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CO787EWR
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787-8/9 Vs 777-200LR

Fri Dec 14, 2007 3:43 am

I know that they are not direct rivals but I was wondering with commencement of EK's IAH-DXB and all the rumors/speculation of CO want to doing the same thing but not having the aircraft available till the 787-8/9. I was wondering how the three would compare to each other in payload, fuel burned, and CASM etc etc.
 
worldtraveler
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RE: 787-8/9 Vs 777-200LR

Fri Dec 14, 2007 3:53 am

excellent question.... I'm not sure we can't answer all of it but it would be good to know.

I'd also like to throw in acquisition cost comparisons as well.

[Edited 2007-12-13 19:53:35]
 
CO787EWR
Topic Author
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RE: 787-8/9 Vs 777-200LR

Sun Dec 16, 2007 4:08 pm

So does anyone have any thoughts?
 
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Stitch
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RE: 787-8/9 Vs 777-200LR

Sun Dec 16, 2007 4:26 pm

MEW:

787-8: 114t
787-9: 119t
777-200LR: 145t

MTOW:

787-8: 220t
787-9: 245t
777-200LR: 347t

Boeing-Spec Passenger Capacity (all three-class at nine-abreast):

787-8: 250
787-9: 290
777-200LR: 301

Maximum range:

787-8: 8200nm
787-9: 8500nm
777-200LR: 9450nm

MZFW: (Thanks to Widebodyphotog)

787-8: 148t
787-9: 165t
777-200LR: 209t

Range at MZFW: (Thanks to Seabosdca)

787-8: 5500nm
787-9: 5700nm
777-200LR: 7400nm

Mission Block Fuel at Maximum Payload (Thanks to Widebodyphotog)

787-8: 68,000l
787-9: 101,000l
777-200LR: 132,000l

Total LD3 Positions:

787-8: 28
787-9: 36
777-200LR: 32

Open LD3 Positions After Bags (1.5 Bags per Passenger / 35 bags per LD3):

787-8: 17
787-9: 23
777-200LR: 19
 
OldAeroGuy
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RE: 787-8/9 Vs 777-200LR

Sun Dec 16, 2007 4:41 pm

About the only other comment to make is that the 772LR has better payload-range (obvious) but the 788/9 will be much cheaper to operate, both on a per trip and a per seat basis.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
tak
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RE: 787-8/9 Vs 777-200LR

Sun Dec 16, 2007 4:45 pm

Stitch, thanks very much for these comparisons. Welcome to my respected users list. You have consistently provided valuable information for all members of anet, thanks for all of your contributions!!!

Ciao, TAK
 
Pihero
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RE: 787-8/9 Vs 777-200LR

Mon Dec 17, 2007 8:53 pm

Stitch,
Some of your figures don't add up :

MTOW - MZFW = Fuel load... right ?

787-8 : 220 T - 148 T = 72 T or 72,000 kg... With fuel density around .8, these 72 T are worth 72,000 / .8 = 90,000 liters, figure that is more coherent with the 787-9's than the 68,000 liters you cite above
On the other hand, the difference between the -8 and the -9 ranges at max payload ( 200Nm ) isn't very flattering to the -9 as it only goes 200Nm farther with an extra 13 T at the expense of 11,000 l of fuel, i.e 8,800 kg. Not exactly good economics...As a matter of comparison, on an equivalent trip length on the same airplane, those extra 13 T necessitate about 1/3 of fuel meaning just under 4,5 T.
Of course, on the other hand, these 8.8 T are coherent with the difference in MTOW (25 T) but it would show the -9 as even less attractive than the -8 on these relatively short distances.

Regards.
Contrail designer
 
tdscanuck
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 5:30 am



Quoting Pihero (Reply 6):

MTOW - MZFW = Fuel load... right ?

Nope. If you load up to MZFW you will hit MTOW before you have full fuel tanks (on most jetliners). As you lower the payload you can increase the fuel until you hit the maximum fuel, which is the farthest you can fly at MTOW. As you lower payload further you can't fit any more fuel so your TOW goes down and your range goes up.

Tom.
 
Pihero
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 11:51 am



Quoting Tdscanuck (Reply 7):
Quoting Pihero (Reply 6):

MTOW - MZFW = Fuel load... right ?

Nope. If you load up to MZFW you will hit MTOW before you have full fuel tanks (on most jetliners).

Did I say anything else ?
And instead of seing a perceived mistake, please check my figures : the fuel loads I quoted are those consistent with a max payload / max takeoff weight.
So the *mission block fuel at maximum payload* quoted above ARE WRONG

I might add that those computations are my dayly bread-and-butter.
Contrail designer
 
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Stitch
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 1:28 pm



Quoting Pihero (Reply 8):
So the *mission block fuel at maximum payload* quoted above ARE WRONG

You'll need to take any dispute with that figure up with Widebodyphotog as he did the calculations behind them. It was the only dataset I could find to try and answer the OP's question.
 
Rheinbote
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 4:10 pm

cough...

[Edited 2007-12-18 08:44:30]
 
Pihero
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 7:55 pm



Quoting Stitch (Reply 9):
You'll need to take any dispute with that figure up with Widebodyphotog as he did the calculations behind them

Don't need to.
He will see it by himself that for one of the data sets, he seems to have used the .8 density factor as a multiplier instead of a divisor.
On the other hand, some of us, being trained in these calculations can pick up an oddness to the ballpark figures we are manipulating, which was the case above. As I told you, these calculations are my bread-and-butter and my skin, too.
I have not questioned the info, I've just pointed at an error, which takes nothing from the author's contribution to this site.
As for us, we should be careful in using raw data without question.

Regards
Contrail designer
 
Rheinbote
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 8:41 pm

Some more up-to-date figures to chew on

MTOW
787-8 219,5t
787-9 244,9t

OEW
787-8 113,6t (242 pass.)
787-9 123,2t (280 pass.)

MZFW
787-8 156,5t
787-9 179,2t

design mission range 3-class LR
787-8 7645nmi (242 pass.)
787-9 8050nmi (280 pass.)

block Fuel per seat, full passenger, 5000nmi
787-8 191kg = 2,57L/100km
787-9 179kg = 2,42L/100km

Max payload range
787-8 5300nmi
787-9 5000nmi
 
widebodyphotog
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 9:44 pm



Quoting Stitch (Reply 3):
787-8: 68,000l

Stich you quoted incorrectly from the data set. The figure in the data table is 87,789L and it should be mentioned that the range point for the fuel figures you cited is 6,000nm. This is not within the MZFW range of all of the listed airplanes.

Quoting Pihero (Reply 11):
He will see it by himself that for one of the data sets, he seems to have used the .8 density factor as a multiplier instead of a divisor.
On the other hand, some of us, being trained in these calculations can pick up an oddness to the ballpark figures we are manipulating, which was the case above. As I told you, these calculations are my bread-and-butter and my skin, too.

It was very observant of you to pick out the incongruity in Stitch's post but before being too critical and presumptive you should have checked the reference information first hand.

Master Mission Data Set



-widebodyphotog
If you know what's really going on then you'll know what to do
 
widebodyphotog
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RE: 787-8/9 Vs 777-200LR

Tue Dec 18, 2007 11:37 pm



Quoting CO787EWR (Thread starter):
I know that they are not direct rivals but I was wondering with commencement of EK's IAH-DXB and all the rumors/speculation of CO want to doing the same thing but not having the aircraft available till the 787-8/9. I was wondering how the three would compare to each other in payload, fuel burned, and CASM etc etc.

This is a great question and since we have a lot of specifics, route, airline, and airplane, we can take a detailed look at how they would compare.

For the 777L, allowing for current seasonal winds, flight times would regularly push nearly 17h in the air DXB-IAH. This would allow a maximum reference ACL of 48t. Currently seating is at 236 and using a reference weight per passenger of 100kg, including distributed ULD tare that leaves a minimum excess payload of 24.4t at 100% passenger load factor. 24t of excess payload is huge for that route and given the space remaining for cargo, way more than typical cargo density would realize in regular operation.

Fuel burn at max ACL for the route would be 131.1t at full load. At an average commercial load of 38t fuel burns would come in at just over 126t. For this route the 777L is capable of moving the largest commercial loads the distance in both directions, year round, no problem.

For the 787's however we run into some payload issues...

An EK spec 787-9 would seat 210-220 with the same economy, first and business class seats as the 777, just with 9, 5, and 6 abreast respectively. Being a faster airplane it would cut the flight time by 10 mins over the 777L, but maximum reference ACL drops to a paltry 22.5t, nothing really. This would just cover the passenger only load for EK and allow no appreciable cargo load.

Fuel burns for the 787-9 would be 91.2t, 38% less than the 777L, but again the allowable payload in the winter winds drops excess and contingency payload below what is useful IMO.

An EK spec 787-8 would seat 180-190, but DXB-IAH in the winter time would have to leave several seats vacant as maximum reference payloads would come in at a disappointing 16.6t. Not enough to even be considered practical. Fuel burn however is a thrifty 79.7t.

For my money its not even a choice really when it comes down to it EK had to go for the 777L. It is absolutely a freight train in the sky, allowing very high commercial loads over very long distances. It's the only airplane that can do what it can do and most likely will be for some time to come. The new 787's are great but as heavy haulers over ULH ranges they fall short of meeting the commercial realities of ULH operation. They will be absolutely fabulous planes for routes that need effective air ranges of 5-6,500nm, but beyond that ACL becomes a limiting factor.



-widebodyphotog
If you know what's really going on then you'll know what to do
 
Pihero
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RE: 787-8/9 Vs 777-200LR

Wed Dec 19, 2007 1:38 am



Quoting Widebodyphotog (Reply 13):
but before being too critical and presumptive you should have checked the reference information first hand.

Sorry, no reference but your name was given above.
I would have checked, had I had one.
Plus read that my post : it was addressed to Stitch, asking him to check his figures before someone jump to my throat, something I have never liked a lot, hence my reaction.

Regards
Contrail designer
 
User avatar
Stitch
Posts: 27542
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RE: 787-8/9 Vs 777-200LR

Wed Dec 19, 2007 4:14 pm



Quoting Widebodyphotog (Reply 13):
Stich you quoted incorrectly from the data set. The figure in the data table is 87,789L and it should be mentioned that the range point for the fuel figures you cited is 6,000nm. This is not within the MZFW range of all of the listed airplanes.

My apologies for not paying proper attention when looking up the data.

Quoting Pihero (Reply 15):
Plus read that my post : it was addressed to Stitch, asking him to check his figures before someone jump to my throat, something I have never liked a lot, hence my reaction.

And my apologies to you, as well. It was not my intent to jump down your throat, just to note that while I posted the data (albeit some of it incorrectly), it was not my personal data so I was not in a position to correct it, myself.

Quoting Widebodyphotog (Reply 14):
This is a great question and since we have a lot of specifics, route, airline, and airplane, we can take a detailed look at how they would compare.

And thank you for this. I have added it to my data collection for future reference (and I promise to be more astute when doing so).
 
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jetlife2
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RE: 787-8/9 Vs 777-200LR

Wed Dec 19, 2007 11:32 pm



Quoting Widebodyphotog (Reply 14):
For my money its not even a choice really when it comes down to it EK had to go for the 777L. It is absolutely a freight train in the sky, allowing very high commercial loads over very long distances.

Hear, hear! What a machine!

And the 200LR is not even a pure freighter! Imagine the 777F on the same route...

 Smile
My views are not necessarily the views of the GE Company
 
surfpunk
Posts: 262
Joined: Tue Sep 25, 2007 2:20 pm

RE: 787-8/9 Vs 777-200LR

Thu Dec 20, 2007 2:54 am

Somewhat related question (n00b-style):

How does one compute Range at MZFW? Particularly since, at zero fuel weight, range = 0 nm.

This is not meant to be a snarky comment, I'm just genuinely curious.
 
tdscanuck
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Joined: Wed Jan 11, 2006 7:25 am

RE: 787-8/9 Vs 777-200LR

Thu Dec 20, 2007 3:55 am



Quoting Surfpunk (Reply 18):

How does one compute Range at MZFW? Particularly since, at zero fuel weight, range = 0 nm.

I'm assuming you mean maximum range at MZFW.

Easy method: find the payload-range chart for the aircraft of interest and find the right-most end of the MZFW line.

Hard method: determine fuel load based on MTOW-MZFW and apply the Brueget range equation.

Best method (if you have access to the data and hardware): program the flight into a Flight Management Computer and see what it says.

Tom.
 
yul332LX
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RE: 787-8/9 Vs 777-200LR

Sun Dec 23, 2007 10:47 pm



Quoting Widebodyphotog (Reply 13):
It was very observant of you to pick out the incongruity in Stitch's post but before being too critical and presumptive you should have checked the reference information first hand.

Master Mission Data Set

interesting chart, Thanks Widebody.
E volavo, volavo felice più in alto del sole, e ancora più su mentre il mondo pian piano spariva lontano laggiù ...
 
iwok
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RE: 787-8/9 Vs 777-200LR

Mon Dec 24, 2007 8:06 am



Quoting Surfpunk (Reply 18):
Somewhat related question (n00b-style):

How does one compute Range at MZFW? Particularly since, at zero fuel weight, range = 0 nm.

This is not meant to be a snarky comment, I'm just genuinely curious.

So here's my layman's understanding.

1. Fill up the plane with passengers and cargo until you have the maximum structural payload on board.
2. Add fuel to the tanks till you reach MTOW.
3. See how far you can fly.

iwok
 
Rheinbote
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RE: 787-8/9 Vs 777-200LR

Mon Dec 24, 2007 1:58 pm

I think the technical term is "Maximum Payload Range"

Merry Christmas / Gesegnete Weihnachten  santahat 
 
surfpunk
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RE: 787-8/9 Vs 777-200LR

Wed Dec 26, 2007 3:28 pm



Quoting Iwok (Reply 21):
So here's my layman's understanding.

1. Fill up the plane with passengers and cargo until you have the maximum structural payload on board.
2. Add fuel to the tanks till you reach MTOW.
3. See how far you can fly.

iwok

That makes sense. Thanks.

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