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| (73781) | |
Boeing jet to break distance record |
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Posted by RonInBayside on Wed Nov 9 16:29:20 2005 Boeing will attempt to fly a 777-200LR from Hong Kong to London in a flight track of greater than 12,000 miles to break a long-distance record for commercial jetliners currently held by a 747-400. The 777 will be powered by GE-90-115 engines and will have 35 people aboard. A representative of the Guinness Book of World Records will meet the plane at Heathrow Airport. |
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Re: Boeing jet to break distance record |
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Posted by Mitch45 on Wed Nov 9 16:30:21 2005, in response to Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 16:29:20 2005. How will they know if they don't have enough fuel to make it? And once they do, what can they do about it? |
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Re: Boeing jet to break distance record |
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Posted by Terrapin Station on Wed Nov 9 16:48:14 2005, in response to Re: Boeing jet to break distance record, posted by Mitch45 on Wed Nov 9 16:30:21 2005. How will they know if they don't have enough fuel to make it?Onboard computers. It's the newest thing. All the kids are doing it. And once they do, what can they do about it? Uh, land somewhere else? |
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Re: Boeing jet to break distance record |
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Posted by cortelyounext on Wed Nov 9 16:54:20 2005, in response to Re: Boeing jet to break distance record, posted by Terrapin Station on Wed Nov 9 16:48:14 2005. Nice. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Wed Nov 9 17:14:48 2005, in response to Re: Boeing jet to break distance record, posted by Mitch45 on Wed Nov 9 16:30:21 2005. Brian is correct. It's called a fuel management system. It takes into account take-off weight, temperature, altitude, engine type and throttle settings, expected tailwinds and headwinds and change in weight due to fuel burn-off. |
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| (73845) | |
Re: Boeing jet to break distance record |
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Posted by JohnL on Wed Nov 9 18:52:54 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 17:14:48 2005. Well, when you (re)learn your calculus, you can use it to solve differential equations like this one!! |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Wed Nov 9 19:11:58 2005, in response to Re: Boeing jet to break distance record, posted by JohnL on Wed Nov 9 18:52:54 2005. Yes! Would this not be in the category of Min-Max problems? |
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Re: Boeing jet to break distance record |
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Posted by Olog-hai on Wed Nov 9 19:21:17 2005, in response to Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 16:29:20 2005. And there's no more SST flying. Who cares about how far; we wanna know about how fast . . . |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Wed Nov 9 19:24:57 2005, in response to Re: Boeing jet to break distance record, posted by Olog-hai on Wed Nov 9 19:21:17 2005. Airlines care. Kerosene costs a lot of $$$ these days. |
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| (73875) | |
Re: Boeing jet to break distance record |
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Posted by Olog-hai on Wed Nov 9 19:31:42 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 19:24:57 2005. That's what happens when governments allow oil companies to run riot. Should invest in supersonic turbofans and better ramjets to save fuel . . . |
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Re: Boeing jet to break distance record |
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Posted by JohnL on Wed Nov 9 19:37:30 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 19:11:58 2005. When I played with min-max, it was just linear equations. This is a whole new level of complexity. I wonder if it’s a variation of a travelling salesman problem? |
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Re: Boeing jet to break distance record |
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Posted by Terrapin Station on Wed Nov 9 19:42:07 2005, in response to Re: Boeing jet to break distance record, posted by Olog-hai on Wed Nov 9 19:31:42 2005. Personally, I'm a big fan of SCRAMjets. |
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| (73899) | |
Re: Boeing jet to break distance record |
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Posted by Jersey Mike on Wed Nov 9 20:08:12 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 19:24:57 2005. Jets will work on just about anything, including peanut oil. |
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| (74045) | |
Re: Boeing jet to break distance record |
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Posted by American Pig on Wed Nov 9 23:03:50 2005, in response to Re: Boeing jet to break distance record, posted by Terrapin Station on Wed Nov 9 19:42:07 2005. SCRAMjets help you SCRAM faster. |
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| (74058) | |
Re: Boeing jet to break distance record |
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Posted by RonInBayside on Wed Nov 9 23:31:37 2005, in response to Re: Boeing jet to break distance record, posted by Olog-hai on Wed Nov 9 19:31:42 2005. Lockheed has been working on ramjets since the late 1940s, beginning with 1/3 scale models dropped from P-38 mother ships. Unfortunately, they have not yet lived up to promises. |
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| (74060) | |
Re: Boeing jet to break distance record |
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Posted by RonInBayside on Wed Nov 9 23:32:56 2005, in response to Re: Boeing jet to break distance record, posted by JohnL on Wed Nov 9 19:37:30 2005. That's a reasonable thought. |
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Re: Boeing jet to break distance record |
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Posted by Terrapin Station on Wed Nov 9 23:42:46 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 23:31:37 2005. The people who made the promises are dead. So yes, they have not yet lived up. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Wed Nov 9 23:43:23 2005, in response to Re: Boeing jet to break distance record, posted by Jersey Mike on Wed Nov 9 20:08:12 2005. In general, this is true, but I don't vouch for your maintenance. Some engines, like the one in the M1 Abrams, allow you to select a number of fuels.The SR-71's J85 turbojets were lit with something akinto lighter fluid. When the afterburners came on, there were right green shock diamonds. That airplane was finicky, but when you drovve it right, itcould sustain Mach 3+. It's official maximum speed reached is 2242 mph, Mach 3.4. Most experts believe it can do close to Mach 4. |
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| (74109) | |
Building Blocks to an HOTOL SSTO RLV (was:Re: Boeing jet to break distance record) |
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Posted by WillD on Thu Nov 10 02:12:24 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 23:31:37 2005. The ramjet was always so limited. It has the same problems a turbojet or turbofan has with respect to supersonic flow through the combustion chamber, but can't even get itself up to that speed by itself. All jet engines to this point have worked on the principle of taking in air, compressing it, putting fuel in it, igniting it and then hanging on as the gasses are expelled, powering the compressor and moving the aircraft forward. This is all fine and well at subsonic speeds, where none of the components are really making enough of a shockwave to knock the flame out, so you can have a massive inlet designed to admit as much air as you can possibly gulp down, and then add to that by using a second turbine set to power a massive fan at the very front, thereby creating a very efficient engine. However, as soon as you start going supersonic you need to play with the incoming air such that you don't have supersonic air through the combustion chamber. In fighters and such this is done with variable geometry inlets and ductwork leading to the engine, where hydraulically operated ramps bend the air until it slows down and increases in pressure. That works just fine until you're doing about Mach 3, where you can't slow the air down fast enough to keep the supersonic airflow from blowing the combustion chamber out. This applies for all engines to this point, be it turbofans, turbojets, or ramjets. Turbofans are in particular very picky about the air they take in, probably because of the massive fan at the front of the assembly. I know Ben Rich, former head of the Skunk Works, claimed that the the J-75 turboramjet inlets he designed for the SR-71 developed most of the power at the edges of it's flight envelope.Here's where the scramjet comes in, and as might be guessed from the acronym it simply means "Supersonic Combustion Ramjet". It's an engine which relies on air pressure alone for compression, atmospheric oxygen for the oxidizer, and is capable of performing combustion of fuels in a supersonic airstream. Up until about 2002 many aerospace engineers didn't believe a scramjet could even achieve measurable thrust. Around that time the Australians launched a tiny cylindrical scramjet on a sounding rocket which they promptly proceeded to lose. It wasn't until it was turned into local authorities that they recovered it and realized that they'd assumed the engine hadn't fired and the data logger onboard had recorded measurable thrust. Then in November of 2004 the X-43 Hyper-X achieved a speed of Mach 10 after riding a Pegasus booster to around Mach 4 and 300,000 ft. This small unmanned aircraft now lying at the bottom of the Pacific is now the fastest non-orbital vehicle in the world. Unfortunately no good deed goes unpunished and the X-43 program, including the X-43B scaled up model, the X-43C hydrocarbon burning model and the even faster X-43D (proposed for flight up to Mach 15), was scrapped as part of NASA's Vision for Space Exploration program. Fortunately there is a bright spot, the X-51 appears to be a restarting of the X-43C hydrocarbon fueled scramjet program. The X-51 is an Air Force run program, an outgrowth of their Scramjet Engine Development program. They of course have a great interest in scramjets for use in hypersonic cruise missiles, hypersonic exo-atmospheric 'skip' bombers, hypersonic recon aircraft (which they already have if you believe the Aurora hype) and perhaps even hypersonic fighters. It's good to see that scramjets aren't being shelved completely just because Dubya wants to go to the moon. However I do fear that if the Air Force team makes a great leap forward in scramjet technology this thing will be locked up at Groom Lake and NASA will never benefit from their research. Then again, it's likely the Air Force has been experimenting with scramjets for years, so perhaps the X-51 is just a convenient way to bring some of their black research into the white, 'non classified' side of aerospace. Either way, the promise of scramjets is great. The promise of a horizontal takeoff and landing single stage to orbit (HOTOL SSTO) is exactly what the shuttle promised us 25 years ago, except that these SSTOs wouldn't have the logistics tail the shuttle incurs on every flight. Being able to dispense with expensive launch facilities, use aerial refuelling to reach orbits of greatly varying inclinations, and a general increasing in flexibility when leaving earth all make these very promising vehicles. Of course an SSTO vehicle has it's downsides, as it's unnecesary to carry wings into space and bringing those wings back through the atmosphere requires a large, expensive and potentially troublesome thermal protection system. Also a scramjet provides no power in a vacuum as there's no atmosphere. A rocket based combined cycle engine or auxilliary rocket system has been explored for the transition from the roughly Mach 15 to Mach 20 (about 11,000 to 15,000mph) cutoff to the 17,000mph orbital velocity. However, the liquid oxygen which would be used by this rocket system, the rockets themselves in the case of an auxilliary rocket system, the wings and their thermal protection system would all be heavy and expensive to carry into space. To this end it might be preferable to use the current Crew Exploration Vehicle in conjunction with the SSTO. The HOTOL SSTO would carry the CEV from the ground up to something like 300,000 to 500,000 feet and between 12,000 and 15,000mph, where the CEV would pop out of the bay, fire up a LOX/Liquid Hydrogen upper stage and fly into orbit. This way the heavy wings and such never have to fly into orbit, the Scramjet doesn't have to be made to cope with the vacuum, and we don't have to squeeze liquid oxygen into what will already be a crowded airframe. |
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Re: Boeing jet to break distance record |
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Posted by BIE on Thu Nov 10 05:14:19 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 23:43:23 2005. The "Squirrels" have something faster today, I'm sure. |
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Re: Boeing jet Succeeds: Distance record broken! |
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Posted by RonInBayside on Thu Nov 10 09:09:10 2005, in response to Re: Boeing jet to break distance record, posted by BIE on Thu Nov 10 05:14:19 2005. People are talking about it, but only speculatively, pointing to the "black" programs DoD has funded.Boeing Jet Completes 12,586-Mile Flight Updated 8:34 AM ET November 10, 2005 LONDON (AP) - A Boeing Co. jet arrived in London on Thursday at the end of an attempt to break the record for the longest nonstop flight by a commercial jet. The 777-200LR Worldliner _ one of Boeing's newest planes _ touched down shortly after 1 p.m. (8 a.m. EST) at London's Heathrow Airport after an almost 23-hour journey of more than 12,586 miles from Hong Kong. The flight traversed the Pacific Ocean and North America before landing in London. Boeing said that Guinness World Records representatives would monitor the flight and attend the landing at London's Heathrow Airport. The plane has four pilots and was carrying 35 passengers and crew, including Boeing representatives, journalists and customers. Boeing wanted to fly the jet farther than a Boeing 747-400 that flew 10,500 miles from London to Sydney in 1989. The record-breaking attempt is part of Boeing's fierce competition with its European rival Airbus. The Boeing 777-200LR Worldliner was designed to compete directly with the popular Airbus 340-500, which has a flight range of 10,380 miles. After leaving Hong Kong, the Boeing jet was flying to the northern Pacific Ocean, crossing North America and cruising over the Atlantic Ocean to London, said Boeing spokesman Chuck Cadena. Hong Kong-London flights usually fly over Russia. |
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Re: Boeing jet to break distance record |
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Posted by aem7ac on Thu Nov 10 10:35:47 2005, in response to Re: Boeing jet to break distance record, posted by JohnL on Wed Nov 9 19:37:30 2005. I wonder if it’s a variation of a travelling salesman problem?Dood. Travelling Salesman is a classic problem in discrete math. It has to do with routings and minimization of paths. Not analytical functions and differential equations, which are part of differential calculus. Now that I think about it, discrete math problems can be fomulated in terms of analytic functions, I suppose, but that's advanced (beyond me) math territory and typically not the classic way to approach a DiffEq problem. You know, you could just look this up if you cared enough. AEM7AC |
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Re: Boeing jet to break distance record |
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Posted by aem7ac on Thu Nov 10 10:37:06 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 19:24:57 2005. Actually flying long range is very expensive on fuel. Think about the reasoning. It's obvious.Hint: think about the take off weight constraint. What is its relationship to payload? |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 10:45:42 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 10:37:06 2005. i disagree. Let's take a look at this:SHORT RANGE FLIGHT 1) More use of take-off power setting and thrust reversing; more taxiing 2)More time (proportionate) spent on climbing to altitude (greater fuel consumption) 3) Lower initial fuel load (so lower take-off weight) which lowers fuel consumption LONG RANGE FLIGHT 1) Heavier take-off weight (tanks completely full) so more fuel consumed on departure 2) Less time proportionately spent on take-off and landing; majority of time spent at altitude in economical cruise mode. Result: I would guess that long flights are more efficient on fuel, overall than a wshort ones. However, short flights mean you can process more cattle (I mean, carry more passengers) and therefore make more revenue, assuming demand is there. |
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Re: Boeing jet to break distance record |
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Posted by aem7ac on Thu Nov 10 11:05:55 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Thu Nov 10 10:45:42 2005. Ron, I'm no flight engineer, I've been told by the Aero/Astro types at one time what the equations are and why longer flights result in smaller payloads. Here is a presentation that explains it rather well.Basically, the non-quantitative explanation goes like this: the longer the range, the more fuel you got to carry off of the ground, and the amount of fuel you use is never going to decrease... so your take off weight is higher and therefore you need even more fuel per each pound of payload. Beyond this, you will need to solve differential equations to see how the payload relates to the take off weight and fuel weight. AEM7AC |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 11:12:34 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 11:05:55 2005. Thanks. I will look that over.Perhaps my question was a bit different: You and I each have an airplane (the same model). I can fly once per day a long-distance route; you fly 4 times per day a shorter route. (you could pose this as a function question: what happens when you fly 5 times per day, 6 etc.) Which of us, at the end of the day, burned more fuel per passenger-mile? |
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Re: Boeing jet to break distance record |
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Posted by Olog-hai on Thu Nov 10 11:14:04 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 11:05:55 2005. So jets with big turbofans are not more fuel-efficient than the older ones with smaller turbofans . . . ? Afterburners wouldn't make any difference either? Engines with greater fuel efficiency do have the greater bearing on range, because it means you need less fuel to travel over that range. |
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Re: Boeing jet to break distance record |
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Posted by JohnL on Thu Nov 10 11:15:21 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 10:35:47 2005. True and true.The fuel consumption problem is a differential equation. Deciding on what altitude to fly, and what speed to maximize the usage of a finite amount of fuel seems to me to be a (more continuous) version of the travelling salesman problem, or the knapsack problem: ie easy to find a good solution but computing an (the?) optimal solution can take an indefinite amount of time. I realize that this is not a discrete mathematics problem, but the solution pathways may be similar. |
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Re: Building Blocks to an HOTOL SSTO RLV (was:Re: Boeing jet to break distance record) |
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Posted by RonInBayside on Thu Nov 10 11:23:39 2005, in response to Building Blocks to an HOTOL SSTO RLV (was:Re: Boeing jet to break distance record), posted by WillD on Thu Nov 10 02:12:24 2005. I like your post. You're right.The SR-71 was a case of "I want to go faster if somebody would please get that air out of my way (in the engine, that is)." |
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Re: Boeing jet to break distance record |
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Posted by aem7ac on Thu Nov 10 11:24:44 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Thu Nov 10 11:12:34 2005. Perhaps my question was a bit different: You and I each have an airplane (the same model). I can fly once per day a long-distance route; you fly 4 times per day a shorter route. Which of us, at the end of the day, burned more fuel per passenger-mile?London-Boston: 3,000 miles. New York-Boston: Fly 10 times, 300 miles (for the sake of argument). To fly 3,000 miles, I might need 150,000 lbs of fuel. I have to load all this fuel up front in London. That leaves me some 250,000 lbs for payload (on a 767). To fly 300 miles, I would need about 20,000 lbs of fuel. I can load fuel each time I sit on the tarmac. So each take off on the airframe would allow 380,000 lbs of payload. Of course, you can't really fit 380,000 lbs worth of crap in a 767, unless you were flying lead or something. And there are other constraints, like runway length, and whether the freight is there, and the fixed infrastructure like seats for passengers and/or cargo compartments if a cargo plane. So, it's a very complicated function... because there are many constraints. But as a rule of thumb, you are better off flying well below the maximum design range of the plane in terms of fuel -- to get the maximum payload. Think about it for a minute. Why do freighters stop for refuel in Anchorage when flying from Midwest to the Far East, and why do passenger jets not do the same? The same planes (with a different fuselage configuration) are used on those routes. The reason short routes make more money has nothing to do with fuel and everything to do with maintenance, utilization, and most of all, travel demand. AEM7AC |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 11:27:35 2005, in response to Re: Boeing jet to break distance record, posted by Olog-hai on Thu Nov 10 11:14:04 2005. Afterburners increase power at a disproportionate increase in fuel consumption. Basically you are spraying fuel directly into the exhaust stream where it lights up from the intense heat.High-bypass engines are more fuel efficient. In fact most of the thrust is generated by the combustion core spinning the big fan and so the airplane acts more like a prop plane than a jet plane. ure turbojets are most efficient at high altitude; high-bypass turbofans are very efficient at mid-to-lower altitudes, where you burn the most fuel (that is, taking off and climbing to your cruise altitude). They are also quite efficient at the cruise altitude. |
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Re: Boeing jet to break distance record |
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Posted by aem7ac on Thu Nov 10 11:29:22 2005, in response to Re: Boeing jet to break distance record, posted by JohnL on Thu Nov 10 11:15:21 2005. Deciding on what altitude to fly, and what speed to maximize the usage of a finite amount of fuel seems to me to be a (more continuous) version of the travelling salesman problemIt can be thought of in these terms, except that most people forget that the minimization problem relies on having on advance knowledge of the conditions you would encounter and therefore there is a deterministic solution. Travelling salesman is not trying to cross a bunch of bridges or visit a set of clients that are continuously moving and appearing and disappearing at random. Planes are flying through weather that changes and for which there is no advance information... and because you can't predict weather variables like tail wind and windspeed with any degree of accuracy required for a fuel optimization calculation, you can't do a fuel optimization calculation in advance. But yes, it's the same type of optimization problem, except that one is continuous and one is discrete. AEM7AC |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 11:36:39 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 11:24:44 2005. You make a good point there. The freighters make the stop because they are crammed full of stuff and the cargo operators put less fuel in the airplane.Also, a cargo container doesn't write to the airline complaining about having to endure a refueling stop, whereas that is not true for a passenger (so that's a customer service issue). "The reason short routes make more money has nothing to do with fuel and everything to do with maintenance, utilization, and most of all, travel demand." Well, I wouldn't go that far. Yes, you are turning the seat over more (therefore charging more tickets) and assuming you can fill the plane, you increase revenue that way. The marginal cost in fuel for each passenger added is small. So utilization is very important. Good point by you. But short flights do involve a higher percentage of time spent in inefficient flight (take-off settings, thrust reversing and climbing and taxiing) They also stress the airplane more because you are cycling the engines more, you are pressurizing and depressurizing the fuselage much more often, you need to clean the airplane more often, and so on. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 11:39:36 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 11:29:22 2005. Well, you can know the range of conditions you're likely to encounter. You can't know everything about the weather in a locale, but you know the pattern from having collected data from the last 50 years. You also know the geography and how that affects things. |
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Re: Boeing jet to break distance record |
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Posted by Peter Rosa on Thu Nov 10 11:56:15 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 11:24:44 2005. The reason short routes make more money has nothing to do with fuel and everything to do with maintenance, utilization, and most of all, travel demand.Southwest Airlines has built itself into the most successful airline in the United States (and arguably the world) by flying primarily shorter routes. My LIRR/NYCT blog |
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Re: Boeing jet to break distance record |
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Posted by R68A - 5200 on Thu Nov 10 12:19:24 2005, in response to Boeing jet to break distance record, posted by RonInBayside on Wed Nov 9 16:29:20 2005. They're GE90-110B1s. |
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Re: Boeing jet to break distance record |
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Posted by R68A - 5200 on Thu Nov 10 12:33:51 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 11:24:44 2005. It is cheaper to fly one long non-stop flight. Rather then multiple flights. The fuel stop wastes money. Your plane will end up on the ground not doing anything while it fuels. You will waste more fuel taking off multiple times. Say it takes about 150nm to reach the top of cruise. You're better off burning 10000lbs/hr on a 767 for that 150nm then more than burning twice as much as that and traveling at a slower ground speed too. You also put alot of extra cycles on the airframe. The reason cargo flights stop in Anchorage is because cargo weights ALOT more then passengers. Cargo planes are generally loaded right up to the Maximum Zero Fuel Weight before going. They exist to get things from point A to point B and they will want to get as much in there as they can and so they are designed so. A 747-400 Freighter has a MZFW of up to 635,000lbs. A passenger 747-400 on the other hand 542,500lbs. When a plane gets converted for freigher service, it's not only a simple reconfiguration of the cabin, but also strengthening of the deck floors and wings and gears for these more intensive applications. Think about it, on a passenger plane, the space between the heads and the bins are empty space. On a freighter, it's filled with pallets and/or containers that are the height of the cabin. |
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Re: Boeing jet to break distance record |
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Posted by R68A - 5200 on Thu Nov 10 12:35:37 2005, in response to Re: Boeing jet to break distance record, posted by R68A - 5200 on Thu Nov 10 12:33:51 2005. For a reference, the MZFW for a 763ER and a 763F is 295klbs and 309klbs respectively. |
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Re: Boeing jet to break distance record |
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Posted by R68A - 5200 on Thu Nov 10 12:39:18 2005, in response to Re: Boeing jet to break distance record, posted by R68A - 5200 on Thu Nov 10 12:33:51 2005. Forgot to add: The freighters are heavier and can thus hold less fuel. There's is the Asiana 222/221 flight combination from South Korea to JFK. While published as non-stop flight, if they decide to put a 747-400M (main deck is 1/2 cargo and 1/2 passengers), there will be a fuel stop at ANC because of the extra weight. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 12:45:41 2005, in response to Re: Boeing jet to break distance record, posted by Peter Rosa on Thu Nov 10 11:56:15 2005. Yes, but that's not the whole story. First, Southwest dispensed with hub and spoke system. Second, they fly only 737s, siimplifying maintenance and reducing purchase costs, and need fewer flight attendants per plane. Third, they hedge fuel like crazy and their hedges have Southwest buying fuel at the lowest cost of any airline. Fourth, they are non-union if I recall correctly. Fifth, they serve no food or very little.So the shorter routes, per se, were not the key to success; they are one piece of the overall strategy. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 12:46:23 2005, in response to Re: Boeing jet to break distance record, posted by R68A - 5200 on Thu Nov 10 12:19:24 2005. I thought they were GE-90-115s. |
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| (74227) | |
Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 12:47:40 2005, in response to Re: Boeing jet to break distance record, posted by R68A - 5200 on Thu Nov 10 12:35:37 2005. Excellent posts by you. Thanks. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 12:51:42 2005, in response to Re: Boeing jet to break distance record, posted by R68A - 5200 on Thu Nov 10 12:39:18 2005. "The freighters are heavier and can thus hold less fuel"Excellent point - I actually missed that one. This is one reason the Airbus A380 Freighter is in trouble. The prototype A380 is flying, but it is overweight already and is not achieving the fuel efficiency or range Airbus promised (and this is before any payload is added). It's had multiple problems, including main gear that could not deploy from the wheel well. |
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Re: Boeing jet to break distance record |
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Posted by WillD on Thu Nov 10 12:58:05 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Thu Nov 10 11:27:35 2005. I believe a bypass turbofan's effectiveness becomes greater with an increasing bypass ratio and decreasing pressure at the blade tip of the fan. It was from this theory that the Propfan was developed, the basic idea being that the bypass ratio would be much greater for an unshrouded fan than for one within the engine nacelle as on a conventional turbofan. For a while both Boeing and McDonnell Douglas were prepared to offer propfans on their next offering of small to medium sized airliners, MDC was planning on the MD-90 and 95 using them while Boeing was devising a brand new airliner with tail mounted engines they dubbed the 7J7. Both engines for the new airliners had more than their fair share of teething problems and with the sudden glut of fuel prices in the mid 1980s the program was scrapped. Once again a program for saving fuel begun in the 1970s was scrapped in the 1980s due to fuel prices dropping, much to our great sadness in these days of rising fuel prices.In the end the failure of the propfan program may have lead to Airbus getting it's foot truely in the door of the US airliner market. The airlines at the time were getting anxious to replace their aging DC9s and 737-200s with something newer, or at least supplement their old aircraft with something a bit more modern. Because Boeing and MDC had their light to medium capacity airliner expenditures taken over by their propfan airliner programs, they were in no position to offer an improved DC9 or 737. Into this gap stepped Airbus, with their A320, which airlines had been gunshy about with it's new fly-by-wire system and somewhat controversial V2500 engines. Left with no choices from Boeing or MDC the airlines pretty much had to purchase A320s or face mass obsolesence of their turbojet powered 737-200s and DC9s in the coming years with no suitable replacement. Both manufacturers tried to hold off the airline's Airbus purchases with promises of great fuel savings from the propfanliners, but with fuel prices then falling it was a hollow argument to airliners looking for much more than either company was offering. In the end both Boeing and MDC retreated from propfans, going instead to far more conventional designs. Boeing simply upgraded the 737 series with CFM56 turbofan engines and an improved cockpit producing the -300, the lengthened -400, and the shortened -500. McDonnell Douglas scrapped their propfan program and the MD90 was equipped with the same turbofans which the prior MD80 had recieved. |
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Re: Boeing jet to break distance record |
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Posted by Peter Rosa on Thu Nov 10 12:59:26 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Thu Nov 10 12:45:41 2005. Yes, but that's not the whole story [behind Southwest's success]. First, Southwest dispensed with hub and spoke system.Correct. Second, they fly only 737s, siimplifying maintenance and reducing purchase costs, and need fewer flight attendants per plane. They need the same number of FA's per aircraft as any 737 operator. FAA requires a specific number for safety purposes. Third, they hedge fuel like crazy and their hedges have Southwest buying fuel at the lowest cost of any airline. Correct again. Fourth, they are non-union if I recall correctly. True, but their pay scales are comparable to other, unionized airlines. Fifth, they serve no food or very little. You might say they started an industrywide trend :) My LIRR/NYCT blog |
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Re: Boeing jet to break distance record |
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Posted by aem7ac on Thu Nov 10 12:59:37 2005, in response to Re: Boeing jet to break distance record, posted by RonInBayside on Thu Nov 10 12:51:42 2005. "The freighters are heavier and can thus hold less fuel"But not by much. The main reason freighters are heavier is because of the freight they hold, not because of the structural members that are added to strengthen the fuselage. R68A posted a number in the last post... it's something like a 20% extra empty weight, which is significant when you are flying stuff in air, and will affect the range... but it's not THAT MUCH heavier. I think it's still a fair statement to say that are similar planes that fly the routes. I would contend the reason the freighters are designed that way is BECUASE the reduced range will help them achieve the extra cargo capacity, and not the other way round (i.e. not that they WANTED a shorter range and HAPPEN to find that it carried more stuff.) AEM7AC |
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Re: Boeing jet to break distance record |
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Posted by mr_brian on Thu Nov 10 13:43:33 2005, in response to Re: Boeing jet to break distance record, posted by R68A - 5200 on Thu Nov 10 12:35:37 2005. Welcome back, Ed. |
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Re: Boeing jet to break distance record |
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Posted by WillD on Thu Nov 10 14:30:41 2005, in response to Re: Boeing jet to break distance record, posted by aem7ac on Thu Nov 10 12:59:37 2005. In some cases the floor of an air freighter may well be reinforced. I know Evergreen International somewhat loudly advertized their reinforced floor 747s as an alternative to the An124 when it was beginning to take their business away. A regular package freighter still stands to weigh more than a passenger flight since it's filling more of the volume with weight. UPS, FedEx and Airborne Express manage to pack the containers pretty tight, and those containers are designed to fit nearly exactly into the plane, leaving little empty volume. As such the package carrier can leave with partially filled tanks in order pack the plane with more cargo while accepting the penalty of stopping for fuel at some point. As another poster said, your package doesn't particularly care if it sits on the tarmac for 15-20 minutes in Anchorage, but you sure as hell might if a direct flight was an option. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 16:43:08 2005, in response to Re: Boeing jet to break distance record, posted by WillD on Thu Nov 10 12:58:05 2005. Your history is pretty accurate. Note, however that the CFM-56 is a very efficient engine in its own right (it's now a best seller and it powers Airbuses as well as Boeing planes).The CFM-56 is GE's B-1 bomber engine core, minus afterburner, mated to a SNECMA fan and gearbox, with electronic fuel management. |
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Re: Boeing jet to break distance record |
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Posted by RonInBayside on Thu Nov 10 16:44:31 2005, in response to Re: Boeing jet to break distance record, posted by Peter Rosa on Thu Nov 10 12:59:26 2005. When I mentioned stewardesses, it was in the context of not flying, say 767s and overstaffing (flying a larger plane with fewer people on it. |
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