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ikramerica
Posts: 15197
Joined: Mon May 23, 2005 9:33 am

### RE: 777-LR To Be Lightened By 7 Tons

The best places in the structure to save weight are in the tail, wingbox, wing, cockpit, main deck floor, lower deck floor, cargo doors, pax doors, cargo conveyance systems, and engine enclosures. But doing a CFRP fuselage barrel would change everything. You can bolt on a new cockpit section or new tail section to the existing Al fuse (with modification, of course).

 Quoting GoCOgo (Reply 63):Sorry to say, but with my civil engineering education, when you get into more complex units and relationships, metric conversions quickly become just as messy as US units.

Very true. Same experience for me in my CE degree. NEITHER one is simple, both are convoluted to some degree. Both start with a basic idea and then grow from there:

1 pound of water = 1 pint of water
1 ml of water = 1 g of water
metric ads another equivalence 1cc = 1ml

But none of that makes it simple, really. Relatability makes things simple.

People average between 5' and 6' tall, and being able to break that down into feet and inches makes it relatable. Saying people range from 1.525 to 1.825 meters and having that mean something is a much harder sell...

No, it's about 2.2lbs/kg. You are arguing one of the most common conversions we learn? Why?

 Quoting Geniusjacky (Reply 80):When even though we have 75 and 76, seriuosly, could your really tell. Turning the thermostat, it's either 70 or 75 or 80 to me.

That's because you are impatient. You can easily feel the difference between 75 and 76 in your home if you allow the system to actually bring your house to the new temp. I make one F changes all the time on my digital thermostat, and it makes a difference.

 Quoting Jacobin777 (Reply 91):open any math/chemistry/physics textbooks, and they are all in the metric system...

You might want to open on first to see the proper conversion factors, then read further to see they do problems in both in physics text books. In chemistry, usually not, and in math? Math is not about using metric or imperial units. Examples might have either/or, but they need not have units at all!

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Ikramerica (Reply 100): No, it's about 2.2lbs/kg. You are arguing one of the most common conversions we learn? Why?

my bad..that was a typo...its actually 2.205 and those numbers become very important when they are multiplied by a factor of tens of thousands..hence me putting it there....

 Quoting Ikramerica (Reply 100):You might want to open on first to see the proper conversion factors, then read further to see they do problems in both in physics text books. In chemistry, usually not, and in math? Math is not about using metric or imperial units. Examples might have either/or, but they need not have units at all!

say what you talking about? Open up any chemistry book...and what do you get....ml (metric), cm^3 (metric), liters (metric), angstroms (metric), moles (metric).....etc...etropy, enthalpy, Gibbs free energy..all metric values given...

physics....e=mc^2 (metric), f=ma/w=mg ie.force(metric), guaussian curves in a chaged particle (metric), electricity (metric)...what ISN'T given in the metric system?

If had put "US-units" in any of my physics or advanced chemistry classes, I would certainly points taken off....very rarely does one see "US-unites" such as lbs, gallons, degrees F, etc.

math/calculus-yes, standard mathematics doesn't use metric/us system..however, when there are "applied" mathematic problems, many texts tend to use metric-system values......

texfly101
Posts: 343
Joined: Fri Jan 06, 2006 6:42 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting OzGlobal (Reply 98):No, you Americans use the British system. Sorry to break it to you.

good one...

MakeMinesLAX
Posts: 482
Joined: Thu Dec 18, 2003 4:22 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 101):physics....e=mc^2 (metric), f=ma/w=mg ie.force(metric), guaussian curves in a chaged particle (metric), electricity (metric)...what ISN'T given in the metric system?

Formulae such as the ones you've indicated are inherently neutral with regard to measurement systems - you can plug in any values as long as they are from the same system. Even though the newton is a metric unit of force, Newton's F=ma was conceived before the metric system.

Boy, this has strayed a light-year (BTW, a system-neutral measurement) away from the original topic. Maybe we can get back on track by discussing which type of nautical mile will be used in the quoted figure for the range increase which will result from the seven-ton weight reduction!

atmx2000
Posts: 4301
Joined: Wed Oct 13, 2004 4:24 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting MakeMinesLAX (Reply 103):Boy, this has strayed a light-year (BTW, a system-neutral measurement) away from the original topic.

I think Martians have a different value for a light-year.

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting MakeMinesLAX (Reply 103):Formulae such as the ones you've indicated are inherently neutral with regard to measurement systems - you can plug in any values as long as they are from the same system. Even though the newton is a metric unit of force, Newton's F=ma was conceived before the metric system.

its called the de facto standard mate...

goCOgo
Posts: 710
Joined: Mon Jan 17, 2005 11:24 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 101):say what you talking about? Open up any chemistry book...and what do you get....ml (metric), cm^3 (metric), liters (metric), angstroms (metric), moles (metric).....etc...etropy, enthalpy, Gibbs free energy..all metric values given...

Perhaps we have different textbooks, but mine all had around a 50/50 mix. But many of my engineering textbooks were US only

 Quoting Jacobin777 (Reply 101):If had put "US-units" in any of my physics or advanced chemistry classes, I would certainly points taken off....

And many of my engineering profs would have taken off points for metric units (in fact, without rederiving a number of empirical formulas, most structural design problems couldn't be done in metric). This is an example of instructor bias, not superiotity or more universal acceptance of a system of units.

 Quoting Jacobin777 (Reply 101):physics....e=mc^2 (metric), f=ma/w=mg ie.force(metric), guaussian curves in a chaged particle (metric), electricity (metric)...what ISN'T given in the metric system?

Um, formulas (particularly mathematically derived ones like f=ma) are not unit dependant. Some are empirically derived from experimentation and require certain units, but they can always be rederived for any system you want. Plus, more modern units, like ohms, farads, siemens, etc. are really neither metric or english. Since certain scientists quantified them after metric was created, so they were adopted by both systems. What does an ohm equal to in a multiple of ten to a metric quantity? Nothing I know of, so it would seem this isn't a derived metric unit.

geniusjacky
Posts: 32
Joined: Sat Jun 10, 2006 8:22 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting GoCOgo (Reply 106):And many of my engineering profs would have taken off points for metric units (in fact, without rederiving a number of empirical formulas, most structural design problems couldn't be done in metric). This is an example of instructor bias, not superiotity or more universal acceptance of a system of units.

Um....Not too sure about that. While I know in construction, most architechturer/ civil engineers use english unit, I never heard of using English in other areas. Being computer engineer, obviuosly, metric is the only choice for me. However, I do know like mechanical and aerospace, they use metric extensively. In math, it depends on the textbook. I was pissed one time when the book give english unit when I only knew g = 9.8 m s^-2.....

Anyway, if the 772LR could save 7 tons/tonnes? would really make a big difference. But I seriously doubt if they would put that to all newly made 777. It definitely costs more and the difference for airline to handle the same plane with different materials would just be a pain. Probably just the few birds QF would order.

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting GoCOgo (Reply 106): Perhaps we have different textbooks, but mine all had around a 50/50 mix. But many of my engineering textbooks were US only

..

 Quoting GoCOgo (Reply 106): And many of my engineering profs would have taken off points for metric units (in fact, without rederiving a number of empirical formulas, most structural design problems couldn't be done in metric). This is an example of instructor bias, not superiotity or more universal acceptance of a system of units.

 Quoting GoCOgo (Reply 106): Um, formulas (particularly mathematically derived ones like f=ma) are not unit dependant.

However, after the derivations are done (yuck, I detested derivations), problems are solved/values given using metric values....

 Quoting GoCOgo (Reply 106): Some are empirically derived from experimentation and require certain units, but they can always be rederived for any system you want. Plus, more modern units, like ohms, farads, siemens, etc. are really neither metric or english. Since certain scientists quantified them after metric was created, so they were adopted by both systems. What does an ohm equal to in a multiple of ten to a metric quantity? Nothing I know of, so it would seem this isn't a derived metric unit.

of course any "accepted" designated unit can be given...yet they are still given in metric units...such as "decifarad", "micro-oms", etc....

classical as well as quantum physics (and chemistry) follow International System of Units (SI)....which are all basically given in metric units...

http://physics.nist.gov/cuu/index.html

[Edited 2006-07-20 04:09:15]

nitrohelper
Posts: 413
Joined: Tue Mar 08, 2005 5:32 am

### RE: 777-LR To Be Lightened By 7 Tons

I still think the ten fingers method is the best. Must be a British system as it was used before the USA existed ? I guess the Greeks and Romans used it too.
Oh yeah the Egyptians,that's it !
"Horus hurry up with those next ten blocks ,or we won't get this pyramid finished on time". "Those passage way guys are screwing up the critical path, we are getting behind on the EIS date"!

Are we far enough off topic now?

dank
Posts: 935
Joined: Thu Jul 20, 2006 11:35 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Ikramerica (Reply 100):People average between 5' and 6' tall, and being able to break that down into feet and inches makes it relatable. Saying people range from 1.525 to 1.825 meters and having that mean something is a much harder sell...

But don't you think that the 5' to 6' average height is a construct because it happens to be the integer units of height Americans are used to? My guess is that my European friends would not choose the metric euivalent to this, but maybe 150 to 180 cm? which doesn't convert well to english units?

 Quoting GoCOgo (Reply 106):Um, formulas (particularly mathematically derived ones like f=ma) are not unit dependant. Some are empirically derived from experimentation and require certain units, but they can always be rederived for any system you want. Plus, more modern units, like ohms, farads, siemens, etc. are really neither metric or english. Since certain scientists quantified them after metric was created, so they were adopted by both systems. What does an ohm equal to in a multiple of ten to a metric quantity? Nothing I know of, so it would seem this isn't a derived metric unit.

This isn't quite true, because many units were designed based on distances and forces, and therefore are, in fact, somewhat dependent on one unit of measure.

I actually have an undergrad and advanced degree in physics, and it is true that you do see some english units (slugs for mass comes to mind0. However, this may stem from the fact that faculty learned in these units and that many texts have not been update) (for example, the classical mechanics text i used which was a standard was written in the 50s) because classical mechanics and electrodynamics haven't really changed.

In fact, in physics the real conflict is between kms (kiliogram, meter, seconds) units and cgs (centimeter, gram, seconds) units. SI uses kms and most people think in them (for example, joules and newtons). However, you see cgs units in things like quantum mechanics much more frequently (the equivalent dynes and ergs)

Sorry for the off topic first post!

cheers.

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Dank (Reply 110): Sorry for the off topic first post!

-Welcome to A.net...

-and supporting my views..

sllevin
Posts: 3314
Joined: Wed Jan 30, 2002 1:57 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting SNATH (Reply 4):Would a 7 ton lighter B777LR be able to reach nirvana? (i.e. LHR-SYD with no restrictions?).

Probably. Pax are considered to weigh 210 pounds if they are adults, for planning purposes.

This would add almost 67 passengers. Word was that the 777LR could get the job done with 190-200 pax until now. So this pushes it closer to 260, which should be enough density to get the job done.

If so, I'd expect an order from BA as well.

Steve

zvezda
Posts: 8886
Joined: Sat Aug 28, 2004 8:48 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting MakeMinesLAX (Reply 103):this has strayed a light-year (BTW, a system-neutral measurement) away from the original topic.

The metric units of time were the only part that didn't catch on. There were 10 hours in a day and 100 minutes in an hour. I seem to recall ten days per week. I'm not sure about months or years.

dank
Posts: 935
Joined: Thu Jul 20, 2006 11:35 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 111):-Welcome to A.net...  -and supporting my views..

Thanks a bunch. Glad i could contribute something

cheers.

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Sllevin (Reply 112): If so, I'd expect an order from BA as well.

If anything, I would see BA dropping this route entirely (they have already dropped LHR-MEL), especially when all of the A380's come on board...many of the carriers plan on flying the "Kangaroo Route", which might decline yields....

aWombat
Posts: 20
Joined: Mon Apr 17, 2006 9:46 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting PolymerPlane (Reply 53): Not quite, 772LR has a range of 9420NM at typical payload of 301pax and their luggage. The problem of SYD-LHR is not the distance but the prevailing head winds. 772LR is capable of making the run 80% of the year. It was not enough for QF

I think that Qantas don't want to be making a hole in Western Australia the other 20% of the time. You cannot make a schedule where sometimes you get all the way and sometimes you don't. I expect it would be expensive to divert to make a 'splash & go' and would eat up any savings there were for doing the flight in a single hop.

Personally I am a bit doubtful of 22 hours on a plane. I done SYD-LHR a few times and I will e breaking it at SIN or BKK in the future if possible.

[Edited 2006-07-20 06:06:33]

atmx2000
Posts: 4301
Joined: Wed Oct 13, 2004 4:24 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting GoCOgo (Reply 106):Plus, more modern units, like ohms, farads, siemens, etc. are really neither metric or english. Since certain scientists quantified them after metric was created, so they were adopted by both systems. What does an ohm equal to in a multiple of ten to a metric quantity? Nothing I know of, so it would seem this isn't a derived metric unit.

An Ohm is a 1 Volt·Amp-1 = 1 (Joule·Coulomb-1)·(Coulomb·s-1)-1 = 1 (kg·m2·s-2)·Coulomb-1·Coulomb-1·s = 1 kg·m2·s-1·Coulomb-2

Certainly is based on base metric units, and resistances are commonly prefixed with mega, kilo, giga, etc.

dank
Posts: 935
Joined: Thu Jul 20, 2006 11:35 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Atmx2000 (Reply 117):An Ohm is a 1 Volt·Amp-1 = 1 (Joule·Coulomb-1)·(Coulomb·s-1)-1 = 1 (kg·m2·s-2)·Coulomb-1·Coulomb-1·s = 1 kg·m2·s-1·Coulomb-2 Certainly is based on base metric units, and resistances are commonly prefixed with mega, kilo, giga, etc.

i wasn't explicit in my (dependent on distances and forces) comment above.

All that aside, my guess is that there is a lot in engineering that is kept in units of convenience because that's what all of the older work used.

That aside, from looking at the airbus website, it does look at first glance that they they use metric and convert to english, not the other way around. a good check would be whether they use metric distances between pieces of the plane and the size of bolts, etc. which i would assume are all metric.

cheers

lightsaber
Moderator
Posts: 23363
Joined: Wed Jan 19, 2005 10:55 pm

### RE: 777-LR To Be Lightened By 7 Tons

On topic, SYD-LHR is a premium market that could justify a non-stop. I also see QF needing a plane that can do SYD-JFK (possible?) and SYD-DFW. Let's face it, LAX doesn't need closely paired 747 flights to SYD (is that only high season?). Don't get me wrong, I love LA, but LAX... needs work. Much of my travel from LA on AA requires a connection... usually through DFW (but sometimes ORD). I have to imagine 10 to 15% of the SYD to LAX traffic then hops to DFW and then on to their final destination. Why not skip that second hop?

Also, a 7 ton weight loss will make the A350's EIS a *little* tougher. Why? A little less pressure to replace late build 777's. Ok, I admit it might not be enough to matter.

But I'd have to imagine a 7ton lighter 772F would be a very attractive idea. Query: Is it enough of a weight loss to make a 773F attractive? I would doubt it, but someone like widebodyphotog would know the answer better than I. But if the 772F was made that little bit better... would it not allow Boeing to run the last few years of that line nearly pure freighters? (a la 744). Thus mitigating the impact of the A350 prior to Y3 launch?

Off topic:

 Quoting Dank (Reply 118):english, not the other way around. a good check would be whether they use metric distances between pieces of the plane and the size of bolts, etc. which i would assume are all metric.

Boeing spaces ribs in the plane 20" apart. Last I heard, they'll do the same thing in the 787 (but correct me if I'm wrong). Bolts and such are all "standard" sizes. I don't like engineering in standard, but the unit conversions are practically automatic now.    My college was mostly metric... but that's not the US aerospace industry (yet). However, its really tough to convert from "standard" to metric bolts, wrenches, etc. All of the tools need to be for one standard or the other. (Imagine trying to adjust a power tool only to find out its blade holder turns with a 9/16" wrench and you have a tool chest of metric wrenches... not very convienient, eh?) I work aerospace and the most common bolt remains the good old 1/4-28 in high vibration environments and the old tried and true 1/4-20 is common too. (My project is high vibration, so we mandated fine threads or 1/4-28, 1/2-20, etc.)

Most metric bolts are course thread... a quick summary:

Lightsaber

atmx2000
Posts: 4301
Joined: Wed Oct 13, 2004 4:24 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Lightsaber (Reply 119):Boeing spaces ribs in the plane 20" apart. Last I heard, they'll do the same thing in the 787 (but correct me if I'm wrong).

I thought an increase was allowing for larger windows.

In other news:

LONDON -- With Airbus deciding to take on both Boeing's 787 and 777 with one new airplane, The Boeing Co.'s commercial airplanes boss said Wednesday that the company will do much more in the next few years to make the 777 even better.

"From what we have seen, continuously improving the 777 will be our strategy in the near future," said Alan Mulally, president and chief executive of Boeing Commercial Airplanes.

Technology being developed for the 787 will find its way onto the 777, which the company has no plans to replace, he said.

.....

In the interview with the Seattle P-I, Mulally made it clear that Boeing will not stand still while Airbus develops the A350.

The 777 engines and systems can be improved, he said. There will be opportunities to use more composite material, as well as more titanium and new alloys of aluminum.

...

Mulally noted that Boeing "has a lot of time" to make these improvements.

The first of what eventually will be three Airbus A350 family members won't be available until 2012. The final A350 version won't enter airline service until 2014. Boeing plans to do a lot with the 777 during those eight years.

"We will end up with a very competitive airplane," Mulally said.

Airbus certainly puts themselves in a more difficult position with their long development cycles.

dank
Posts: 935
Joined: Thu Jul 20, 2006 11:35 am

### RE: 777-LR To Be Lightened By 7 Tons

Lightsaber, spot on both on the on topic comments and the off topic comments. The question with regards to getting the 772LR to do the Sydney - London flights nonstop with good yields hinges on whether those savings can also be translated to other sales (and what the cost to do so is). It's not as if Airbus is going to manage to get the 345 to do it any better as is. The 7 tons on the freighter is an interesting thought. Although, it would depend on what systems get lightened (i.e. whether they affect both passenger and freighter versions or not). But if Boeing can manage this it could hold off the pressure from the 350 for a while longer.

As for my metric remarks, sorry for the confusion. I meant to be referring to airbus with that because there had been some comments early on (i think) that airbus would also use english units to use older data. i just have to imagine that they use metric for most stuff (of course that could make integrating parts from different countries sort of interesting). i have spent most of my life in the US, but spent some of my formative years in Switzerland and still don't understand the english system conversions! i can do inches into feet and feet into yards (and quarts into gallons   ), but most of it still baffles me. about the only thing i do prefer is temperature in degrees F for weather, just seems more natural to me.

cheers

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Lightsaber (Reply 119):. I also see QF needing a plane that can do SYD-JFK (possible?) and SYD-DFW.

SYD-JFK is possible right now with the -200LR and with a 7-tonne (darn it, which one are they using..lol) reduction, it would probably to well..

however, QF have stated they don't want any -200LR's for JFK/DFW unless they can't get the Kangaroo Route nonstop..that's really the thick of it.....

I'm still hopin' Boeing will be able to bring the weight down enough for it to become economically feasible..

dank
Posts: 935
Joined: Thu Jul 20, 2006 11:35 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 122): SYD-JFK is possible right now with the -200LR and with a 7-tonne (darn it, which one are they using..lol) reduction, it would probably to well.. however, QF have stated they don't want any -200LR's for JFK/DFW unless they can't get the Kangaroo Route nonstop..that's really the thick of it..... I'm still hopin' Boeing will be able to bring the weight down enough for it to become economically feasible..

And that is probably wise. I would think it would be hard to justify getting a new type in the fleet simply for those two flights. But they would make good choices if they were going to buy into the 772lr anyway (for the route they really want them for).

i do, though, wonder, how many other sales they gain (or don't lose down the line to airbus) by this lightening program (unless they also contribute to this 'how we will make the 777 better' strategy boeing is talking about today) vs. how much it will cost (i.e. if they don't make a profit from it, they aren't likely to lose qantas anyway, so what have they gained, if there aren't any other benefits to it... just a thought, though.

cheers.

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Dank (Reply 123): i do, though, wonder, how many other sales they gain (or don't lose down the line to airbus) by this lightening program (unless they also contribute to this 'how we will make the 777 better' strategy boeing is talking about today) vs. how much it will cost (i.e. if they don't make a profit from it, they aren't likely to lose qantas anyway, so what have they gained, if there aren't any other benefits to it... just a thought, though.

with the -200F also (as well as the -300ER) being on the same platform as the -200LR, improvements one one will help improvements on the other....so its in Boeings best interest to make improvements....

SJCRRPAX
Posts: 961
Joined: Wed Dec 21, 2005 2:29 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 101):If had put "US-units" in any of my physics or advanced chemistry classes, I would certainly points taken off....very rarely does one see "US-unites" such as lbs, gallons, degrees F, etc.

To keep the off topic stuff going, I learned both in Engineering School. As a matter of fact, the easiest part of any engineering problem I ever had was converting from one unit to another. Maybe I'm bi-lingual, but It has always been my opinion that any student who couldn't convert from one measurement system to another in his sleep was in the wrong major. Switching units is trivial, and American Units are defined exactly with respect to Metric units. IT has never really mattered to me one way or the other, but I must say a dozen is a very good number. Its divisable by 1,2, 3, 4, 6, and sometimes 8 and 9 (if you can break the cookies up). So for many things a dozen is far better than 10.

dank
Posts: 935
Joined: Thu Jul 20, 2006 11:35 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting SJCRRPAX (Reply 125):To keep the off topic stuff going, I learned both in Engineering School. As a matter of fact, the easiest part of any engineering problem I ever had was converting from one unit to another. Maybe I'm bi-lingual, but It has always been my opinion that any student who couldn't convert from one measurement system to another in his sleep was in the wrong major. Switching units is trivial, and American Units are defined exactly with respect to Metric units. IT has never really mattered to me one way or the other, but I must say a dozen is a very good number. Its divisable by 1,2, 3, 4, 6, and sometimes 8 and 9 (if you can break the cookies up). So for many things a dozen is far better than 10.

I think everything should be able to take the natural log of everything  . But seriously, the reason that it is convenient for the units to match up without conversions is that you don't have to carry the conversion with you. It saves a lot of mistakes by not having the extra terms in the math. makes simplifying equations a breeze. Besides the fact that it makes it easy to keep track of all the units. besides the fact that i can readily remember many of the conversions, even though i graduated nearly 10 years ago and am not in a field remotely related to physics or engineering. I honestly find the SI metric system to be quite beautiful. but it must be in the inner geek in me  .

cheers.

dank
Posts: 935
Joined: Thu Jul 20, 2006 11:35 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 124):with the -200F also (as well as the -300ER) being on the same platform as the -200LR, improvements one one will help improvements on the other....so its in Boeings best interest to make improvements....

wasn't even thinking about the 773 when i posted that. stupid me. My thoughts vis a vis the -200f vs. -200lr is whether the weight savings go mainly to passenger specific features rather (although, how you could drop 7 tons or tonnes of whatever type from just those systems is beyond me), then it might not impact the freighter dramatically...

saving sales for the 300er is obviously key for boeing to delay y3 so they can get y1 right. and if anything demonstrates why it is important to have at least two strong competitors in the market, this is it. without competition, there would be no drive for improvements or to lower costs. here's hoping to see both boeing and airbus succeed.

cheers.

sllevin
Posts: 3314
Joined: Wed Jan 30, 2002 1:57 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting AWombat (Reply 116):Personally I am a bit doubtful of 22 hours on a plane. I done SYD-LHR a few times and I will e breaking it at SIN or BKK in the future if possible.

See, I think that the stop is horrid. Nothing worse than having to be woken up, get awake, land, kill a couple of hours, then get back on the plane.

Even when you have access to MH's First Class Lounge at KUL, it's a galatic pain in the rear. Give me the non-stop every day.

Steve

widebodyphotog
Posts: 885
Joined: Wed Jun 30, 1999 9:23 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Lightsaber (Reply 119):Boeing spaces ribs in the plane 20" apart. Last I heard, they'll do the same thing in the 787 (but correct me if I'm wrong). Bolts and such are all "standard" sizes. I don't like engineering in standard, but the unit conversions are practically automatic now.

Actually Boeing uses 20 inch basic frame spacing for 737, 757, and 747, 21 inch frame spacing for 767 and 777, and 24 inches for 787.

 Quoting Lightsaber (Reply 119):But I'd have to imagine a 7ton lighter 772F would be a very attractive idea. Query: Is it enough of a weight loss to make a 773F attractive? I would doubt it, but someone like widebodyphotog would know the answer better than I. But if the 772F was made that little bit better... would it not allow Boeing to run the last few years of that line nearly pure freighters? (a la 744). Thus mitigating the impact of the A350 prior to Y3 launch?

That degree of lightening for 777F would be nice but I don't think 7t is very likely. The freighter needs the beefier structure to cope with high ZF and landing weights. The -200LR does not need the structure especially as projected service loadings are well under the physical limits of the airplane...

2-3t for the 777F seems more likely reduction in weight by using material replacement and advanced manufacturing methods in key areas. This weight reduction would allow increased payloads while maintaining range and lighter operational TOW's that reduce fuel burn by a bit.

As for a 777-300F? Right now the structure would have to get much stronger, i.e. heavier to provide a commensurate increase in payload relative to the volume of -300ER. A -300F would add six pallets on the main deck and four below. To complement this volume increase payload would have to go up by 25t! I don't think the 777 structure can be adapted for such high ZFW's and if it could range would be in the very low 3,000's of NM not making it very useful.

I still don't believe that the A350-900 will have a significantly lighter structure than 777-200ER. I think it's lower fuel burn will come as a benefit of having a smaller frontal area and aero package combined with more efficient engines. From the initial tidbits of information like range and fuel delta relative to 777-200ER, and installed thrust one can estimate that the structural mass will be pretty similar to 72ER. The difficulty for the Boeing to keep up is that the 777 fuselage can not be made any smaller so even if the engine efficiency is increased, without doing anything else it's still about 12% in the hole on drag alone...However, if Boeing can apply the kind of weight reduction to the 777-200ER combined with the bleed enabled engines developed for A350 they may be able to quickly develop an airplane that closely matches A350-900 efficiency without spending the billions that Airbus will. 7t OEW for the -200ER takes the plane's range easily out to 8,500nm and the new engines may be able to reduce fuel burn by 7-8% reducing total fuel burn delta for similar ranges and payloads to the low single digits...very interesting...

Lightening up the LR is the way to go as far as getting a plane out there that satisfies QF. 7t reduced OEW puts the still air range out to 10,000-10,200nm, very nice, and without burning any more fuel. It also makes the 777-200LR more attractive to customers who don't need the extra range/fuel tankage by allowing about 9,500nm or so without the ACT, or increased payloads on the longest sectors 777-200ER now flies. It should be a great boost to sales in the interim as it makes the 777-200LR more efficient than the -200ER on every route it flies...

-widebodyphotog

Starlionblue
Posts: 20950
Joined: Fri Feb 27, 2004 9:54 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting GoCOgo (Reply 78):When was the last time you saw a weatherperson predict a high of 23.5 degrees C? Or when asked weight, responded that you weighed 80.4 kg? People automatically round to the whole, but with many metric units, you need another decimal place to get similar accuracy to US. As is pointed out below, their is a distinction between 75 and 76 F, but they are both 24 C in metric.

 Quoting GoCOgo (Reply 78):Quoting PolymerPlane (Reply 73): Regarding the accuracy, does it really matter for you whether the temperature outside is 75 or 76 F, which can easily be represented as 24 C. For the average Joe, watching the weather, I suppose not. But you can never have too much precision. You can round off extra sig. figs, but you can't get them if you never had them.

How much precision do you need? And besides, if you start saying "you can never have too much precision" you will soon be using fractions of F degrees anyway.

 Quoting Ikramerica (Reply 100): People average between 5' and 6' tall, and being able to break that down into feet and inches makes it relatable. Saying people range from 1.525 to 1.825 meters and having that mean something is a much harder sell...

Metric heights are much more relatable to me since they're what I'm used to. Your argument that feet and inches are more relatable is purely subjective based on your experience.

Imperial/US units are based on traditional measures which were different for different applicatoins. Feet, fathoms, furlongs, pounds, gallons. When you try to go from one to the other, you get messy conversions.

One point of metric is inter-relatability. The ability to have unique and fixed relationships between weight, length, volume, etc, measurements with even numbered conversion factos.

Let me say though, that if only two countries in the world (the US and St. Lucia) used metric and the rest used Imperial/US measures, I would feel inclined to think the minority should change then too.

sunrisevalley
Posts: 5392
Joined: Tue Jul 06, 2004 3:26 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Widebodyphotog (Reply 129):7t OEW for the -200ER takes the plane's range easily out to 8,500nm and the new engines may be able to reduce fuel burn by 7-8%

 Quoting Widebodyphotog (Reply 129): Lightening up the LR is the way to go as far as getting a plane out there that satisfies QF.

My question is what is a realistic time frame for all this? Presumably a new engine is only an option for the 777-200ER ?
Any estimate how long QF would be willing to wait for an enhanced -200LR?

Gemuser
Posts: 5144
Joined: Mon Nov 24, 2003 12:07 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting SunriseValley (Reply 131):Any estimate how long QF would be willing to wait for an enhanced -200LR?

Until a better offer comes along! There is, AFAIK, no other realistic proposal in the works, so Boeing has as long as it takes, as the requirement for SYD/MEL-LHR-SYD/MEL non stop plane is not likely to go away.

Gemuser

sunrisevalley
Posts: 5392
Joined: Tue Jul 06, 2004 3:26 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Gemuser (Reply 132):Until a better offer comes along!

Fair comment. However don't you think the SYD/MEL-DFW/NYC route possibilities should be considered in the overall scheme of things in so far as the -200LR is concerned?

BoomBoom
Posts: 2459
Joined: Fri Nov 04, 2005 2:26 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Lightsaber (Reply 119):Boeing spaces ribs in the plane 20" apart. Last I heard, they'll do the same thing in the 787

I thought the 787 wasn't going to have any ribs since it's a CRRP fuselage.

pygmalion
Posts: 839
Joined: Thu Jun 29, 2006 12:47 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting BoomBoom (Reply 134):Quoting Lightsaber (Reply 119): Boeing spaces ribs in the plane 20" apart. Last I heard, they'll do the same thing in the 787 I thought the 787 wasn't going to have any ribs since it's a CRRP fuselage.

You still have to transfer the floor loads to the monocoque skin somehow... The pax don't suspend themselves from sky hooks. Frames are also what support loads in non circular bodies to keep them from going round when you blow them up... the frames on the 787 are composite but still there

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting SJCRRPAX (Reply 125):Maybe I'm bi-lingual, but It has always been my opinion that any student who couldn't convert from one measurement system to another in his sleep was in the wrong major. Switching units is trivial, and American Units are defined exactly with respect to Metric units. IT has never really mattered to me one way or the other, but I must say a dozen is a very good number. Its divisable by 1,2, 3, 4, 6, and sometimes 8 and 9 (if you can break the cookies up). So for many things a dozen is far better than 10.

lol...I just think you are one big geek....

to be honest, it is a bit trivial, and we are being a bit pedantic...but at the end of the day, the SI is the worldwide accepted standards of measurements.....not saying using some other measurements are wrong however...

 Quoting Dank (Reply 126):I honestly find the SI metric system to be quite beautiful. but it must be in the inner geek in me  .

Join the club..

 Quoting Widebodyphotog (Reply 129):I still don't believe that the A350-900 will have a significantly lighter structure than 777-200ER. I think it's lower fuel burn will come as a benefit of having a smaller frontal area and aero package combined with more efficient engines. From the initial tidbits of information like range and fuel delta relative to 777-200ER, and installed thrust one can estimate that the structural mass will be pretty similar to 72ER. The difficulty for the Boeing to keep up is that the 777 fuselage can not be made any smaller so even if the engine efficiency is increased, without doing anything else it's still about 12% in the hole on drag alone...However, if Boeing can apply the kind of weight reduction to the 777-200ER combined with the bleed enabled engines developed for A350 they may be able to quickly develop an airplane that closely matches A350-900 efficiency without spending the billions that Airbus will. 7t OEW for the -200ER takes the plane's range easily out to 8,500nm and the new engines may be able to reduce fuel burn by 7-8% reducing total fuel burn delta for similar ranges and payloads to the low single digits...very interesting...

regarding the -200ER....for practical purposes..isnt' that what Boeing is going to be doing with the 787-10......? I.e.-challange the A359..

I don't see Boeing challenging the A358/A359 with the -200ER....

it seems as if the -200ER is becoming relegated to "2nd-class" status...I would think all work will now focus on efficiencies on the other 777's -200LR/-200F/-300ER...

however, what I find intersting is how will the 77W engine efficiencies challange/match that of the A350-1000...  ....

baroque
Posts: 12302
Joined: Thu Apr 27, 2006 2:15 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting OzGlobal (Reply 98):No, you Americans use the British system. Sorry to break it to you.

 Quoting Ikramerica (Reply 100):Very true. Same experience for me in my CE degree. NEITHER one is simple, both are convoluted to some degree. Both start with a basic idea and then grow from there: 1 pound of water = 1 pint of water 1 ml of water = 1 g of water metric ads another equivalence 1cc = 1ml But none of that makes it simple, really. Relatability makes things simple.

Mostly US and Imperial measures are similar but the gallon, the ****** gallon. This entry actually oversimplifies the matter.

http://en.wikipedia.org/wiki/Gallon

Current definitions.
* US liquid gallon is 231 inï¿½ (exactly) or 128 fl oz (exactly) or 3.785411784 litres
* US dry gallon is 4.404 884 L
* Imperial gallon is 4.54609 L (exactly). That is approximately 1.201 US gallons.

Older UK definitions.
* The corn gallon, or ï¿½Winchester gallonï¿½, of about 268.8 inï¿½ (4.405 L),
* the wine gallon, or ï¿½Queen Anneï¿½s gallonï¿½, which was 231 inï¿½ (3.79 L), and
* the ale gallon of 282 inï¿½ (4.62 L).

The US basically took what the UK was doing in 1776, and the Brits thought their own system was so awful that in 1824 they changed to use the ale gallon. Well more or less they did, it was actually 10 lbs of distilled water at 30" of Hg and 62degF. But some excise measures were still based on other measures, and apparently some still are to this day - but perhaps the UK drinkers can tell us more about that.

While the US says a pint is a pound all the world round, the UK says a pint of pure water weighs a pound and a quarter.

My children (from Aus) were interviewed at a US school and we were told that they were OK but a little backward in some areas. What would they be, mensuration. Oh, well they dont know much about feet and inches - no metres and so on, pints - litres, till finally an astonished teacher said, well what do they do about quarts!

So this is a plea for the Metric system.

Oh and there is the story in this globalised world of a Ford Cortina driver who blew the welsh plugs on his engine, 100 kms back of the black stump. They found there were three, one was as US standard, one was BS and one metric. Only took about three weeks to get all three.

And possibly even further off topic, but maps made in France used to use Paris as the zero meridian, and some French companies reported lats and longs using that (other) zero meridian on the opposite side of the world. I hope that no longer happens.

On topic. If it so "easy" to get 7 tonnes (a tonny/tonnie is always metric by the by) or tons (could be short long or even intermediate for all I care) off a 777, what have Airbus been doing leaving their overweight 345/6s swanning around without a slimming course?

Starlionblue
Posts: 20950
Joined: Fri Feb 27, 2004 9:54 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Baroque (Reply 137):And possibly even further off topic, but maps made in France used to use Paris as the zero meridian, and some French companies reported lats and longs using that (other) zero meridian on the opposite side of the world. I hope that no longer happens.

Indeed. And the metre was originally one ten millionth of the distance from the Equator to the North Pole along the Paris meridian at sea level.

astuteman
Posts: 7507
Joined: Mon Jan 24, 2005 7:50 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Baroque (Reply 137):On topic. If it so "easy" to get 7 tonnes (a tonny/tonnie is always metric by the by) or tons (could be short long or even intermediate for all I care) off a 777, what have Airbus been doing leaving their overweight 345/6s swanning around without a slimming course?

Ah yes - "potential".

You would have thought that the more overweight the frame, the more potential there was for improvement, but apparently this ignores a basic alphabetical principle...

"B" comes before "A"

Regards

atmx2000
Posts: 4301
Joined: Wed Oct 13, 2004 4:24 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Baroque (Reply 137):On topic. If it so "easy" to get 7 tonnes (a tonny/tonnie is always metric by the by) or tons (could be short long or even intermediate for all I care) off a 777, what have Airbus been doing leaving their overweight 345/6s swanning around without a slimming course?

Perhaps the flaws are so fundamental to the design. The A345 is far more than 7t heavier than the 772LR. The difference between the A345 and A346 is very small, while that between the 772LR and 773ER is much larger, so that the difference between the 773ER and A346 is smaller. And that doesn't even address other problems the quad design, such as the airframes apparently higher drag, reflected in a higher cruise thrust than would simply be expected on the basis of weight, a lower operating speed, and less efficient engines.

astuteman
Posts: 7507
Joined: Mon Jan 24, 2005 7:50 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Atmx2000 (Reply 140):Perhaps the flaws are so fundamental to the design.

Which presumably means a brand new design (like the A350X) should have FAR MORE potential than a tweak of the "flawed" existing design (like the old A350)...........

Regards

Rheinbote
Posts: 1103
Joined: Sun May 21, 2006 9:30 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Lightsaber (Reply 119): Boeing spaces ribs in the plane 20" apart. Last I heard, they'll do the same thing in the 787 (but correct me if I'm wrong).

 Quoting BoomBoom (Reply 134): I thought the 787 wasn't going to have any ribs since it's a CRRP fuselage.

The frames [sic] are spaced 25'' apart.

[Edited 2006-07-20 19:59:41]

widebodyphotog
Posts: 885
Joined: Wed Jun 30, 1999 9:23 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 136):it seems as if the -200ER is becoming relegated to "2nd-class" status...I would think all work will now focus on efficiencies on the other 777's -200LR/-200F/-300ER...

I think in a manner of speaking yes. But the problem is that there are no engines available that could increase the range of 787-10 to 8,500nm or so. The engines for A350 are promising the needed thrust range, 85,000lbt, but will not be available until 2014??? 787-10 will definitely EIS at least a year before that if not two. In the interim a lighter, longer range 777-200ER may be the way to go...

787-10 will be a fine airplane with the available 75,000lbt engines but range will be limited to 7,500-7,700nm initially. 80,000lbt+ allows higher MTOW with an increased mass fraction of fuel for ranges of 8,300-8,600nm...

-widebodyphotog

2wingtips
Posts: 487
Joined: Fri Jul 21, 2006 12:42 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Widebodyphotog (Reply 143):I think in a manner of speaking yes. But the problem is that there are no engines available that could increase the range of 787-10 to 8,500nm or so. The engines for A350 are promising the needed thrust range, 85,000lbt, but will not be available until 2014??? 787-10 will definitely EIS at least a year before that if not two. In the interim a lighter, longer range 777-200ER may be the way to go... 787-10 will be a fine airplane with the available 75,000lbt engines but range will be limited to 7,500-7,700nm initially. 80,000lbt+ allows higher MTOW with an increased mass fraction of fuel for ranges of 8,300-8,600nm...

Are you sure about the timing of the 85klb engines WBP? I thought the A350-900 was going to be first to market in 2012. I assume this will have the 85klb powerplants. With the 787-10 EIS due around the same time and both GE/RR committed to future 787 engine derivatives, couldn't both engine OEMs make bleedless versions suitable for the -10?

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Widebodyphotog (Reply 143):I think in a manner of speaking yes. But the problem is that there are no engines available that could increase the range of 787-10 to 8,500nm or so. The engines for A350 are promising the needed thrust range, 85,000lbt, but will not be available until 2014??? 787-10 will definitely EIS at least a year before that if not two. In the interim a lighter, longer range 777-200ER may be the way to go... 787-10 will be a fine airplane with the available 75,000lbt engines but range will be limited to 7,500-7,700nm initially. 80,000lbt+ allows higher MTOW with an increased mass fraction of fuel for ranges of 8,300-8,600nm...

thanks for the reply..but right now, I assumed that the thrust for the GenX is at "peak" maximum (i.e-might not be technologically feasible to increase thrust for this particular kind of engine)....I'm sure GE (and probably RR) will be able to get some tweaks out of it also to get the increased thrust for the 787-10....also, most carriers (I'm using that sparingly) really don't need the range of a potential 8500nm 787-10...

-and with Boeing, since they tend to be a bit conservative, I could see then eventually getting to the 8000nm range, which I think would satisfy most carriers....maybe not EK...but they are in a world of their own..

widebodyphotog
Posts: 885
Joined: Wed Jun 30, 1999 9:23 am

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Jacobin777 (Reply 145):thanks for the reply..but right now, I assumed that the thrust for the GenX is at "peak" maximum (i.e-might not be technologically feasible to increase thrust for this particular kind of engine)....I'm sure GE (and probably RR) will be able to get some tweaks out of it also to get the increased thrust for the 787-10....also, most carriers (I'm using that sparingly) really don't need the range of a potential 8500nm 787-10... -and with Boeing, since they tend to be a bit conservative, I could see then eventually getting to the 8000nm range, which I think would satisfy most carriers....maybe not EK...but they are in a world of their own..

I can say from working with some of the customers that are interested in 787-10 the request is for more range than the 75Klb engines will allow. 787-10 has more revenue generating space and volume than 777-200ER so in order to use it effectively the airplane has to be able to carry higher commercial payloads over similar distances. Carriers don't need 8,500nm range to fly 8,500nm with passenger only payloads. They need the headroom in order to fly 80,000lb payloads 7,000nm and the 787-10 at this juncture can not do that.

Refining the 777-200ER or -200LR with significant improvements as far as operating weights and incremental engine efficiency meets the interim demand for longer routes that are increasingly flown by 777's. Especially among the operators who do not want to or can not afford to acquire 777-300ER's.

As far as GEnX is concerned, it is at the edge of it's reliable power envelope at 75Klb and the worst part is that climb and cruise thrust can not be increased significantly at all without sacrificing reliability. Rolls has the better mouse trap in that regard and possibly a Trent variant with common architecture with their current offering can be developed for heavier 787-10's.

-widebodyphotog

astuteman
Posts: 7507
Joined: Mon Jan 24, 2005 7:50 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Widebodyphotog (Reply 143):The engines for A350 are promising the needed thrust range, 85,000lbt, but will not be available until 2014???

 Quoting 2wingtips (Reply 144):I thought the A350-900 was going to be first to market in 2012.

Beat me to it. Provided there's no delays WBP, "new" 85k engines should be EIS in 2012 for the A350X-900.

 Quoting Jacobin777 (Reply 136):I don't see Boeing challenging the A358/A359 with the -200ER....

A thought.....
If you make a substantial improvement to an aircraft, you end up giving it a whole heap more capability, and could even move it "up market".
For me, it's entirely possible that improving the 773ER/772LR to this degree, moves their capability so far that it leaves you with (IIRC) 760 000lb MTOW aircraft whose nearest competitor is - Y3, and not the A350X. It will always be a "heavier" (MTOW) aircraft.

However, the 772ER, at (IIRC again) c 660 000lb, if improved, could neatly sit right in the middle of the A350X range (and in-between the 787 and Y3 until such time as it becomes obsolete).

Does that make any sense?

Regards

jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Widebodyphotog (Reply 146):I can say from working with some of the customers that are interested in 787-10 the request is for more range than the 75Klb engines will allow. 787-10 has more revenue generating space and volume than 777-200ER so in order to use it effectively the airplane has to be able to carry higher commercial payloads over similar distances. Carriers don't need 8,500nm range to fly 8,500nm with passenger only payloads. They need the headroom in order to fly 80,000lb payloads 7,000nm and the 787-10 at this juncture can not do that.

Interesting about carriers wanting more range out of the 787-10..is that something which might be holding EK back?

IIRC, Boeing did say........... "According to Boeing, the dash 10's range likely will be similar to that of the 787-8 at 8,000-8,500 nm. The dash 9 can fly 8,600-8,800 nm. with 250 seats."*..however, maybe that didn't include cargo and your comments might seem to reflect it also.....

*-atwonline.com

however..I did stumble upon this...

"Emirates is driving the demand for the version, which would be a 6-m. stretch from the 787-9 with a range of 14,300 km., 500 km. less than the dash 8. It is understood, however, that Emirates wants greater range and Rolls-Royce, which electrically started the first Trent 1000 late last week, is said to have agreed to certify the engine to above 80,000 lb. thrust to meet that demand"**

**-atwonline.com

if RR can deliver what they are stating (and I don't doubt them), then maybe its possible for carriers to order the 787-10 with RR-engines...

 Quoting Widebodyphotog (Reply 146):As far as GEnX is concerned, it is at the edge of it's reliable power envelope at 75Klb and the worst part is that climb and cruise thrust can not be increased significantly at all without sacrificing reliability. Rolls has the better mouse trap in that regard and possibly a Trent variant with common architecture with their current offering can be developed for heavier 787-10's.

ok..so it is in agreement to what I was stating earlier (i.e. "peak" for where the GEnx is at right now)..and as both you and atwonline stated, RR-might be the engine to deliver "the goods" (better mousetrap) for the 787-10

 Quoting Widebodyphotog (Reply 146):Refining the 777-200ER or -200LR with significant improvements as far as operating weights and incremental engine efficiency meets the interim demand for longer routes that are increasingly flown by 777's. Especially among the operators who do not want to or can not afford to acquire 777-300ER's.

ok..I see now where you getting at (regarding improving the -200ER)..it makes sense....incramental improvements should make a good ROI for Boeing and the carriers....

 Quoting Astuteman (Reply 147): However, the 772ER, at (IIRC again) c 660 000lb, if improved, could neatly sit right in the middle of the A350X range (and in-between the 787 and Y3 until such time as it becomes obsolete). Does that make any sense?

yes.....

lightsaber
Moderator
Posts: 23363
Joined: Wed Jan 19, 2005 10:55 pm

### RE: 777-LR To Be Lightened By 7 Tons

 Quoting Widebodyphotog (Reply 129):It should be a great boost to sales in the interim as it makes the 777-200LR more efficient than the -200ER on every route it flies...

Thanks for the info. I always enjoy your posts.

And I didn't know the 767/777 had a different rib pitch... learn something new every day.

A still air range of 10,000nm+ Wow! That opens up a lot of nice routes for Quantas. If SYD-LHR can happen... We'll also see the routes to the USA.

Good night everyone,
Lightsaber

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