least the first 200,000 feet of altitude, during which it can theoretically achieve orbital velocity. Basically, a SCRamjet can get you into orbit cheaper than a rocket, most likely with a larger payload, and would be able to take off from a runway instead of needing specialized launch facilities. On top of all that, you can use it to get passengers from New York to Hong Kong something like 2 hours.
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Jun 29, 2010 17:19
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ApathyGifted posted:It doesn't need an oxidizer for at least the first 200,000 feet of altitude, during which it can theoretically achieve orbital velocity. Ah, so that's the reason for them: attaining orbital speeds while still in the atmosphere. LEO requires ~16,000 mi/hr or so, mach 25 and up. Does SCRamjet combustion get more efficient/stable/easier with increased mach numbers? So realistically the only application is a Single Stage to Orbit (SSTO) lifter. But once you leave the atmosphere, that air-burning engine and fuel just become parasitic mass, reducing payload. Seems to me there's just no getting away from a multi-stage approach to orbit, or at the very least, detachable external boosters (air burning or not).
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Jun 29, 2010 17:51
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Most solutions would seem to require a built-in rocket, yes. However, it would be along the lines of STS's OMS rockets, rather than the main engines and their attendant giant fuckoff fuel tank. Fairly small since they only need to be used for a short time, and within a single operating regime (vacuum). Basically, the SCRamjet would get you enough speed to reach apogee, then the rocket would be used for the final speed boost to raise perigee above the atmosphere. If something as big and obsolete as the shuttle can carry fuel for those maneuvers, a smaller, lighter spacecraft should have no trouble with it. That said, we could see a rocket-powered orbiter powered aloft by scramjet boosters that then seperate and
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Jun 29, 2010 20:28
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Sterndotstern posted:So realistically the only application is a Single Stage to Orbit (SSTO) lifter. But once you leave the atmosphere, that air-burning engine and fuel just become parasitic mass, reducing payload. It is extra weight, but scramjets (please stop capitalising the scr-, nobody in the industry does) are mechanically very simple and won't add much extra weight beyond what a rocket-powered SSTO vehicle would need for its propulsion. The advantage of not needing to carry oxidiser for the main propulsive event is a big one; it outweighs any concerns regarding the weight of the engines. Remember that for every pound you need to lift, you need burn even more fuel to lift it and the additional structural weight needed to carry that extra pound. This applies to fuel too; for every extra pound of fuel you carry, you need to carry an additonal amount just to lift the added fuel - it becomes clear that weight becomes a problem that feeds back on itself quite dramatically in and aerospace application. With a scramjet-powered orbiter, you would almost eliminate the need to carry oxidiser, which is a huge savings in terms of weight, volume and complexity. Getting back to what you asked earlier: Sterndotstern posted:My only guess is a low-maintenance, high-reliability (human rated) spaceplane/shuttle application. The scramjet is pretty much the most likely ticket to affordable, reliable transportation to orbit, especially if researchers can iron out the kinks with regard to burning conventional hydrocarbon fuels. MrChips fucked around with this message at 21:23 on Jun 29, 2010 |
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Jun 29, 2010 21:19
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MrChips posted:It is extra weight, but scramjets (please stop capitalising the scr-, nobody in the industry does) I am in the industry, and I'm the one capitalizing it.  But that's because it's an abbreviation and I'm a dick. Sterndotstern posted:So realistically the only application is a Single Stage to Orbit (SSTO) lifter. But once you leave the atmosphere, that air-burning engine and fuel just become parasitic mass, reducing payload. Seems to me there's just no getting away from a multi-stage approach to orbit, or at the very least, detachable external boosters (air burning or not). There's SST applications too. Staying in the atmosphere or reaching near-orbital velocities and skipping off the top for a while would drastically reduce flight times. And since the engines are simpler, it's entirely possible to make them profitable at an affordable price, unlike the Concorde. That's what the National Space Plane was supposed to become, but once again: people don't know the value of building kickass stuff. New York to Hong Kong faster than New York to Los Angeles today is pretty drat amazing.
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Jun 29, 2010 21:59
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ApathyGifted posted:I am in the industry, and I'm the one capitalizing it. I know it's an abbreviation. And if you can show me an abstract or a paper that refers to this engine as a "SCRamjet" instead of "scramjet", then I'll believe you.
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Jun 29, 2010 22:06
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MrChips posted:I know it's an abbreviation. And if you can show me an abstract or a paper that refers to this engine as a "SCRamjet" instead of "scramjet", then I'll believe you. MrChips posted:(please stop capitalising the scr-, nobody in the industry does) ApathyGifted posted:I am in the industry, and I'm the one capitalizing it. I never claimed anyone else did it. ApathyGifted fucked around with this message at 22:10 on Jun 29, 2010 |
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Jun 29, 2010 22:07
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ApathyGifted posted:- A rocket's thrust has to provide both propulsion AND lift, until it's got enough velocity that the curvature of the earth and the sheer speed provide "lift." Not really completely true about "rockets" as a engine though, The current rocket designs tend to have that issue (ie a tube with the engine at the bottom), but you can design a "rocket" with wings that takes off horozontally and uses the wings for lift, it will just take longer to escape than taking off vertically. The ME163 had wings for lift and a rocket for thrust, and worked pretty well for its design envelope (ie not trying to get to escape velocity etc). Also the RATO and JATO units are rockets and generate no lift on their own, they just add lots of thrust to get the plane off the deck fast.
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Jun 29, 2010 22:56
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