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Wingnut Ninja posted:A while back I was bored during a flight, bullshitting with the pilots, and looked up the glide performance of the E-2 in the manual. Turns out that from 28k feet, with one prop feathered and one windmilling (required to provide emergency hydraulic power for the flight controls), it can allegedly glide 47 miles, for a glide ratio of about 8.8. That's assuming some kind of catastrophe that kills both engines simultaneously, like all our fuel spontaneously transmuting into Kool-Aid. Wingnut Ninja posted:Speaking of shutting down engines, Thursday was interesting: Congrats an almost-but-not-really putting that into practice! 
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Oct 21, 2014 01:49
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CommieGIR posted:Um.....what? How is it a failure? EADS is still selling each unit at a loss. 2015 is supposed to be the break-even point. Don't think it's a failure quite yet.
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Oct 21, 2014 01:51
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dubzee posted:EADS is still selling each unit at a loss. 2015 is supposed to be the break-even point. That's what I thought. And even then, Airbus makes money on replacement parts and depot level maintenance in many places. Its can hardly be considered a failure yet.
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Oct 21, 2014 01:52
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Cat Mattress posted:Isn't the A380 already above the limit for many airports? And that being one of the reasons why it's not selling well? I don't think airport infrastructure has been a huge issue for A380 sales, most large airports have at least one gate that can handle it and prospective A380 service has a way of spurring renovations to accommodate one. I think the real issue might be airlines reluctant to put that many seats on an airplane - no one wants to be the one to dump huge capacity into a route and lose their shirts to the competitor that only takes off if their plane is completely full.
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Oct 21, 2014 01:54
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CommieGIR posted:Um.....what? How is it a failure? To avoid this becoming a multi-thousand word effortpost, the A380 is a commercial failure for a number of reasons. Put simply, the market that Airbus targeted with the A380 was grossly overestimated, and it shrunk faster than anyone could have expected as the airlines moved away from larger aircraft as a whole as aircraft performance and efficiency improved. In the last 15-20 years, the rise of low-cost airlines in many domestic markets, coupled with the opening of competition on international routes, has forced airlines to compete as much on frequency as they do on cost. Instead of flying a single flight with 600 seats per day, they now fly two flights of 300 seats per day, or five of 120 per day. Additionally, airlines had been historically hamstrung by aircraft performance - it used to be that on many routes, a Boeing 747 was the only aircraft capable of flying that route and turning a profit, on account of its size, range and (relative) efficiency. With the rise of widebody twins in the 1980s, first with the A310 and the 767, these aircraft proved that a twin-engine aircraft could deliver favourable performance and safety, all while opening up routes to markets previously unserved because a 747 was simply too big. In the 1990s and 2000s, the A330 and 777 further refined the concept laid out in the 1980s. In both aircraft, we had a viable replacement for a 747 on many of the routes the world's airlines flew (especially in so-called "C-market" 777s, the -300ER and -200LR), all while being cheaper to buy, cheaper to maintain and cheaper to land (most landing fees are based on max gross weight; the 777 and A330 enjoy a hefty savings over a 747 in this area). Also like the first generation of widebody twins, these aircraft opened up hundreds of routes that were previously unreachable, either economically or performance-wise - routes that would previously been served by a domestic flight connecting to a hub, from which a 747 (or 747s) would have operated. The newest generation of twins, the A350 and the 787, along with the future 777-8 and -9, are so efficient that they once again increase the number of routes that can be flown economically, which will further cut into the traditional "hub-and-spoke" system that the A380 was tailored to. That's not to say that the A380 is without a place in the world; it does have a performance and economy advantage over basically any airliner in service today, and it is useful in places where there are things like landing slot restrictions (like many European and Asian airports), but that performance and capability comes at a cost that is simply too high for most airlines to justify. If you have unlimited money (*cough*Emirates*cough*), then that doesn't really matter - which explains why Emirates flies very nearly half the total fleet of A380s. It also explains why their CEO, Sir Tim Clark, has basically acknowledged that most of their A380 fleet will probably be scrapped or parked in the desert after they're done with them - there really aren't any other airlines that seem interested in flying the A380. It isn't like Boeing is immune to this trend either; the latest version of the 747, the -8, is selling in very small numbers, and has only a tiny handful of orders for the passenger variant. Another reason why the A380 is a commercial failure is because of the enormous cost overruns and delays Airbus experienced developing the aircraft. Even today, almost ten years after the first flight, the A380 production process remains a horrible mess (in contrast to the slick setup that Airbus' other models enjoy), with aircraft taking too long to assemble and requiring too much rework before they are accepted into service. As a result, the so-called "break-even point", the number of aircraft needed to be sold before the project turns a profit (assuming that proceeds from the sale of the aircraft prior to this go entirely to paying for development cost) absolutely skyrocketed - they still haven't broken even on the program, and they aren't forecast to until late next year...assuming no orders are cancelled in the meantime. That is a good thing by itself, but the problem is that there have been few, if any, new orders to keep the line open in the future; currently, Airbus has a backlog of A380 orders that will keep the line open for five years, but so far this year, they've only secured 14 net orders...not a good sign for the long-term viability of the project. Well I guess this did turn into a bit of an effortpost, but there you have it - the market evolved away from the A380, and Airbus has struggled to deliver A380s on time and on budget. MrChips fucked around with this message at 02:15 on Oct 21, 2014 |
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Oct 21, 2014 02:13
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That's a solid post, thank you 
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Oct 21, 2014 02:32
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MrChips posted:It isn't like Boeing is immune to this trend either; the latest version of the 747, the -8, is selling in very small numbers, and has only a tiny handful of orders for the passenger variant. Last I heard (but it's been a while since I checked) only Lufthansa had bought the passenger-version 748, with limited sales of the freighter variant.
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Oct 21, 2014 05:10
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It also doesn't help that there's not a dedicated freighter version of the A380, since delays in the delivery process caused customers of the freight version to cancel their orders. With a relatively large number of 747-400's available that can be converted to freighters relatively cheaply, and Boeing holding something like 90% of the large freighter market, it's kind of hard to see an established freight company deciding to suddenly buy an A380, when the 747-800F has a similar payload and wouldn't require a completely different type rating for the pilots.
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Oct 21, 2014 05:28
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simplefish posted:Last I heard (but it's been a while since I checked) only Lufthansa had bought the passenger-version 748, with limited sales of the freighter variant. Also a few to Air China, Korean Air, Transaero (probably,) and middle eastern potentates. Really the 747-8's problem is the 777-300ER, which is only tiny fractions behind it in capacity, and more efficient. azflyboy posted:It also doesn't help that there's not a dedicated freighter version of the A380, since delays in the delivery process caused customers of the freight version to cancel their orders. Cargo converted 747-400s have actually fallen by the wayside recently, the air cargo market is just okay and dedicated -400Fs and 777Fs can carry the load.
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Oct 21, 2014 05:31
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simplefish posted:Last I heard (but it's been a while since I checked) only Lufthansa had bought the passenger-version 748, with limited sales of the freighter variant. Actually the 747-8 freighter is the better seller. It's easier just to link to the chart: http://en.wikipedia.org/wiki/Boeing_747-8#Orders_and_deliveries Once Emirates has all 140 of their A380s delivered, if they had them all in the air at once they could be flying about 70,000 people at once. That's kind of wild. Are they actually using all those planes?
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Oct 21, 2014 05:31
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simplefish posted:Last I heard (but it's been a while since I checked) only Lufthansa had bought the passenger-version 748, with limited sales of the freighter variant. Boeing has sold a few -8Is to Korean Airlines, Air China, Transaero and Arik Air. Along with the eight or nine VIP 747-8s ordered, that's all they've sold of the passenger version. The -8F is selling a bit better, though, but it's sales are hurt by the fuckload of 747-400 freighter conversions (and soon-to-be-converted 747-400s) out there.
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Oct 21, 2014 05:33
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Most converted freighter 747-400s are parked in the desert right now. Apparently dedicated freighters in general are suffering from the high belly cargo capacities offered by passenger 777-300ERs and A380s.
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Oct 21, 2014 05:37
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Good point - the 777 and the A330 have huge cargo capacities (EDIT: the A380, not so much, actually), and they are eating up a ton  of the cargo market. Last I checked the split of ton-miles between dedicated cargo aircraft and belly cargo is almost 50:50, and the split will soon tilt in favour of belly cargo, with the A350 and 787 coming online in large numbers very soon.On that note, I heard from a friend who works in load control at Air Canada that they recently hauled 45 tons of cargo in the belly of a 777-300ER on one Toronto-London flight - that's like 50% of the capacity of one of FedEx's ubiquitous MD-11 freighters. MrChips fucked around with this message at 05:51 on Oct 21, 2014 |
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Oct 21, 2014 05:47
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The A380 isn't really a failure. Yes they sell at a loss, they're poo poo aircraft to operate/maintain and their break-even development point is more than double the current sales. The general consensus from my friends in Airbus/Boeing seems to be that the point of the A380 program wasn't to sell A380's, it was to stop Boeing overcharging on 747's to subsidize the 737/777 line and kill the A320/A330, which is where the real money is. Consider if the A320 and A330 lines weren't selling because they were more expensive than their subsidized Boeing counterparts (look at their respective sales figures up until the early 2000's), and the A380 didn't exist; on a scale of screwed->totally screwed, how hosed would Airbus be? The A380 program has actually achieved it's primary goal of stopping the legs being kicked out from under the A320/A330 by the 747. It just hasn't achieved its secondary goal of making money. And it might never achieve it. Ironically, I think the 748 is now doing to the A380 what the A380 did to the 744. No-one really minds if they don't make a net profit, although it'd be nice, it's just keeping the other guys honest in the far more valuable market. Captain Postal fucked around with this message at 06:55 on Oct 21, 2014 |
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Oct 21, 2014 06:53
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You guys are forgetting to factor in the cool factor of a double decker airliner.
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Oct 21, 2014 14:50
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Question: What  
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Oct 21, 2014 15:13
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Nebakenezzer posted:Question: What quote:Space shuttle Discovery is featured in this image photographed by an Expedition 26 crew member as the shuttle approaches the International Space Station during STS-133 rendezvous and docking operations. Docking occurred at 2:14 p.m. (EST) on Feb. 26, 2011. ISS026-E-037208 (26 Feb. 2011) #nasa #sts133 #Discovery #space http://instagram.com/p/JQbmP/ Surely they have a Flickr account for this instead of getting awful compressed pictures on Instagram. fake edit: yes they do A Handed Missus fucked around with this message at 15:50 on Oct 21, 2014 |
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Oct 21, 2014 15:47
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Air cargo is still off from the global peak, so the utility of any very large cargo aircraft is diminished compared to when the 748F and the A380F were on the drawing boards.
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Oct 21, 2014 15:58
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It seems like there should have been a better way:
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Oct 21, 2014 16:13
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Madurai posted:It seems like there should have been a better way: I wonder what the alpha of that F-8 is.
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Oct 21, 2014 16:21
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Nebakenezzer posted:Question: What What's the question? The cloud backdrop confusing you?
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Oct 21, 2014 20:00
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Nebakenezzer posted:Question: What I couldn't find the picture I wanted, so here's this one:  In the picture I wanted the shuttle looks really close to Earth. The guy who took the photo explained later that he just had a really really long telephoto and was zoomed in all the way. Like, you can make out ground stuff and all.
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Oct 21, 2014 20:39
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Well here's a video I never expected to see. Light aircraft requests to land at O'Hare for no real reason other than novelty... and Center acommodates. https://www.youtube.com/watch?v=KKvWn317tpU "..would like to do a full stop taxi-back at O'Hare." "Uhhh, you wanna do this at O'Hare? Alright, what type of aircraft?" "Cessna 172.  "E: didn't mean to time-stamp it, watch the whole thing. Fender Anarchist fucked around with this message at 20:53 on Oct 21, 2014 |
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Oct 21, 2014 20:43
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Fucknag posted:Well here's a video I never expected to see. Light aircraft requests to land at O'Hare for no real reason other than novelty... and Center acommodates. Wouldn't that be like 300 bucks in landing fees?
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Oct 21, 2014 20:49
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That is just completely awesome on so many levels. I would pay easily twice that in landing fees just to experience it. Loved the "Don't overshoot" warning.
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Oct 21, 2014 20:56
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I've seen Cessnas come in to MCO (Orlando International) fairly often, but O'Hare is just a whole different level. Now I wanna see them do the same thing at ATL and LAX for the hat trick. 
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Oct 21, 2014 21:01
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Fucknag posted:I've seen Cessnas come in to MCO (Orlando International) fairly often, but O'Hare is just a whole different level. Wish there was radio from the 747 in front of them. Everyone must have been pissing their pants laughing. Loved the "we got quite a few planes still" I lived under the main approach for a year and birds are comming in at least every 10 to 15 min. All day long.
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Oct 21, 2014 21:25
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Does a single-engine jet fighter roll noticeably quicker in one direction?
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Oct 21, 2014 21:35
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david_a posted:Does a single-engine jet fighter roll noticeably quicker in one direction? Nope. Jet engines don't exert any noticable torque on their airframes. The exhaust gases put torque on the turbines, yes, but that spins freely on bearings; all exhaust pressure on the engine housing is directly outward. In piston-engined planes, not only do you get the torque from the engine, but also the reaction torque from the propeller slipstream. As the propeller spins, it imparts a torque on the air, which pushes back (thank you Mr. Newton); that torque feeds back through the geartrain and adds to the engine's internal reaction torque, which is why it's such an issue on high-powered prop fighters. Dunno if that applies to turboprop engines, I imagine so since a lot of newer transports with them have counter-rotating props.
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Oct 21, 2014 21:44
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I asked a friend who's flown in Chicago and he says Center probably assumed this guy was a student once he said "Cessna 172" and decided to be nice; only the reason that it was late at night let him get away with it. During the day I'm sure they'd tell him to get the hell out, with good reason. but still haha, drat. Asking O'hare to let you land a 172 at all is hilarious.
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Oct 21, 2014 21:49
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Fucknag posted:Nope. Jet engines don't exert any noticable torque on their airframes. The exhaust gases put torque on the turbines, yes, but that spins freely on bearings; all exhaust pressure on the engine housing is directly outward. Can you explain (in slightly simpler terms, I'm not completely ignorant of physics but I'm not very literate either) how a P-51 (which I think is p much the strongest-engined single prop plane?) doesn't have to trim heavily to avoid rolling? I mean it'd probably be a non-issue if it had slightly asymmetric wings but I don't think it does
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Oct 21, 2014 21:56
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Inacio posted:Can you explain (in slightly simpler terms, I'm not completely ignorant of physics but I'm not very literate either) how a P-51 (which I think is p much the strongest-engined single prop plane?) doesn't have to trim heavily to avoid rolling? Its called p-factor and powerful props will have settings some rudder trim indicated in their pre take off checklist for this reason. No idea what the real P-51 is but the spergs that made DCS P-51 call for 5 degrees right trim and I would assume thats from real procedures. In a multi engine aircraft with both engines turning the same direction (as is typical), the one turning down into the wing cause more yawing than the other. This is termed the "critical engine" and sets the minimums for single engine operation on those aircraft. hobbesmaster fucked around with this message at 22:11 on Oct 21, 2014 |
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Oct 21, 2014 22:06
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Roll rate being affected by torque (which the original question was about) is definitely a thing. The Zero, for example, is pretty famous for rolling right a fair bit slower than left, albeit faster than early-war American planes in both directions; it could still out-turn them until we started getting planes like the Hellcat and Corsair into service. Torque is also a separate thing from p-factor; think of a dragster revving in neutral, the engine (or the whole car if the mounts are stiff enough) will twist to one side as throttle is applied, just from the load of spinning the decoupled crankshaft up. Now add the extra load of the drag that's acting to slow a propeller down, and you can see how it adds up. That said, the Zero is also notoriously light compared to the heavily-armored American planes; that extra mass helps a lot to dampen the force. It's still something to be accounted for, but it's also accounted for in the design phase, so there will be standard trim settings to compensate for it.
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Oct 21, 2014 22:22
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Inacio posted:Can you explain (in slightly simpler terms, I'm not completely ignorant of physics but I'm not very literate either) how a P-51 (which I think is p much the strongest-engined single prop plane?) doesn't have to trim heavily to avoid rolling? Question been answered, but just wanted to have a chuckle at you thinking the P-51 had the highest horsepower engine of a single prop fighter. Heck the P-47 had twice the horsepower, and a lot of the German fighters had horsepower around what the P-51 had.
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Oct 21, 2014 22:24
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ElBrak posted:Question been answered, but just wanted to have a chuckle at you thinking the P-51 had the highest horsepower engine of a single prop fighter. Heck the P-47 had twice the horsepower, and a lot of the German fighters had horsepower around what the P-51 had. Clearly he's referring to race P-51s. :P
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Oct 21, 2014 22:26
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hobbesmaster posted:In a multi engine aircraft with both engines turning the same direction (as is typical), the one turning down into the wing cause more yawing than the other. I've heard that a Sopwith Camel (where the actual engine rotates) could turn 270 degrees right faster than it could do 90 degrees left.
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Oct 21, 2014 22:28
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High performance = high hp is a reasonable mistake to make if you aren't familiar with the ins and outs of engines. If I had to guess, I'd say the A-1 Skyraider probably had the most hp for a single-engine prop production plane. david_a posted:Whoa. I always assumed planes with two engines had them spin in different directions. Although I guess that would make them different engines, huh? Depends on the engine. For example the Allison V-1710 in the P-38 was built such that you could basically swap a part end-for-end and change some wiring or whatever, then the prop could rotate the other way. So in that case, same engine could go either way. Psion fucked around with this message at 22:32 on Oct 21, 2014 |
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Oct 21, 2014 22:29
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As alluded to above, p factor and torque effects have much more effect at slow speeds where you do not have the aerodynamic forces of the wing working well to stabilise. With the high power fighters you do not put full power in quickly from any low speed normal situation as it will torque roll the aircraft. The torque effects only come in under acceleration so once settled in the cruise you don't really need trim to keep the wings level. The trim hobbesmaster is refering to is rudder trim which is used really for take off as you need it to help keep the aircraft going straight. It depends on engine rotation, CW props need right rudder on power, and anti clockwise engines need left rudder.
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Oct 21, 2014 22:31
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The Corsair has a stall strip on one wing to keep the wings stalling at the same time due to the torque of the motor.
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Oct 21, 2014 22:31
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david_a posted:Whoa. I always assumed planes with two engines had them spin in different directions. Although I guess that would make them different engines, huh? I've heard that old wives' tale told many times, but apparently it isn't true. In other news, it sounds like the Aerion supersonic business jet might have found a partner in Airbus. All of a sudden it's gone from "yeah, right" to "holy poo poo, this might actually happen".
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Oct 21, 2014 22:33
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