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Cool, so they did modify the frame. They'll still be subject to most weapons' lower g-limit though.
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May 31, 2010 20:10
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What weapons have a G-limit lower than the aircraft's? Surely not the missiles, seeing as they're supposed to be able to out-turn another plane (The Sidewinder's safety doesn't even arm the warhead until after 5 seconds of 20G acceleration, and the AIM-9X has vectored thrust that makes it capable of something like 60G turns). That basically leaves bombs, though I don't really see a reason for them to have such a low G-limit. When it comes to weapons I'd be more concerned about the extra stress of a weapon hanging on at 9G causing damage to the wing than I would about the weapon itself.
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May 31, 2010 21:25
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ApathyGifted posted:What weapons have a G-limit lower than the aircraft's? Surely not the missiles, seeing as they're supposed to be able to out-turn another plane (The Sidewinder's safety doesn't even arm the warhead until after 5 seconds of 20G acceleration, and the AIM-9X has vectored thrust that makes it capable of something like 60G turns). That basically leaves bombs, though I don't really see a reason for them to have such a low G-limit. When it comes to weapons I'd be more concerned about the extra stress of a weapon hanging on at 9G causing damage to the wing than I would about the weapon itself. While the weapons themselves can take a tremendous amount of G-loading during their short flight, there are a number of other limitations on how much g-force can be applied to a weapon mounted on an aircraft. First, there might be a limit based on the strength of the attachment points on the weapon itself. Second, the pylon itself might be limited on how much force it can withstand under a given set of conditions. Also, the separation system has limitations as to how much g-force it can take while still being able to guarantee that the weapon will separate from the aircraft cleanly.
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May 31, 2010 21:47
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Yeah, that's a much better explanation than my half-assed attempts. Although certain types of fuzes do have a limit, I don't have a specific example. I think they're all air-to-ground munitions.
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May 31, 2010 22:05
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ApathyGifted posted:What weapons have a G-limit lower than the aircraft's? Not exactly late-breaking news, but I've read that feed mechanism on the 20mm Colts on the F-8 Crusader liked to jam under high G maneuvers.
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Jun 1, 2010 05:20
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Random images I've collected over the years. Some sort of experimental wing:  I took this picture during Redflag 1990.  B-52 showing the Navy what's what:  Air Tractor showing power lines what's what:  A-10 Thunderbolt II (Warthog) looking all warthoggy:  Pratt & Whitney J-58 (SR-71 power plant) on the test cell:  Another Test Cell image (unsure of make & model engine):  Another Jet Train:  Misuse of a radial engine:  GE90-115B on Boeing 777:  Result of a midair between glider and Hawker 800XP (no deaths!):  Hawker 800XP with minor missile damage:  What happens if you don't follow your checklist (accidental nose gear retraction): B-52 acting as engine test bed: A-1 Skyraider delivering modern plumbing to the North Vietnamese: Where I work: 
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Jun 1, 2010 18:37
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LOO posted:B-52 acting as engine test bed: This is what I've wondered. I know a B-52 served as an engine test bed for the 747-100's engines, but I've heard is nearly impossible to re-work the B-52 fleet to move from 8 to 4 engines. Are the plumbing/electrical/mechanical connections so complex that the Air Force can't swap out the current layout for four engines with better economy and higher thrust?
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Jun 1, 2010 18:43
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Minto Took posted:This is what I've wondered. I know a B-52 served as an engine test bed for the 747-100's engines, but I've heard is nearly impossible to re-work the B-52 fleet to move from 8 to 4 engines. Are the plumbing/electrical/mechanical connections so complex that the Air Force can't swap out the current layout for four engines with better economy and higher thrust? If they can replace #4 & #5 with one big engine (as pictured), they can replace them all. My understanding is that wasn't economically advantageous to do so. Probably because they spent the money on B-1 Lancers, and B-2 Spirits.
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Jun 1, 2010 19:16
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Do you work for Netjets, Loo?
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Jun 1, 2010 19:31
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VOR LOC posted:Do you work for Netjets, Loo? No, but the FBO I work for maintains most of their Hawker fleet.
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Jun 1, 2010 19:33
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Saab geek checking in. Stole some pictures from airliners.net. Draken  Click here for the full 1024x696 image.  Click here for the full 1024x695 image.  Click here for the full 1200x812 image. Viggen  Click here for the full 1024x739 image.  Click here for the full 1024x695 image.  Click here for the full 1024x695 image. Some Gripen for good measure. Not quite as much of a looker as the Draken and Viggen, though.  Click here for the full 1200x812 image.  Click here for the full 1024x695 image.  Click here for the full 1024x695 image. They make civilian aircraft too, but really, who cares about those!
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Jun 1, 2010 19:51
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When flying in formation the leader really is the leader. Dude doesn't look at anything else https://www.youtube.com/watch?v=M725Qw6_UIM
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Jun 1, 2010 21:19
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slothrop posted:After reading The Right Stuff earlier this year I feel that sometimes we forget about the totally rockin' dudes who flew the amazing planes we have such a hard on for (not saying I don't) Going back a page, but my personal favorite is Ted Williams. Probably the best hitter to play baseball, he was the last batter with an over .400 batting average. In 1941, he had a .406 average over the entire season. The next year he was drafted as a Marine pilot. During the war he broke all gunnery records, and instructed on Corsairs, he was in Pearl Harbor awaiting deployment when the war ended. After the war he returned to the Red Sox, only to be called back in 1952 for Korea, flying the F9F....as John Glenn's wingman. Of course there's always Smokey Yunick and his time in bombers, but that's a given for AI I suppose.
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Jun 1, 2010 21:53
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Nuclear Tourist posted:Saab geek checking in. Stole some pictures from airliners.net. There were a bunch of Tunnan shots on http://planeshots.tumblr.com/ yesterday. I believe it is the only Saab to have been used in combat.
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Jun 1, 2010 22:57
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LOO posted:If they can replace #4 & #5 with one big engine (as pictured), they can replace them all. My understanding is that wasn't economically advantageous to do so. Probably because they spent the money on B-1 Lancers, and B-2 Spirits. It's all a money issue. The E-3 AWACS and E-8 JSTARS use the same engines and will continue to do so for the same reason. The AF doesn't have the cash for new engines, especially when there are hundreds (maybe thousands) of spares sitting around. The same engine used to be on the KC-135s (all re-engined with CFM-56 or retired) and C-141 (retired), plus a handful of other low-production aircraft. Edit: VVV 
Godholio fucked around with this message at 23:46 on Jun 1, 2010 |
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Jun 1, 2010 23:00
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Minto Took posted:This is what I've wondered. I know a B-52 served as an engine test bed for the 747-100's engines, but I've heard is nearly impossible to re-work the B-52 fleet to move from 8 to 4 engines. Are the plumbing/electrical/mechanical connections so complex that the Air Force can't swap out the current layout for four engines with better economy and higher thrust? They could do it, but there's so many spare TF33's lying around that it's still just cheaper to use them instead.
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Jun 1, 2010 23:00
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Slo-Tek posted:There were a bunch of Tunnan shots on http://planeshots.tumblr.com/ yesterday. Can't believe I forgot about Tunnan  That's what I get for posting half asleep.
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Jun 1, 2010 23:43
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slidebite posted:Lots of pics No WWII warbird photos?!  I was just there this past Saturday and I agree, I could easily spend an entire day there.
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Jun 2, 2010 00:35
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Hey guys i heard saab tried making cars at one point, c/d?
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Jun 2, 2010 07:10
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Fucknag posted:Hey guys i heard saab tried making cars at one point, c/d? 
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Jun 2, 2010 09:36
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Nuclear Tourist posted:Saab Goodness Yay Saabs! I like 'em and I'm not even Swedish. I guess it's because in my mind that's what we should have been putting out, planes that are fairly inexpensive, rugged, and suited for a northern climate. Also I don't know how they did it but the Draken manages to combine the plainest fuselage with the sexiest planform imaginable. Seriously from the side it's basically a tube with a rudder and then get any sort of angle so that the wings are visible and suddenly it looks like something out of a goddamn top-down shooter.
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Jun 2, 2010 09:46
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Minto Took posted:This is what I've wondered. I know a B-52 served as an engine test bed for the 747-100's engines, but I've heard is nearly impossible to re-work the B-52 fleet to move from 8 to 4 engines. Are the plumbing/electrical/mechanical connections so complex that the Air Force can't swap out the current layout for four engines with better economy and higher thrust? Re-engining the B-52 fleet is actually being considered, but it seems to be dead at the moment. Boeing proposed converting the B-52 fleet to use Rolls-Royce RB211's (which power the 747, 757 and 767), but the GAO claimed that the Boeing cost study was inaccurate and the program would be too costly, which stopped the idea in the early 2000's. In 2003, a Defense Sciences Board claimed that the GAO report was flawed, and the original Boeing proposal was correct, resulting in the Defense Sciences Board urging the Pentagon to re-engine the B-52 fleet. That recommendation was made in 2004, so it does appear that the re-engining program is dead for now, but since the B-52 is supposed to be around for another 40 years or so, I wouldn't be surprised if the engines aren't replaced eventually.
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Jun 2, 2010 15:09
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They'll probably consider it again when the pile of spare TF33s starts to run down.
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Jun 2, 2010 15:18
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blambert posted:When flying in formation the leader really is the leader. Dude doesn't look at anything else Incredible. I just sat agape while watching that. 
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Jun 2, 2010 17:50
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They should use four of the GE90 777 engines. That thing would be so beastly.
OptimusMatrix fucked around with this message at 18:02 on Jun 2, 2010 |
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Jun 2, 2010 17:58
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OptimusMatrix posted:They should use four of the GE90 777 engines. That thing would be so beastly. and so would its radar signature
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Jun 2, 2010 18:11
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kill me now posted:and so would its radar signature Yes it's as if it was almost non existent as it is now.
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Jun 2, 2010 18:15
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OptimusMatrix posted:They should use four of the GE90 777 engines. That thing would be so beastly. I can't imagine how governed they'd have to be. Four of those at full throttle could rip up the wings.
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Jun 2, 2010 19:46
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Minto Took posted:I can't imagine how governed they'd have to be. Four of those at full throttle could rip up the wings. Don't you mean rip the wings clean off, like the B-47? Gated throttles so you don't overspeed the airframe?
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Jun 2, 2010 20:49
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MA-Horus posted:Don't you mean rip the wings clean off, like the B-47? Gated throttles so you don't overspeed the airframe? Either or, I guess. I forgot the numbers but the net thrust of two GE90s is the same if not more than eight TF33s. e: Never mind. Two GE90s are 77k lbf whereas eight TF33s are 136k lbf. e^2: Depends on the model. Two GE90s in the 773ER produce 230k lbf net thrust. e^3: I can't read tables. Full Collapse fucked around with this message at 21:23 on Jun 2, 2010 |
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Jun 2, 2010 20:51
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According to Wikipedia, the TF-33s in the B-52 put out about 17,000lbs each, for a total of 136,000lbs. A single GE90-115b puts out 115,000lbs of thrust. Mounting 4 of them on a B-52 would count as gross overkill. Even just two of them is going to be a bit much, although there are lower rated variants that may be more appropriate. A pair of the lowest end models (GE90-76b) would still give you about 12% more thrust than the old 8xTF-33 configuration.
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Jun 2, 2010 21:01
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Beaten. Goddamn phone calls /\/\/\ And yes I agree I said 4 but 2 of the lower to midrange engines would be plenty. Minto Took posted:Either or, I guess. I forgot the numbers but the net thrust of two GE90s is the same if not more than eight TF33s. Yes but the bottom of the line GE90 produces 77k lbf whereas the highest model creates 115k lbf. So wouldn't it be more fuel efficient and mechanically effiencient to only have 2 engines instead of 8?
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Jun 2, 2010 21:14
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OptimusMatrix posted:Beaten. Goddamn phone calls /\/\/\ Air Force likes to have four engines in their bombers.
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Jun 2, 2010 21:17
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I'm fairly certain that due to the B-52's drooping wings that the GE90 wouldn't even fit under them anyway. The GE90 is almost bigger around than the fuselage of a 737, after all. Even it it did manage to fit under there you'd be making GBS threads yourself over FOD. Hell, here's a picture of a GE90 fitted to a 747 for testing. That one engine was able to keep the entire 747 flying, by itself. 
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Jun 2, 2010 21:17
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Well, if you install just two of the -115 models, you could have one engine blown completely off and still have more than enough thrust to keep flying. Shoot, you could take off with one engine with a most of a load of fuel and bombs. That single GE90 is producing 85% of the thrust of all 8 TF-33s. Actually fitting the engines under the B-52 is an exercise left to the reader.
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Jun 2, 2010 21:21
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jandrese posted:Well, if you install just two of the -115 models, you could have one engine blown completely off and still have more than enough thrust to keep flying. Shoot, you could take off with one engine with a most of a load of fuel and bombs. That single GE90 is producing 85% of the thrust of all 8 TF-33s. 2 huge targets under wings aren't very good for survivability when someone is actively gunning for you.
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Jun 2, 2010 21:44
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Well I was able to find the height of the b52's fuselage is 17'6" and I found that the GE90-115b has a diameter of 11'3" so it would fit barely.
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Jun 2, 2010 21:45
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Muffinpox posted:2 huge targets under wings aren't very good for survivability when someone is actively gunning for you. Line the wings and fuselage with hundreds of go-kart pulsejets
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Jun 2, 2010 21:54
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Muffinpox posted:2 huge targets under wings aren't very good for survivability when someone is actively gunning for you. I really don't think it's going to make that much of a difference in terms of survivability.
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Jun 2, 2010 21:56
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What if you mounted 8 of them in 4 pods, hmm?
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Jun 2, 2010 22:19
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