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AviationWeek - 787 Better Than Expected Fuel Burn  
User currently offlinepygmalion From United States of America, joined Jun 2006, 963 posts, RR: 38
Posted (1 year 9 months 3 weeks 6 days 5 hours ago) and read 38926 times:

Per AV Week article from June 25, 2012, "The first two operators of the Boeing 787-8 are seeing better-than-anticipated fuel burn, despite prior expectations of below-par performance as a result of data from predelivery flight tests.

The numbers, though based on early experience with a relatively small fleet on a variety of routes, are surprisingly positive given the early configuration of the airframes and engines. The operators have not yet incorporated all the planned weight and fuel burn improvements of follow-on production versions."

See full article at

http://www.aviationweek.com/awin/Art...e-xml/awx_06_25_2012_p0-470831.xml

200 replies: All unread, showing first 25:
 
User currently offlinesweair From Sweden, joined Nov 2011, 1806 posts, RR: 0
Reply 1, posted (1 year 9 months 3 weeks 6 days 5 hours ago) and read 38824 times:

Some good news at last, I wonder how much those wings have helped, they are really state of the art. Anyway congrats to the Boeing folks on this page!   

User currently offlineneutronstar73 From United States of America, joined Mar 2011, 427 posts, RR: 0
Reply 2, posted (1 year 9 months 3 weeks 6 days 3 hours ago) and read 38024 times:

That is great news. I hope Boeing keeps it up.

And it appears that this is not just "rosy Beoing PR fluff", as some posters have been quick to point out. According to the article the GEnX is doing exceptionally well!


User currently onlinemham001 From United States of America, joined Feb 2005, 3389 posts, RR: 2
Reply 3, posted (1 year 9 months 3 weeks 6 days 3 hours ago) and read 37948 times:

Where are the people (person?) continuing to claim those numbers are nothing more than PR fluff and lies, perpetrated from the highest echelons of Japans' two largest airlines?

User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 4, posted (1 year 9 months 3 weeks 6 days 3 hours ago) and read 37908 times:
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The article quotes NH saying that on intra-Japan missions the 787's fuel burn savings are between 15 and 20 percent, so it looks like even on very short runs, the 787 is quite fuel-efficient just as it is on medium and long-haul runs.

User currently offlineKDAYflyer From United States of America, joined Jun 2012, 155 posts, RR: 0
Reply 5, posted (1 year 9 months 3 weeks 6 days 2 hours ago) and read 37764 times:

Quoting mham001 (Reply 3):
Where are the people (person?) continuing to claim those numbers are nothing more than PR fluff and lies, perpetrated from the highest echelons of Japans' two largest airlines?

Better yet, where are all the "the 787 is doomed because it is so overweight" neighsayers? Looks like Boeing got it right after all.   


User currently onlineseabosdca From United States of America, joined Sep 2007, 5105 posts, RR: 4
Reply 6, posted (1 year 9 months 3 weeks 6 days 2 hours ago) and read 37621 times:

How do you even determine fuel-burn numbers for a ghost plane? NH must be making stuff up.      


Most gorgeous aircraft: Tu-204-300, 757-200, A330-200, 777-200LR, 787-8
User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 7, posted (1 year 9 months 3 weeks 6 days 2 hours ago) and read 37491 times:

Quoting Stitch (Reply 4):
The article quotes NH saying that on intra-Japan missions the 787's fuel burn savings are between 15 and 20 percent

Wouldn't this be an indication that on the longer sectors it is doing even better than 15-20% ?


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 8, posted (1 year 9 months 3 weeks 6 days 2 hours ago) and read 37458 times:
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Quoting phxa340 (Reply 7):
Wouldn't this be an indication that on the longer sectors it is doing even better than 15-20%?

The CEO of NH stated that for "international travel", fuel burn was ~22% lower, though there was some disagreement on that figure based on the belief that missions to China, being shorter, would see lower fuel savings as a percentage than missions to Germany.

With NH seeing fuel savings as a percentage upwards of 20% for missions within Japan, and even higher for missions outside of Japan, that implies that whatever the stage length, the 787-8 is a pretty darned efficient airframe.

And it will only get more so.


User currently offlineNYC777 From United States of America, joined Jun 2004, 5669 posts, RR: 48
Reply 9, posted (1 year 9 months 3 weeks 6 days 2 hours ago) and read 37316 times:

Yeah a few people saw this coming too

http://www.strategicaeroresearch.com...2/05/04/787-to-make-a330-obsolete/



That which does not kill me makes me stronger.
User currently offlineNYC777 From United States of America, joined Jun 2004, 5669 posts, RR: 48
Reply 10, posted (1 year 9 months 3 weeks 6 days 1 hour ago) and read 37229 times:

Wait till they take more weight out of the airplane and the engines have more improvments by the end of 2013 and Boeing would have trully set the bar at a high level. Airbus does have its work cut out for it and it'll be interesting to see if the A350 can match the 787 on the overall operating costs.


That which does not kill me makes me stronger.
User currently offlineN14AZ From Germany, joined Feb 2007, 2607 posts, RR: 25
Reply 11, posted (1 year 9 months 3 weeks 6 days 1 hour ago) and read 37211 times:

Waow, as soon as the production is running on a higher level I think we will see a new wave of orders.

[Edited 2012-06-26 11:38:56]

User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 12, posted (1 year 9 months 3 weeks 6 days 1 hour ago) and read 37012 times:
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Quoting N14AZ (Reply 11):
Waow, as soon as the production is running on a higher level I think we will see a new wave of orders.

Yes, by the end of the year we should have in-service data from a half-dozen or more operators and Boeing should be (    ) assembling five new airframes a month as well as working through the backlog of airframes parked at PAE. All of which together should hopefully get 787 orders trending into the black again.


User currently offlineBMI727 From United States of America, joined Feb 2009, 15474 posts, RR: 26
Reply 13, posted (1 year 9 months 3 weeks 6 days 1 hour ago) and read 36934 times:

Quoting NYC777 (Reply 9):
Yeah a few people saw this coming too

I thought that this was pretty well established that the 787 was better than expected aerodynamically, hence no new wing for the 787-9. Anyone who thought otherwise probably just wasn't paying attention.



Why do Aerospace Engineering students have to turn things in on time?
User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 14, posted (1 year 9 months 3 weeks 6 days 1 hour ago) and read 36828 times:
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Quoting BMI727 (Reply 13):
I thought that this was pretty well established that the 787 was better than expected aerodynamically, hence no new wing for the 787-9.

If Boeing had gone with the 63m span for the 787-9, they noted aerodynamic performance would be even better, but the extra weight of that span would effectively negate it, so it was a wash either way and therefore commonality benefits were more important.


User currently offlinelightsaber From United States of America, joined Jan 2005, 12420 posts, RR: 100
Reply 15, posted (1 year 9 months 3 weeks 6 days ago) and read 36776 times:
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Quoting pygmalion (Thread starter):
See full article at

Requires a log in.  
Quoting KDAYflyer (Reply 5):
Better yet, where are all the "the 787 is doomed because it is so overweight" neighsayers?

The 787 is still mission limited due to the overweight. That is a lot less catering and fuel that can be carried at a given payload:
http://www.flightglobal.com/blogs/fl...xcess-weight-keeps-anas-early.html

But the parts for acceptable weight 788s are now arriving.

LN63 is the first 788 without rework (saves time and weight)!
http://www.aspireaviation.com/2012/0...nts-along-with-production-ramp-up/

Many are waiting for LN90+ which should meet empty weight promise (and have a higher MTOW):
http://airsoc.com/articles/view/id/4...ficient-than-a330-new-report-finds

"Utilising US Department of Transportation (DOT) Form 41 data, the cost per seat mile of a 787-8 is 10.4% lower than a Boeing 767-300ER (extended range) equipped with winglets whereas an A330-200 HGW’s is 5.8% lower than the 767-300ER on a 2,100 nautical miles (nm) mission. In cost per aircraft mile, the 787-8′s figure is 5.17% lower than a winglet-equipped 767-300ER whereas an A330-200 HGW’s is 7.13% higher than the 767-300ER aircraft."

If the Form 41 data is accurate, than we already have a plane cheaper to fly than a 763ER with far more range and a bit more payload.

Quoting Stitch (Reply 12):
Yes, by the end of the year we should have in-service data from a half-dozen or more operators and Boeing should be (    ) assembling five new airframes a month as well as working through the backlog of airframes parked at PAE.

Let's see, UA pax service in Q4 per post 205:
787 Production Thread Part 4 (by LipeGIG May 30 2012 in Civil Aviation)#1

QR is due soon (July?), with service to follow in a few months.
LAN receives in August (service in?).
By September Ethiopian too (some sources early as July, but I'm not sure).

And eventually we'll hear about in service data from AI.   


Lightsaber



I've posted how many times?!?
User currently offlineN14AZ From Germany, joined Feb 2007, 2607 posts, RR: 25
Reply 16, posted (1 year 9 months 3 weeks 6 days ago) and read 36655 times:

Quoting lightsaber (Reply 15):
And eventually we'll hear about in service data from AI

Don't expect too much from them. Most probably they will complain about the fact that their financial situation is due to the high level of CFRP used on the 787...  Wink Sorry to all Indian a.netters - couldn't resist ...

[Edited 2012-06-26 12:47:31]

User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 17, posted (1 year 9 months 3 weeks 6 days ago) and read 36266 times:
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Quoting lightsaber (Reply 15):
Requires a log in.

Google News is your friend.  


User currently offlineNYC777 From United States of America, joined Jun 2004, 5669 posts, RR: 48
Reply 18, posted (1 year 9 months 3 weeks 6 days ago) and read 36218 times:

Quoting lightsaber (Reply 15):
LN63 is the first 788 without rework (saves time and weight)!

No it's LN66 not 63.



That which does not kill me makes me stronger.
User currently offlineabnormal From UK - England, joined Aug 2007, 81 posts, RR: 0
Reply 19, posted (1 year 9 months 3 weeks 6 days ago) and read 36166 times:

Not to burst the bubble here but, thanks to the delay in certifying the aircraft I expect, come 2014 when that aircraft needs to be FANS 2 compliant for flight in the EU above FL285, it won't be. All 787 flying after that date will be below RVSM airspace until the FANS 2 retrofit is available.

As Boeing's target for FANS 2 certification was the first 787-9, and they have been denied an exemption for any non FANS 2 -8s aircraft after Jan 01 2014, anybody planning on operating a -8 into EU airspace is going to pretty annoyed until the retrofit is available.


User currently offlinefpetrutiu From United States of America, joined Aug 2007, 866 posts, RR: 0
Reply 20, posted (1 year 9 months 3 weeks 6 days ago) and read 35763 times:

Quoting abnormal (Reply 19):
As Boeing's target for FANS 2 certification was the first 787-9, and they have been denied an exemption for any non FANS 2 -8s aircraft after Jan 01 2014, anybody planning on operating a -8 into EU airspace is going to pretty annoyed until the retrofit is available.

Source? NH is operating HND-FRA without issues. A380's are FANS 1 pending retrofit like the B787-8.


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 21, posted (1 year 9 months 3 weeks 5 days 23 hours ago) and read 35717 times:

Quoting abnormal (Reply 19):
Not to burst the bubble here but, thanks to the delay in certifying the aircraft I expect, come 2014 when that aircraft needs to be FANS 2 compliant for flight in the EU above FL285, it won't be.

What's involved in the FANS 2 retrofit and why don't we think it will be ready by 2014? The chance that it's not just a software change is pretty small.

Tom.


User currently offlineikramerica From United States of America, joined May 2005, 21416 posts, RR: 60
Reply 22, posted (1 year 9 months 3 weeks 5 days 23 hours ago) and read 35623 times:

Quoting N14AZ (Reply 11):
Waow, as soon as the production is running on a higher level I think we will see a new wave of orders.

That's likely. The 3+ years of delay lead to 3+ years of no net orders (net loss) due to there being little point in ordering. If your timeframe is 6 years, why order something that isn't available for 10?



Of all the things to worry about... the Wookie has no pants.
User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 23, posted (1 year 9 months 3 weeks 5 days 23 hours ago) and read 34809 times:

Quoting mham001 (Reply 3):
Where are the people (person?) continuing to claim those numbers are nothing more than PR fluff and lies, perpetrated from the highest echelons of Japans' two largest airlines?

I will happily put my hand up here   

As we discussed lat week when these numbers were released by ANA, it was reported in the English press that this was 20% lower trip fuel. The actual Japanese version of the ANA press release states it was on a per seat basis.



It would also appear that the comparison was done between two configurations which had the same difference in seat capacity, i.e. the 787 with around 265 seats, and the 763 with around 215 seats.

In short, the numbers did not present anything in my view that was a convincing improvement over the 763.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineDelimit From United States of America, joined Jan 2009, 1486 posts, RR: 2
Reply 24, posted (1 year 9 months 3 weeks 5 days 22 hours ago) and read 34932 times:

That would either be a non-story or worse, actively bad PR. None of the press makes sense it that were the case.

User currently offlinelightsaber From United States of America, joined Jan 2005, 12420 posts, RR: 100
Reply 25, posted (1 year 9 months 3 weeks 5 days 22 hours ago) and read 35069 times:
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What strikes me is that by year end 2013 there won't be enough 787s in the global fleet to truly impact route pricing.   That will take until the end of 2015 or even 2016. Oh well, more time for a.net debates. (It will take 300+.)

I'm patient.  
Quoting Stitch (Reply 17):
Google News is your friend.

Yes it is. Thank you.

Quoting NYC777 (Reply 18):
No it's LN66 not 63.

You're right, I look here and I see that quite a few of the low 60's are in rework:
http://nyc787.blogspot.com/

I'm off by so much.   What matters is soon they will head out the door into the fleet with only a month or so delay.    Soon as in July delivery (expected)!

In fact, checking the above link shows that LN66-68 are undergoing prep for final delivery. Interesting to see that the LN66+ will quickly ramp to 5 frames/month until late 2013 when they ramp up to 10 frames/month.

Quoting zeke (Reply 23):
The actual Japanese version of the ANA press release states it was on a per seat basis.

That makes more sense. But still, that has the 788 at a lower per trip cost than the 763ER.   

Lightsaber



I've posted how many times?!?
User currently offlineLAXDESI From United States of America, joined May 2005, 5086 posts, RR: 48
Reply 26, posted (1 year 9 months 3 weeks 5 days 21 hours ago) and read 34513 times:

Quoting lightsaber (Reply 15):
Many are waiting for LN90+ which should meet empty weight promise (and have a higher MTOW):
http://airsoc.com/articles/view/id/4...ficient-than-a330-new-report-finds

"Utilising US Department of Transportation (DOT) Form 41 data, the cost per seat mile of a 787-8 is 10.4% lower than a Boeing 767-300ER (extended range) equipped with winglets whereas an A330-200 HGW’s is 5.8% lower than the 767-300ER on a 2,100 nautical miles (nm) mission. In cost per aircraft mile, the 787-8′s figure is 5.17% lower than a winglet-equipped 767-300ER whereas an A330-200 HGW’s is 7.13% higher than the 767-300ER aircraft."

Good find, and thanks for sharing.

Based on the above, early 788s on a short mission have nearly a 5% seat fuel burn advantage over A332HGW. One would expect a mature B788 to increase this gap to 8-9%. I expect a mature B788 to have 16-18% seat fuel burn advantage over A332 on long missions.

A332 may still be an attractive aircraft, at the right price, for short/medium haul routes.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 27, posted (1 year 9 months 3 weeks 5 days 21 hours ago) and read 34927 times:

Quoting zeke (Reply 23):
t was reported in the English press that this was 20% lower trip fuel.

Incorrect. The Aviationweek article does not say trip fuel burn. What news articles are you referring to. Can you link any?

http://www.aviationweek.com/Article....d_06_26_2012_p01-01-470896.xml&p=1

Quoting zeke (Reply 23):
The actual Japanese version of the ANA press release states it was on a per seat basis.

CASM is an important metric. If that's not a convincing metric for you....you are free to raise your hand and state it's not an important metric in your mind.

Quoting zeke (Reply 25):
The 787 has around a 66,000 lb higher OEW than the 767, one would not expect it to have operational advantages over all routes.

Even if true, it does not change the advantages it has or change the numbers. But your thinking, that because the 787 has a heavier OEW, that it is natural for it to be 20% more efficient per seat, is overly simplistic.

For instance, the A330 - 300 is also heavier than the 767-300 by even more than the 787-8, by 76,000lbs, that's a 38% heavier OEW over the 767-300 - yet is nowhere near 38% or even 20% more efficient than the 767-300 winglets per seat. More like 8%. That proves the 787 -8 has far better CASM than the A330-300 and 767-300 winglets. Far better.

If it were all about weight, the A330-300 would top the 787-8 in CASM, but it doesn't, despite being heavier. So it's not all about OEW.


User currently onlineViscount724 From Switzerland, joined Oct 2006, 24075 posts, RR: 22
Reply 28, posted (1 year 9 months 3 weeks 5 days 21 hours ago) and read 34632 times:

Quoting Stitch (Reply 17):
Quoting lightsaber (Reply 15):
Requires a log in.

Google News is your friend.

But some people may want to read the actual Aviation Week article which they can't access if they're not a paid subscriber, or am I missing your point?


User currently offlineflylku From United States of America, joined Apr 2006, 787 posts, RR: 0
Reply 29, posted (1 year 9 months 3 weeks 5 days 21 hours ago) and read 34367 times:

Quoting N14AZ (Reply 11):
Waow, as soon as the production is running on a higher level I think we will see a new wave of orders.

Agreed if this is validated over a slightly larger data set.

What is the earliest delivery slot available.

Ironically this can help Airbus as well. An airline that wants to remain competitive needs the next generation technology as soon as possible. Can't get it soon enough from Boeing? Buy it from Airbus. Of course it works both ways.



...are we there yet?
User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 30, posted (1 year 9 months 3 weeks 5 days 21 hours ago) and read 34174 times:
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Quoting Viscount724 (Reply 33):
But some people may want to read the actual Aviation Week article which they can't access if they're not a paid subscriber, or am I missing your point?

Google News bypasses the Aviation Week gatekeeper and lets you directly read the article on their site.


User currently onlineViscount724 From Switzerland, joined Oct 2006, 24075 posts, RR: 22
Reply 31, posted (1 year 9 months 3 weeks 5 days 21 hours ago) and read 33980 times:

Quoting Stitch (Reply 35):
Quoting Viscount724 (Reply 33):
But some people may want to read the actual Aviation Week article which they can't access if they're not a paid subscriber, or am I missing your point?

Google News bypasses the Aviation Week gatekeeper and lets you directly read the article on their site.

Do the magazines complain about Google hacking into their subscription-only publications, or have they agreed to let them? Seems to undermine the value of a subscription-only site.


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 32, posted (1 year 9 months 3 weeks 5 days 20 hours ago) and read 33220 times:
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Quoting tommytoyz (Reply 32):
The Aviationweek article does not say trip fuel burn. What news articles are you referring to. Can you link any?

Earlier statements on fuel savings by NH CEO Shinichiro Ito referred to "per trip" and as such, there was a heavy debate about it in Rave Reviews For Boeings 787 (by Navion Jun 14 2012 in Civil Aviation).


User currently offlineglideslope From United States of America, joined May 2004, 1594 posts, RR: 0
Reply 33, posted (1 year 9 months 3 weeks 5 days 18 hours ago) and read 31512 times:

Quoting abnormal (Reply 19):
Not to burst the bubble here but, thanks to the delay in certifying the aircraft I expect, come 2014 when that aircraft needs to be FANS 2 compliant for flight in the EU above FL285, it won't be. All 787 flying after that date will be below RVSM airspace until the FANS 2 retrofit is available.

As Boeing's target for FANS 2 certification was the first 787-9, and they have been denied an exemption for any non FANS 2 -8s aircraft after Jan 01 2014, anybody planning on operating a -8 into EU airspace is going to pretty annoyed until the retrofit is available.

You really think there will still be an EU in 2014? Most of my colleagues do not.

The 350 has it's work cut out for it.

[Edited 2012-06-26 18:56:08]


To know your Enemy, you must become your Enemy.” Sun Tzu
User currently offlineflightsimer From United States of America, joined Aug 2009, 513 posts, RR: 1
Reply 34, posted (1 year 9 months 3 weeks 5 days 18 hours ago) and read 31399 times:

Quoting glideslope (Reply 40):

Well there is that... But that's a convo for a completely different thread...



Commercial Pilot- SEL, MEL, Instrument
User currently offlinelightsaber From United States of America, joined Jan 2005, 12420 posts, RR: 100
Reply 35, posted (1 year 9 months 3 weeks 5 days 17 hours ago) and read 30902 times:
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Quoting LAXDESI (Reply 31):
A332 may still be an attractive aircraft, at the right price, for short/medium haul routes.

But for those missions, the A333 is an *even* more attractive aircraft. In particular if it gains winglets.   

The numbers are in the 787s favor. It just shows that Airbus should have removed the two tons of weight from the A330 earlier and put on the winglets earlier.   In that alternate universe we already have CMC turbine blades and beer and wine now produce negative calories.   


Lightsaber



I've posted how many times?!?
User currently onlineseabosdca From United States of America, joined Sep 2007, 5105 posts, RR: 4
Reply 36, posted (1 year 9 months 3 weeks 5 days 17 hours ago) and read 30177 times:

Quoting lightsaber (Reply 42):
In that alternate universe we already have CMC turbine blades and beer and wine now produce negative calories.

I think you need to stop mucking around with your silly aircraft engines and get to work on the truly important problem listed above.   



Most gorgeous aircraft: Tu-204-300, 757-200, A330-200, 777-200LR, 787-8
User currently offlineSSTsomeday From Canada, joined Oct 2006, 1276 posts, RR: 1
Reply 37, posted (1 year 9 months 3 weeks 5 days 14 hours ago) and read 28285 times:

Quoting Stitch (Reply 8):
the 787-8 is a pretty darned efficient airframe.

And it will only get more so.

Off topic but.... Speaking of new Boeings, I'm looking forward to the 747-8 numbers....

Maybe they got it right twice.  crossfingers 

[Edited 2012-06-26 23:06:00]


I come in peace
User currently offlineautothrust From Switzerland, joined Jun 2006, 1545 posts, RR: 9
Reply 38, posted (1 year 9 months 3 weeks 5 days 13 hours ago) and read 27939 times:

Quoting NYC777 (Reply 9):
Yeah a few people saw this coming too

http://www.strategicaeroresearch.com...lete/

I don't think it's true the 787 being over 20% more efficient over the A330.   
This figure is on comparison to the 767 IIRC.
I also don't think the 787 will be the A330 killer like the 777 to the A340. The A330 is still a very efficient and modern platform and doesn't suffer from two engines more like the A340 did.

For some airlines it will still be the better choice.

[Edited 2012-06-26 23:47:26]


“Faliure is not an option.”
User currently offlineBurkhard From Germany, joined Nov 2006, 4360 posts, RR: 2
Reply 39, posted (1 year 9 months 3 weeks 5 days 13 hours ago) and read 27560 times:

Congrats to have the 788 fuel burn better than expected. End good all good...
Since the engines of ANA and JAL are different, it seems both Trent1000 and GENX 1B perform well. This gives rise to hope that the 748I and the A350 both will perform very well too.


User currently offlineUALWN From Andorra, joined Jun 2009, 2654 posts, RR: 2
Reply 40, posted (1 year 9 months 3 weeks 5 days 10 hours ago) and read 25748 times:

Quoting glideslope (Reply 40):
You really think there will still be an EU in 2014? Most of my colleagues do not.

I'd suggest a change of colleagues.



AT7/111/146/Avro/CRJ/CR9/EMB/ERJ/E75/F50/100/L15/DC9/D10/M8X/717/727/737/747/757/767/777/AB6/310/319/320/321/330/340/380
User currently offlineN14AZ From Germany, joined Feb 2007, 2607 posts, RR: 25
Reply 41, posted (1 year 9 months 3 weeks 5 days 10 hours ago) and read 25528 times:

I really don’t understand why this thread became so emotional and hostile with snippy comments about Airbus, EADS and EU.

One member is raising questions about how the improvement rate has been calculated, which is acceptable in my opinion. To be honest, if it’s correct what he is claiming than I really would like to know it – independent on where this aircraft has been manufactured. Otherwise, what’s the point discussing this article?


User currently offlineCerecl From Australia, joined Jul 2008, 706 posts, RR: 0
Reply 42, posted (1 year 9 months 3 weeks 5 days 10 hours ago) and read 25397 times:

I have suggested closing of this thread since there was no new information from the existing thread. Instead, but perhaps not surprisingly, the thread has degenerated into personal attack.

User currently offlineEPA001 From Netherlands, joined Sep 2006, 4593 posts, RR: 38
Reply 43, posted (1 year 9 months 3 weeks 5 days 10 hours ago) and read 25230 times:
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Quoting Cerecl (Reply 52):

I have suggested closing of this thread

I guess I agree with you on this suggestion.


User currently offlinesweair From Sweden, joined Nov 2011, 1806 posts, RR: 0
Reply 44, posted (1 year 9 months 3 weeks 5 days 10 hours ago) and read 25125 times:

Don't lock a thread, take the comments that are bad out of it.

Now back to the subject, if both ANA and JAL say so I believe it. It seems the 787 will be a very good airplane, when mature later on it will be hard to beat  


User currently offlineSEPilot From United States of America, joined Dec 2006, 6680 posts, RR: 46
Reply 45, posted (1 year 9 months 3 weeks 5 days 10 hours ago) and read 25129 times:

It seems that most new aircraft recently have performed better in service than expected-the 787, the 748, the A380, and the 77W/L. The exception seems to be the A345/346; IIRC the initial ones were disappointing. What I do not recall is whether the other planes performed better than expected after flight testing or whether the flight testing accurately predicted the actual performance. It seems that both the 787 and 748 are doing better than Boeing had led the customers to expect.


The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlinesweair From Sweden, joined Nov 2011, 1806 posts, RR: 0
Reply 46, posted (1 year 9 months 3 weeks 5 days 9 hours ago) and read 24997 times:

Or media report overly negative to create a spin?

User currently offlineSEPilot From United States of America, joined Dec 2006, 6680 posts, RR: 46
Reply 47, posted (1 year 9 months 3 weeks 5 days 9 hours ago) and read 24495 times:

Quoting Flighty (Reply 56):

I agree with you that the 763ER winglet, so far, represents unparalleled low trip cost, until proven otherwise. People can say that's irrelevant, blah blah, but it's not.

But a Gulfstream G650 would have much lower trip cost. What does that prove?   



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 48, posted (1 year 9 months 3 weeks 5 days 9 hours ago) and read 24478 times:

To inject a little honest-to-goodness data into the thread, I went and looked at the long range cruise fuel burn numbers provided in the FCOM Performance Inflight section for the 767-300 and the 787-8. These are typically conservative because they have to work for worst-case engine degradation.

At equal weight (420,000 lbs), a 787-8RR burns 18% less fuel per hour at optimum altitude than a 767-300ER.

But, at Zeke correctly points out, the 787-8 weights more so, with equal payload, the gross weight will be more. If we credit the 787-8 40,000 lbs and take it up to 460,000 lbs for approximately equal payload, the 787-8 still burns 10% less fuel per hour.

Even at maximum weight (540,000 lbs) the 787-8 is only burning 10% more per hour but, at that weight, it's got far more range (or an extra 80,000 lbs of payload).

Since the 787-8 and 767-300 cruise at about the same speeds, the per hour fuel burn is directly equivalent to the per trip fuel burn.

Conclusion: based on *conservative* and certified data provided to all operators, it's entirely possible for the 787-8 to have double digit % *trip fuel* burn advantage over the 767-300, let alone per seat fuel burn.

Tom.


User currently offlinepacksonflight From Iceland, joined Jan 2010, 365 posts, RR: 0
Reply 49, posted (1 year 9 months 3 weeks 5 days 8 hours ago) and read 24216 times:

Why is the 787 compared to the 767 at all?

It should be compared to the original goals and the promises made by Boeing. Anyway we can hold our breath... the AWST article says that Boeing will be commenting on the 787 fuel burn at Farnborough.


User currently offlineDelimit From United States of America, joined Jan 2009, 1486 posts, RR: 2
Reply 50, posted (1 year 9 months 3 weeks 5 days 8 hours ago) and read 24081 times:

Because the original goals set by Boeing used the 767.  

It was originally Boeing's claim that the 787 would be 20% more efficient than the 767.


User currently offlineSEPilot From United States of America, joined Dec 2006, 6680 posts, RR: 46
Reply 51, posted (1 year 9 months 3 weeks 5 days 8 hours ago) and read 23993 times:

Quoting Delimit (Reply 50):
It was originally Boeing's claim that the 787 would be 20% more efficient than the 767

And it appears that this goal has been met, even by the very first "grossly overweight" birds. It bodes very well for future production, which will only get better.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineastuteman From United Kingdom, joined Jan 2005, 9836 posts, RR: 96
Reply 52, posted (1 year 9 months 3 weeks 5 days 8 hours ago) and read 23605 times:
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Quoting pygmalion (Thread starter):
Per AV Week article from June 25, 2012, "The first two operators of the Boeing 787-8 are seeing better-than-anticipated fuel burn, despite prior expectations of below-par performance as a result of data from predelivery flight tests.

Great news once again. It sounds like Boeing have managed to mitigate more of the spec miss on the early birds than they originally anticipated, which bodes very well for later frames   

Quoting phxa340 (Reply 7):
Wouldn't this be an indication that on the longer sectors it is doing even better than 15-20% ?

The answer to that would appear to be “yes”, as the fuel burn saving per seat on longer sectors is reported to be better than the anticipated 20%. As the 787 is physically bigger and heavier, but with a much better SFC, it shouldn’t really be a surprise that its advantage is better over longer sectors..

Quoting tommytoyz (Reply 32):
The Aviationweek article does not say trip fuel burn

It might not. But that WAS the basis upon which the original data was reported as being based. I think this has subsequently been clarified, as Stitch has demonstrated.

Not that it needed clarification.
As for the seat-counts used for the comparison, any claim that the 21% per seat advantage is based on a 156 seat 787 versus a 175 seat 767 has to be utterly ludicrous, as it gives the 787 a more than 30% trip fuel burn advantage over its much smaller sister.
Will we ever know what seat counts were really underlying this number?
It doesn’t matter really I guess

The truth is that all that actually matters is that the initial planes are exceeding the figures that Boeing had advised the operators they would achieve. And that's good news  
Quoting tdscanuck (Reply 39):
Zeke, you're better than that. You know full well that a 20% increase in seats (which it isn't) doesn't drive a 20% increase in fuel.

Which is why of course he didn’t actually say that.   

Quoting Burkhard (Reply 46):
Congrats to have the 788 fuel burn better than expected. End good all good

Gets my vote   

Rgds


User currently offlineRevelation From United States of America, joined Feb 2005, 11929 posts, RR: 25
Reply 53, posted (1 year 9 months 3 weeks 5 days 8 hours ago) and read 23365 times:

Quoting lightsaber (Reply 15):
Requires a log in.
http://www.aviationweek.com/Article....l/avd_06_26_2012_p01-01-470896.xml

is publicly available. For us enginistas:

Quote:

GE says initial performance data show its GEnx-1B engine has a 2% fuel burn advantage over the competing Rolls-Royce Trent 1000, not counting an additional 1% benefit from expected performance retention in terms of sustained exhaust gas temperature margin.

...

Meanwhile, the FAA certificated the 75,000-lb.-thrust variant of its GEnx-1B PIP1 (product improvement package) upgrade on June 14. The engines already in service with JAL are also built to the PIP standard certificated in August 2011, but are rated at a lower thrust level.

PIP1 was designed to improve fuel burn by around 1.6% compared to the baseline GEnx-1B, although the latest in-service data suggest this may have been conservative. PIP1 included a new low-pressure turbine, a revised control schedule and hot section upgrades.

GE is currently developing a second PIP package which is aimed at an additional 1.1%. The upgrade builds on PIP1 and adds 0.5-in. to the fan diameter, optimized outlet guide vanes, improved high-pressure compressor aerodynamics, upgrades to the low-pressure compressor and durability enhancements to the combustor and high-pressure turbine. The second PIP will be certificated in the fourth quarter of this year and will enable thrust growth to 78,000 lb.


The evil empire struts its stuff!

Quoting packsonflight (Reply 49):
Why is the 787 compared to the 767 at all?

Because that's what JAL and ANA are going to use the 787 to replace...



Inspiration, move me brightly!
User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 54, posted (1 year 9 months 3 weeks 5 days 8 hours ago) and read 23218 times:

Quoting tommytoyz (Reply 32):
The Aviationweek article does not say trip fuel burn. What news articles are you referring to. Can you link any?


We discussed this last week in relation to the actual ANA press release which this AW&ST article is partly based upon. The graphic in my earlier post came from the actual Japanese version of the ANA press release.

http://www.ana.co.jp/pr/12_0406/12-035.html

ANA has two 787-8 configurations, one being 264 seat, the other 156 seat.
http://www.ana.co.jp/dom/inflight/seatmap/b8p/
http://www.ana.co.jp/wws/us/e/asw_common/inflight/seatmap/b787_8/

I do not think a 156 seat 787 has a blanket 21% per seat improvement over a 216 seat 763. I think that aircraft could have a higher per seat fuel cost over the 767 when used on medium and short haul routes whilst potentially uplifting less revenue payload.

That being said, I think that does not mean the aircraft cannot be meeting their expectations. I do not think for a second they thought the 787-8 in that configuration over shorter sectors would. In the ANA statement they specifically referred to 787 aircraft in the 220-250 seat category (not the long haul 156 seat configuration), the early ANA aircraft were 264 seat capacity.

ANA did not mention the saving on a comparison of the 767 vs 787 on the Tokyo-Frankfurt route, we concluded in that earlier thread that ANA has not operated the 767 over that route. The aircraft that the 787 is replacing on that route is the 777.

The statement also went on to say that they were achieving that savings on every flight, I did not believe that blanket statement, the 767 being considerably lighter, it should still have advantages on shorter trips. Some of ANAs international flights are very short, in the order of 90 minutes flight time.

Quoting tommytoyz (Reply 32):

CASM is an important metric. If that's not a convincing metric for you....you are free to raise your hand and state it's not an important metric in your mind.

I agree CASK (most of the world is metric) in an important statistic when used correctly, however in this case it is being abused. ANA does not have a single CASK for the 787, they have two configurations, likewise they have multiple 767 configurations.

Quoting tommytoyz (Reply 32):

Even if true, it does not change the advantages it has or change the numbers. But your thinking, that because the 787 has a heavier OEW, that it is natural for it to be 20% more efficient per seat, is overly simplistic.

I explained this in the previous thread, I do not believe the 787 enjoys a fixed fraction improvement over any aircraft, including the 767. The reason being is the number of variables involved.

This is what i said previously

"I do not think the 787 enjoys a fixed fraction performance advantage over the 767 over all ranges. An inspection of the Breguet Range Equation would indicates that the 787 would better than the 767 with propulsive efficiency and L/D, however it is not as structurally efficient. I understand they it has around 30,000 kg higher OEW in the ANA configuration. This means one should expect the relative performance advantage to change with range and payload."



That is by far the most objective statement made in relation to the ANA numbers.

Quoting tdscanuck (Reply 48):
If we credit the 787-8 40,000 lbs and take it up to 460,000 lbs for approximately equal payload, the 787-8 still burns 10% less fuel per hour.

Even at maximum weight (540,000 lbs) the 787-8 is only burning 10% more per hour but, at that weight, it's got far more range (or an extra 80,000 lbs of payload).

That is in line with my expectations, depending on sector length. I would expect over the shorter sectors for the same payload, the 763 would be better.

I did not believe it "burns 20% less fuel", the statement was made on a per seat basis by ANA. In relation to total payload, the 788 has 28 LD3 positions, and the 763 has 30 LD2 positions, and the different passenger layouts discussed above.

For a 264 seat configuration 787 one would assume that 11 LD3s would have passenger baggage (25 bags per LD3), for the 156 seat configuration, 7 LD3s for baggage, this leaves 17 and 21 LD3 available for cargo respectively. Industry average air cargo density is around 10 lb/cu.ft, each LD3 has around 153 cu.ft of internal space, assuming 100% load factors, this would mean 32130 lb, and 26010 lb of cargo respectively for each configuration.

For a 216 seat configuration 767 one would assume that 12 LD2s would have passenger baggage (19 bags per LD2), for the 216 seat configuration, 12 LD3s for baggage, this leaves 18 LD2s left for cargo. Again using the industry average of 10 lb/cu.ft and 116 cu.ft internal space per LD2, gives 20880 lb of cargo.

The 787 does carry more cargo, however this is mainly due to the larger cargo hold, it has around 20-25% more containerized volume.

Now what happens when you add the passengers to the cargo ?
156 passengers @ 220 lb each = 34320 lb (787 156 seats)
264 passengers @ 220 lb each = 58080 lb (787 264 seats)
216 passengers @ 220 lb each = 47520 lb (767 216 seats)

Looking at the combined passengers and cargo
787 156 seats = 34320 lb (passengers) 32130 lb (cargo) = 66450 lb
787 264 seats = 58080 lb (passengers) 26010 lb (cargo) = 84090 lb
767 216 seats = 47520 lb (passengers) 20880 lb (cargo) = 68400 lb

Now that is assuming 100% load factors for passengers and cargo, industry average is more like 75%. At 75% LF, the 767-300ER would have a lower ZFW than the 787-8 OEW.

Quoting tdscanuck (Reply 48):


Conclusion: based on *conservative* and certified data provided to all operators, it's entirely possible for the 787-8 to have double digit % *trip fuel* burn advantage over the 767-300, let alone per seat fuel burn.
Quoting Stitch (Reply 4):

And with a 787-8 with 156 seats installed, with a 10% lower trip fuel value could mean a 216 seat 767-300ER enjoys a 20%+ lower per seat burn. As I have also shown above, it may also carry more revenue payload.

As you would also recall, the aircraft that Boeing actually sold these carriers to replace the 767 on domestic and shorter sectors was the lighter, 787-3. That aircraft had not only the aerodynamic and propulsive advantages of the 787 design, it also was a lighter weight, this improving all three areas of the Breguet Range Equation.

The reason these carriers ordered the 787-3, is that it had operational advantages over the 787-8 for the shorter sectors. It should be of not surprise then that a 787-8 which is a long haul aircraft being "abused" on short international and domestic sectors is not as economical as the 787-3 or 763. The 787-8 was designed as a long haul aircraft, that is why it has significantly higher empty weight over the 767. The 787-8 has significantly greater range, and provides better passenger comfort compared to the 767-300ER, it is a clear winner on long haul flights.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinesweair From Sweden, joined Nov 2011, 1806 posts, RR: 0
Reply 55, posted (1 year 9 months 3 weeks 5 days 7 hours ago) and read 23080 times:

Quoting Revelation (Reply 53):
PIP1 was designed to improve fuel burn by around 1.6% compared to the baseline GEnx-1B, although the latest in-service data suggest this may have been conservative.

I read that it might be close to 2% actually. With PIP2 the engine should be at or below spec. And all the negative reports I have seen, should learn me not to trust aviation media.


User currently offlineFlighty From United States of America, joined Apr 2007, 8204 posts, RR: 3
Reply 56, posted (1 year 9 months 3 weeks 5 days 7 hours ago) and read 23031 times:

Quoting SEPilot (Reply 47):
But a Gulfstream G650 would have much lower trip cost. What does that prove?

Trip cost is what matters 9 months out of the year. In most markets. CRPM is what matters (cost per revenue pax mile). If your market has 6 people, the G650 is correct. If 50 people, an A319 LR is ideal (because its CRPM would be lower than an A380 for example).

My posit is, for markets under 200 passengers, the 763ER will have a cheaper cost per RPM than a 788, because it is a cheaper airplane that apparently burns equal fuel (per trip).

But we'll see. Not trying to rain on the 787 (which is awesome); only holding up a standard for how profitability is calculated. For a modest route, you want a modest airplane. And the 787 will win too, more and more often.


User currently offlinerheinwaldner From Switzerland, joined Jan 2008, 2198 posts, RR: 5
Reply 57, posted (1 year 9 months 3 weeks 5 days 7 hours ago) and read 22833 times:

Quoting tdscanuck (Reply 48):
Since the 787-8 and 767-300 cruise at about the same speeds, the per hour fuel burn is directly equivalent to the per trip fuel burn.

I am not sure about that one. I think there is a difference in cruise speed that strengthens the argument in favour of the 787  


User currently offlineSEPilot From United States of America, joined Dec 2006, 6680 posts, RR: 46
Reply 58, posted (1 year 9 months 3 weeks 5 days 7 hours ago) and read 22549 times:

Quoting Flighty (Reply 56):

Trip cost is what matters 9 months out of the year.

What matters most is making money. While trip costs are very important when planes are not full (as you correctly point out), a smaller plane has less ability to make money when it is. Airlines have to decide what is the right sized plane for a given route, and that is a different question than whether or not the 787 is exceeding expectations. From what I have been able to deduce from the information available, the 787 should cost no more to operate than the 767 when not full, and have substantially better earning capability when it is full. This is very good.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlinetarheelwings From United States of America, joined Jul 2009, 209 posts, RR: 0
Reply 59, posted (1 year 9 months 3 weeks 5 days 7 hours ago) and read 22245 times:

Quoting sweair (Reply 55):
The reason these carriers ordered the 787-3, is that it had operational advantages over the 787-8 for the shorter sectors. It should be of not surprise then that a 787-8 which is a long haul aircraft being "abused" on short international and domestic sectors is not as economical as the 787-3 or 763. The 787-8 was designed as a long haul aircraft, that is why it has significantly higher empty weight over the 767. The 787-8 has significantly greater range, and provides better passenger comfort compared to the 767-300ER, it is a clear winner on long haul flights.

These are all interesting facts and I would assume accurate....what I don't get is the constant need to inject a negative spin in what should be by most accounts a positive message:

Quoting pygmalion (Thread starter):
Per AV Week article from June 25, 2012, "The first two operators of the Boeing 787-8 are seeing better-than-anticipated fuel burn, despite prior expectations of below-par performance as a result of data from predelivery flight tests.

Per the quote above, both ANA and JAL are seeing better than anticipated fuel burn....why don't we leave it at that and congratulate Boeing on a job well done   


User currently offlineglideslope From United States of America, joined May 2004, 1594 posts, RR: 0
Reply 60, posted (1 year 9 months 3 weeks 5 days 6 hours ago) and read 21981 times:

Quoting tarheelwings (Reply 59):
er the quote above, both ANA and JAL are seeing better than anticipated fuel burn....why don't we leave it at that and congratulate Boeing on a job well done   

Agreed. Sit back and watch the new orders start to pour in.   



To know your Enemy, you must become your Enemy.” Sun Tzu
User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 61, posted (1 year 9 months 3 weeks 5 days 6 hours ago) and read 21145 times:
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Quoting zeke (Reply 54):
The reason these carriers ordered the 787-3, is that it had operational advantages over the 787-8 for the shorter sectors.

That was the plan, but once Boeing had detailed wind tunnel and CFD models they discovered that the 52m span proved to impact aerodynamic efficiency so much that it wiped out the advantages of the planned 10t lower OEW. The 787-8 proved to be more economical beyond about 250nm and both NH and JL subsequently converted their 787-3 orders to 787-8s and Boeing removed the 787-3 from offer.


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 62, posted (1 year 9 months 3 weeks 5 days 5 hours ago) and read 20857 times:

Quoting Stitch (Reply 61):
That was the plan, but once Boeing had detailed wind tunnel and CFD models they discovered that the 52m span proved to impact aerodynamic efficiency so much that it wiped out the advantages of the planned 10t lower OEW. The 787-8 proved to be more economical beyond about 250nm and both NH and JL subsequently converted their 787-3 orders to 787-8s and Boeing removed the 787-3 from offer.

That is news to me, I was of the understanding Boeing delayed the 787-3 development due to delays with the 787-8. The customers then decided to convert their 787-3 orders to 787-8.

Where did you see these CFD results ?

http://www.flightglobal.com/news/art...vour-of-longer-range-787-8-327758/
http://www.flightglobal.com/news/articles/ana-abandons-787-3-336950/



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineblueflyer From United States of America, joined Jan 2006, 3701 posts, RR: 2
Reply 63, posted (1 year 9 months 3 weeks 5 days 5 hours ago) and read 20760 times:
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Quoting abnormal (Reply 19):
As Boeing's target for FANS 2 certification was the first 787-9, and they have been denied an exemption for any non FANS 2 -8s aircraft after Jan 01 2014, anybody planning on operating a -8 into EU airspace is going to pretty annoyed until the retrofit is available.

Maybe this got deleted in the cleanup of the slug fest, but I'd really like to know what makes one think Boeing can't get the 787 compliant in time?

Quoting Viscount724 (Reply 31):
Do the magazines complain about Google hacking into their subscription-only publications

If they minded, they would put an end to it. Easy to do.



I've got $h*t to do
User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 64, posted (1 year 9 months 3 weeks 5 days 5 hours ago) and read 20608 times:
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Quoting zeke (Reply 62):
That is news to me, I was of the understanding Boeing delayed the 787-3 development due to delays with the 787-8. The customers then decided to convert their 787-3 orders to 787-8.

The 787-3 EIS was pushed back as the EIS of the 787-8 and 787-9 slipped and no new customers for the 787-3 came forward.


Quoting zeke (Reply 62):
Where did you see these CFD results?

I want to say I read about the performance difference in this forum, but it may have come from a source within the 787 program (with permission to make it public).

Honestly, even if the data showed the 787-3 to be better for intra-Japan missions, the lack of customer interest overall probably would have had Boeing try and get NH and JL to cancel and convert those orders to free up resources for the 787-10X.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 65, posted (1 year 9 months 3 weeks 5 days 2 hours ago) and read 19953 times:

Quoting zeke (Reply 54):
Quoting tommytoyz (Reply 32):
The Aviationweek article does not say trip fuel burn. What news articles are you referring to. Can you link any?
Quoting zeke (Reply 23):
, it was reported in the English press that this was 20% lower trip fuel.

So there are no English articles you can find and link to that you mentioned were published in the English press and you said were in error? The news article you linked to is in Japaneses, not English.

Quoting zeke (Reply 54):
I agree CASK (most of the world is metric) in an important statistic when used correctly, however in this case it is being abused. ANA does not have a single CASK for the 787

That is true, ANA does not have a CASM or CASK. But they did mention a per seat fuel burn comparisons between the 787 and 767. To which you conclude:

Quoting zeke (Reply 23):
In short, the numbers did not present anything in my view that was a convincing improvement over the 763.

It is plainly obvious that the 787-8 is massively more fuel efficient than the 767 and A330. If the composite advantages touted by Boeing pan out, it'll be cheaper on maintenance as well. We'll see on that yet though. I think there is a reason why AB is doing a "me too" with the A350 clean sheet. If the advantages weren't there, they wouldn't be doing it and the A350 XB or whatever it was called (the A330 derivative), would have sold in large numbers, but it didn't.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 66, posted (1 year 9 months 3 weeks 5 days 1 hour ago) and read 19914 times:

Quoting zeke (Reply 23):
In short, the numbers did not present anything in my view that was a convincing improvement over the 763.

If this were true, why is there almost no backlog for the 767, while the 787 has a backlog of almost 800 planes? Why wait 8 years for something when you can almost the same thing in 12 months? If that were true, the 767 would be selling strongly now, but it's not.


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 67, posted (1 year 9 months 3 weeks 5 days 1 hour ago) and read 19809 times:
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Quoting tommytoyz (Reply 65):
So there are no English articles you can find and link to that you mentioned were published in the English press and you said were in error? The news article you linked to is in Japaneses, not English.

Well NH is a Japanese company and it was a press release for the Japanese market.

[Edited 2012-06-27 12:06:50]

User currently offlinesweair From Sweden, joined Nov 2011, 1806 posts, RR: 0
Reply 68, posted (1 year 9 months 3 weeks 5 days 1 hour ago) and read 19709 times:

The 787 has one big disadvantage, its huge backlog and that will damped new orders for a while yet. But as airlines see a large number of 787s at other airlines and Boeing producing them in the 100s every year, orders will grow.

I expect to see more conversions from 788 to 789 and 787-10 when that gets firmed up. The 789 will be a much more "mature" frame than the first 90 788s..

If the 767 sold north of 1000 I am sure the 787 will sell north of 2000 over its life time. Heck even the 747 sold more than a 1000 frames.


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 69, posted (1 year 9 months 3 weeks 5 days 1 hour ago) and read 19755 times:

Quoting Stitch (Reply 64):

I want to say I read about the performance difference in this forum, but it may have come from a source within the 787 program (with permission to make it public).

Needless to say, the reason you provided does not sound reasonable. A 10t change in weight is significant, it is 100 passengers, have a look how this fits in with the range equation as well. For a 250 nm sector, you would never get into the cruise, you would climb up to TOD, and then glide down. 737NG operators that do not do long sectors do not get winglets as the drag improvements is not worth the extra weight over short sectors, the burn less fuel in the climb due to the lower weight, and then basically the same amount in descent as the engines are running at idle.

Quoting tommytoyz (Reply 65):
So there are no English articles you can find and link to that you mentioned were published in the English press and you said were in error?

"Mr. Ito said the 787 twinjets, which carry around 220 to 250 passengers, help the airline save around 21% of fuel consumption on each flight.",

from http://www.marketwatch.com/story/all...-international-capacity-2012-06-10

which is not what their Japanese press release states.

Quoting tommytoyz (Reply 65):
But they did mention a per seat fuel burn comparisons between the 787 and 767.

Which 767 and which 787 configuration ? Which routes ? What payload ?

The zero fuel weight of a 100% full 767-300ER in the ANA configuration is only around 2,000 lb heavier than a empty 787-8 (i.e. no payload).

Quoting tommytoyz (Reply 65):

It is plainly obvious that the 787-8 is massively more fuel efficient than the 767 and A330.

That is not evident across all ranges. One would expect the advantages to increase with range, the 787-8 is a ULH machine. When used domestically or on the shorter international flights, I do not think they are "massively more fuel efficient". Just like I do not expect a 777-300ER to be "massively more fuel efficient" than a 777-300 on short flights. They are designed for different markets.

Also need to keep in mind that for short sectors, fuel accounts for around 30% of the total costs, while ULH it is more like 60%. Their 767s would also be close to, if not already fully paid off, so the finance costs on the 767 fleet would be lower.

I have explained myself a number of times now, these metrics are clearly not linear. I have provided the mathematical basis above why this is the case, you cannot produce a linear result with that formula.

Quoting tommytoyz (Reply 65):
If the advantages weren't there, they wouldn't be doing it and the A350 XB or whatever it was called (the A330 derivative), would have sold in large numbers, but it didn't.

The original A350 sold well, better than the 777 did at the same time before EIS, I could go on, but that is for another topic, another time. I firmly believe a updated 767 with current technology engines would run circles around a 787 on short to medium haul sectors.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinetarheelwings From United States of America, joined Jul 2009, 209 posts, RR: 0
Reply 70, posted (1 year 9 months 3 weeks 5 days ago) and read 19561 times:

Quoting zeke (Reply 69):
That is not evident across all ranges. One would expect the advantages to increase with range, the 787-8 is a ULH machine. When used domestically or on the shorter international flights, I do not think they are "massively more fuel efficient". Just like I do not expect a 777-300ER to be "massively more fuel efficient" than a 777-300 on short flights. They are designed for different markets.

As you say, the 787 is an ULH plane which means that using it on short flights is not the most efficient way to utilize it.....I think we can all agree on this point. Having said that, isn't it possible that both ANA and JAL are aware of what the expected fuel burn would be for the 787 on short flights (based on the information given to them by Boeing), and that after using the 787 on these "inefficient" flights they have discovered that the actual fuel burn is actually better than expected? Wouldn't that be a positive development? Doesn't that actually mean that on long haul segments (the segments that the 787 is designed for according to your own words) the 787 will not only deliver on its promises but actually improve on them?

Quoting zeke (Reply 69):
I firmly believe a updated 767 with current technology engines would run circles around a 787 on short to medium haul sectors.

Boeing either doesn't agree with you or doesn't believe the business case supports such a plane......either way, it seems the only alternative is the 787....at least for those airlines that choose Boeing airplanes.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 71, posted (1 year 9 months 3 weeks 5 days ago) and read 19450 times:

Quoting zeke (Reply 23):
it was reported in the English press that this was 20% lower trip fuel.
Quoting zeke (Reply 69):
"Mr. Ito said the 787 twinjets, which carry around 220 to 250 passengers, help the airline save around 21% of fuel consumption on each flight.",

from http://www.marketwatch.com/story/all...-international-capacity-2012-06-10

You interpret the English news articles to say things about the 787, that they do not say. The English one you linked to does not compare trip fuel burn of the 787. The vaguely mention fuel savings of the 787, as ANA stated. ANA didn't get into all the gory details of how they came up with the number and the English news media reported the ANA statement accordingly vague.

Quoting tdscanuck (Reply 48):
Conclusion: based on *conservative* and certified data provided to all operators, it's entirely possible for the 787-8 to have double digit % *trip fuel* burn advantage over the 767-300, let alone per seat fuel burn.

Thanks for the clarity. I think it is plain as day, that by whatever metric you use, the 787 is more fuel miserly than the 767 by a long shot. Of course you can say, "well on a 100 mile leg with 20 passengers, etc."...but that's silly.

If the GE engines are indeed 1-2% better than the Rollers, so much the better for those operators and JAL. With the coming lower weights, the 787 advantage will only get better.

More interesting for me, is how the 787 compares to the latest 777W.

[Edited 2012-06-27 13:40:43]

User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 72, posted (1 year 9 months 3 weeks 4 days 23 hours ago) and read 19418 times:

You can always manipulate numbers to your advantage. Economists do this all day long. The point I think that is being overlooked is that ANA and JAL are very pleased with their 787s.

User currently offlinesbworcs From United Kingdom, joined Oct 2005, 825 posts, RR: 5
Reply 73, posted (1 year 9 months 3 weeks 4 days 23 hours ago) and read 19344 times:

Quoting blueflyer (Reply 63):
Quoting abnormal (Reply 19):
As Boeing's target for FANS 2 certification was the first 787-9, and they have been denied an exemption for any non FANS 2 -8s aircraft after Jan 01 2014, anybody planning on operating a -8 into EU airspace is going to pretty annoyed until the retrofit is available.

Maybe this got deleted in the cleanup of the slug fest, but I'd really like to know what makes one think Boeing can't get the 787 compliant in time?

Sorry to ask what might be a stupid question but can someone please explaing, in simple terms, what FANS 1 and FANS 2 are?

Thanks



The best way forwards is upwards!
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 74, posted (1 year 9 months 3 weeks 4 days 23 hours ago) and read 19289 times:

Something that often gets forgotten around this issue is that the early "bad" 787's are only "bad" relative *to the original 787 specs*. Compared to all other aircraft in production (i.e. not A350) even a "bad" 787 is a *fantastic* plane.

Quoting sbworcs (Reply 73):
Sorry to ask what might be a stupid question but can someone please explaing, in simple terms, what FANS 1 and FANS 2 are?

Future Air Navigation System 1 & 2.
http://en.wikipedia.org/wiki/Future_Air_Navigation_System

FANS-1 is basically CPDLC. I'm not sure what FANS-2 requires or why a 787 wouldn't be able to do it.

Tom.


User currently offlinebikerthai From United States of America, joined Apr 2010, 2011 posts, RR: 4
Reply 75, posted (1 year 9 months 3 weeks 4 days 23 hours ago) and read 19276 times:

Quoting zeke (Reply 69):
I firmly believe a updated 767 with current technology engines would run circles around a 787 on short to medium haul sectors.

People, you have to read zeke's post carefully. He is often on point. You just have to read between the lines to understand what he's saying.

Even if he firmly believe the statement above, he would not disagree that the 787 is a better plane for ANA and JAL because while the 787 is not as efficient at the sort route, it can do both long and short. Where as the 767 can not do the UL route.

I don't think he's anti 787. He, like me, just like be a devil's advocate just to make sure all ideas are on the table.

bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlineEPA001 From Netherlands, joined Sep 2006, 4593 posts, RR: 38
Reply 76, posted (1 year 9 months 3 weeks 4 days 22 hours ago) and read 19127 times:
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Quoting bikerthai (Reply 75):
People, you have to read zeke's post carefully. He is often on point. You just have to read between the lines to understand what he's saying.

He sure is. And his assumptions on (relatively very) short range flights, where the B767 has an enormous weight advantage over the B787-8, are only logical.


User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 77, posted (1 year 9 months 3 weeks 4 days 22 hours ago) and read 19041 times:

[quote=bikerthai,reply=75]I don't think he's anti 787. He, like me, just like be a devil's advocate just to make sure all ideas are on the table.

Agreed but when you are devils advocate for one supplier , you need to approach the other supplier with the same skepticism , otherwise - your logic doesn't work  


User currently offlineUALWN From Andorra, joined Jun 2009, 2654 posts, RR: 2
Reply 78, posted (1 year 9 months 3 weeks 4 days 22 hours ago) and read 19018 times:

Quoting phxa340 (Reply 77):
Agreed but when you are devils advocate for one supplier , you need to approach the other supplier with the same skepticism

Don't worry: there's no shortage in a.net of devil's advocates for "the other supplier."



AT7/111/146/Avro/CRJ/CR9/EMB/ERJ/E75/F50/100/L15/DC9/D10/M8X/717/727/737/747/757/767/777/AB6/310/319/320/321/330/340/380
User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 79, posted (1 year 9 months 3 weeks 4 days 22 hours ago) and read 19009 times:

Quoting UALWN (Reply 78):
Don't worry: there's no shortage in a.net of devil's advocates for "the other supplier."

  , no argument there !


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 80, posted (1 year 9 months 3 weeks 4 days 22 hours ago) and read 19036 times:

Quoting bikerthai (Reply 75):
because while the 787 is not as efficient at the sort route,

First of all, this contradicts what ANA said, while deploying the 787 on their short routes.

Secondly, the CASM advantage the 787 enjoys over the 767 is more than the advantages the engines alone provide.

Thirdly, let's be realistic, 787 size aircraft (and larger) are not operated with great frequencies on 300 - 500 mile segments except in Japan. Realistically one would compare the performance of various aircraft on the missions they are intended for and operated on, not some fringe route. Or are we going to start saying how terrible the A380 is on short hops? That, of course, is a silly notion.


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 81, posted (1 year 9 months 3 weeks 4 days 22 hours ago) and read 19001 times:

Quoting tarheelwings (Reply 70):
As you say, the 787 is an ULH plane which means that using it on short flights is not the most efficient way to utilize it.....I think we can all agree on this point. Having said that, isn't it possible that both ANA and JAL are aware of what the expected fuel burn would be for the 787 on short flights (based on the information given to them by Boeing), and that after using the 787 on these "inefficient" flights they have discovered that the actual fuel burn is actually better than expected? Wouldn't that be a positive development?

I said above that I think the 787 is meeting their expectations, whatever those expectations were, they are not sharing them. I also believe the have competent fleet planners, and they were aware the 787-8 was not the optimum aircraft for all routes, no aircraft ever is. I am also think they were aware of how efficient the 767 was for them on the shorter sectors, the continued to invest in them, including the addition of winglets.

That being said, the blanket statement of X% "better than expected" I cannot agree with, as the maths does not back those numbers up. The statement is too simplistic for a complex problem with so many variables. For example, the very first flight to HKG they did they put out a press release to say the aircraft is doing 20% better, no one in industry believed that, a single datapoint is not enough to make any sort valid comparison over.

When I read the claims Boeings was making about the 787 relative to the 767, I could only think they were meaning the 787 with the design payload over the design range vs the 767 with the design payload over the design range, they were never specific, this in my view always gave them some wiggle room.

Quoting tommytoyz (Reply 71):

You missed the previous thread where this was discussed when the original ANA press release came out. The AW&ST article is a rehash of other articles. If you were to do a web search on the terms found in the market watch article, you will see other articles in the English press.

Quoting tdscanuck (Reply 74):

FANS-1 is basically CPDLC. I'm not sure what FANS-2 requires or why a 787 wouldn't be able to do it.

Only the 744 as far as I am aware is FANS 2, everything else is FANS 1. It will a matter of a simple upgrade to get them to FANS 2, all schedule to happen before 2014. Airbus already has a number of platforms flying with their version of FANS 2 called FANS B including the A320, A330, A340, & A380.

The main difference is speed and bandwidth, FANS 1/ FANS A uses the slower ACARS network. FANS 2/ FANS B uses a new Aeronautical Telecommunications Network with a couple of VHF datalink transceivers. An additional mandate is in place for the datalink messages are recorded to the CVR.

The next step will be the so called free flight, that is schedule for 2018.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 82, posted (1 year 9 months 3 weeks 4 days 20 hours ago) and read 18624 times:

Quoting zeke (Reply 81):
If you were to do a web search on the terms found in the market watch article, you will see other articles in the English press.

You made the claim about how the English media were falsely reporting on the 787, not I. And when you finally did link to an English article, it didn't say what you claimed. If such reporting actually exists, you should be able to link to at least one. I'll just take it they do not exist, since you have not been able to find any.


And let's get the notion that the 767 is better on short hops in Japan than the 787, because it's lighter - right out of our heads. ANA clearly says it:
"On domestic routes, the saving is 15-20%, which meets expectations, say ANA officials."

- An this with overweight planes and the 1st Rollers.

Quoting Stitch (Reply 64):
The 787-3 EIS was pushed back as the EIS of the 787-8 and 787-9 slipped and no new customers for the 787-3 came forward.

I doubt the 787-3 will ever be built. I think the niche market is just too small to justify it and the marginal savings too low. Like the 747 version the Japanese once requested, with fixed landing gear, they weren't built either.


User currently onlineXT6Wagon From United States of America, joined Feb 2007, 3321 posts, RR: 4
Reply 83, posted (1 year 9 months 3 weeks 4 days 20 hours ago) and read 18596 times:

Quoting tommytoyz (Reply 82):
I doubt the 787-3 will ever be built

yah, Any "domestic" 787 will be a normal model with a paper derate. I assume the 789 or 781 being the most popular.


User currently onlineViscount724 From Switzerland, joined Oct 2006, 24075 posts, RR: 22
Reply 84, posted (1 year 9 months 3 weeks 4 days 19 hours ago) and read 18568 times:

Quoting tdscanuck (Reply 48):
Since the 787-8 and 767-300 cruise at about the same speeds

I somehow had the impression that the 787, being designed 30 years after the 767, would have improved on the 767s rather slow cruising speed. I believe the 767 is one of the slowest widebodies.


User currently onlineXT6Wagon From United States of America, joined Feb 2007, 3321 posts, RR: 4
Reply 85, posted (1 year 9 months 3 weeks 4 days 19 hours ago) and read 18489 times:

Quoting Viscount724 (Reply 84):
I somehow had the impression that the 787, being designed 30 years after the 767, would have improved on the 767s rather slow cruising speed. I believe the 767 is one of the slowest widebodies

It is. Its quoted cruise speed .85 while the cruise speed of the 767 is .80.


User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 86, posted (1 year 9 months 3 weeks 4 days 19 hours ago) and read 18429 times:

Quoting lightsaber (Reply 15):
Many are waiting for LN90+ which should meet empty weight promise (and have a higher MTOW

So what is this weight expected to be? From the links in the post ; The first was 9.8t over weight LN7 to 19, 6.1t over and at LN 20 4 t. over. My question is , over what ? PIANO X used a weight of 114.532t for the base model. Is this the weight that is being referred to.   


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 87, posted (1 year 9 months 3 weeks 4 days 19 hours ago) and read 18419 times:
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Quoting sunrisevalley (Reply 86):
So what is this weight expected to be?

Boeing's last ACAP figure for an OEM configuration was 112t.


User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 88, posted (1 year 9 months 3 weeks 4 days 19 hours ago) and read 18371 times:

Quoting Stitch (Reply 87):
Boeing's last ACAP figure for an OEM configuration was 112t.

In this context is OEM the same as MEW ?


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 89, posted (1 year 9 months 3 weeks 4 days 18 hours ago) and read 18374 times:

Quoting EPA001 (Reply 76):
He sure is. And his assumptions on (relatively very) short range flights, where the B767 has an enormous weight advantage over the B787-8, are only logical.

They're logical given Zeke's core assumption...that the dominant driver in the Brueget range equation is the weight. The actual in service data shows that's not the case. The improved L/D and SFC of the 787-8 dominate over the weight term except at extremely short ranges (where both the 767 and 787 are ill suited).

Quoting zeke (Reply 81):
When I read the claims Boeings was making about the 787 relative to the 767, I could only think they were meaning the 787 with the design payload over the design range vs the 767 with the design payload over the design range

I agree that was one logical interpretation but the actual numbers coming out of airlines, and in the published manuals, show that's not the case.

Quoting Viscount724 (Reply 84):
I somehow had the impression that the 787, being designed 30 years after the 767, would have improved on the 767s rather slow cruising speed. I believe the 767 is one of the slowest widebodies.

You're right; I was thinking 777 cruise speed. The 767 does go slower, as XT6Wagon pointed out. This biases the analysis *more* in favour of the 787 since the 787 is burning less fuel while going faster.

Tom.


User currently offlinecol From Malaysia, joined Nov 2003, 2087 posts, RR: 22
Reply 90, posted (1 year 9 months 3 weeks 4 days 18 hours ago) and read 18300 times:

Quoting tommytoyz (Reply 80):
Thirdly, let's be realistic, 787 size aircraft (and larger) are not operated with great frequencies on 300 - 500 mile segments except in Japan. Realistically one would compare the performance of various aircraft on the missions they are intended for and operated on, not some fringe route. Or are we going to start saying how terrible the A380 is on short hops? That, of course, is a silly notion.

Come to Asia, the widebody long haulers are used and abused on short legs every minute of the day.


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 91, posted (1 year 9 months 3 weeks 4 days 18 hours ago) and read 18240 times:
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Quoting sunrisevalley (Reply 88):
In this context is OEM the same as MEW ?

MEW usually refers to an airplane with no interior fittings, whereas OEW includes seats, lavatories, galleys and such.

Boeing defines OEW as follows in their ACAPS: "Weight of structure, powerplant, furnishing systems, unusable fuel and other unusable propulsion agents, and other items of equipment that are considered an integral part of a particular airplane configuration. Also included are certain standard items, personnel, equipment, and supplies necessary for full operations, excluding usable fuel and payload."

Airbus defines OEW as follows in their ACAPS: "Weight of structure, powerplant, furnishings, systems, and other items of equipment that are an integral part of a particular aircraft configuration plus the operator’s items. The operator’s items are the flight and cabin crew and their baggage, unusable fuel, engine oil, emergency equipment, toilet chemical and fluids, galley structure, catering equipment, seats, documents, etc."


User currently offlineCM From , joined Dec 1969, posts, RR:
Reply 92, posted (1 year 9 months 3 weeks 4 days 14 hours ago) and read 17898 times:

Quoting zeke (Reply 81):
When I read the claims Boeings was making about the 787 relative to the 767, I could only think they were meaning the 787 with the design payload over the design range vs the 767 with the design payload over the design range, they were never specific, this in my view always gave them some wiggle room.

The Boeing claim of the 787-8 delivering 20% lower fuel burn per seat versus the 767-300ER is per the following rules:

     Boeing long range interior rules (3-class), results in 242 in the 787 and 218 in the 767.
     Full pax & bags at (not sure, but probably 95kg/pax) and no rev cargo.
     6,000nm (which is FVL for the 767)

Boeing is always specific. The rules are always listed. A quick search on Google turned up this: http://www.boeingcapital.com/einvite...presentations/BradT_FI_2012_NY.pdf and you can bet if Boeing is including rule sets in public presentations, they are certainly including them when talking to customers.


User currently offlineferpe From France, joined Nov 2010, 2792 posts, RR: 59
Reply 93, posted (1 year 9 months 3 weeks 4 days 12 hours ago) and read 17628 times:

Quoting CM (Reply 92):
Boeing is always specific. The rules are always listed. A quick search on Google turned up this: http://www.boeingcapital.com/einvite...presentations/BradT_FI_2012_NY.pdf and you can bet if Boeing is including rule sets in public presentations, they are certainly including them when talking to customers.

It might be they are doing this for B frames, in the recent document the A358 is put as a 7800nm spec config aircraft angainst a 788 of 242pax with 7750nm range at page 12. We all know this is a VERY mature 788 (including 2 PIPs on the GE engines) and the A350 is judged as loosing 700! nm as compared to A specs. That is a lot and at worst might be the case for the first frames of the FAL but if apples are apples it should also be a mature A358. All this is explained by a caveat "Boeing assessment at Airbus MTOW". I can't make sense of that sentence to start with, does this mean B questions the MTOW or makes the more normal assumptions on the 358 OEW (which is not given by A by the way).

The same story happens for e.g. the 350-1000, it is labeled as having a 7775nm design range when Airbus states 8400nm, slide 27. Once again this funny caveat now not even denoted to a specific value but for the slide in general.

Such statements makes the whole B vs A comparison dubious for this slide-set IMO.

[Edited 2012-06-28 01:02:44]


Non French in France
User currently offlinerheinwaldner From Switzerland, joined Jan 2008, 2198 posts, RR: 5
Reply 94, posted (1 year 9 months 3 weeks 4 days 10 hours ago) and read 17443 times:

Quoting tommytoyz (Reply 65):
I think there is a reason why AB is doing a "me too" with the A350 clean sheet. If the advantages weren't there, they wouldn't be doing it and the A350 XB or whatever it was called (the A330 derivative), would have sold in large numbers, but it didn't.

I agree, there is a reason indeed. It is fully justified to highlight the benefits of a full cfrp vs. an aluminium aircraft. Except if the aluminium aircraft is the 777 and the full cfrp aircraft is the A350...


User currently offlineSEPilot From United States of America, joined Dec 2006, 6680 posts, RR: 46
Reply 95, posted (1 year 9 months 3 weeks 4 days 10 hours ago) and read 17352 times:

Quoting rheinwaldner (Reply 94):
Except if the aluminium aircraft is the 777 and the full cfrp aircraft is the A350...

There is justification for your skepticism certainly. I was one who was arguing that the A350 needed to go full CFRP to compete effectively with the 787, and that the 777 would have difficulty competing with the A350 with just an upgrade. I do think now, however, that the 777NG as planned will be enough larger than the A3510 that it will be competitive; I still think that a new large aircraft (Y3) would be better, but that clearly cannot happen within the necessary time frame, and Boeing cannot afford to just surrender this market. As it is, they are losing the 772 market, but part of it will be taken by the 7810 (which will also take most of the A333 market.)



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineBurkhard From Germany, joined Nov 2006, 4360 posts, RR: 2
Reply 96, posted (1 year 9 months 3 weeks 4 days 9 hours ago) and read 17256 times:

Quoting tarheelwings (Reply 59):
Per the quote above, both ANA and JAL are seeing better than anticipated fuel burn....why don't we leave it at that and congratulate Boeing on a job well done

Can't say better, and propose to add RR and GE into the congratulations, since a good deal of this is with their merits.


User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 97, posted (1 year 9 months 3 weeks 4 days 7 hours ago) and read 17063 times:

Quoting Stitch (Reply 91):
MEW usually refers to an airplane with no interior fittings, whereas OEW includes seats, lavatories, galleys and such

Then I asume your use of the term OEM was a typo  

[Edited 2012-06-28 05:56:29]

User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 98, posted (1 year 9 months 3 weeks 4 days 7 hours ago) and read 17024 times:

Quoting Stitch (Reply 91):
Also included are certain standard items, personnel

TK in calculating the DOW of their aircraft add in the crew weight. For example, for the 77W they use a 167.556t OEW and add potable water, crew , crew baggage and pantry for a 4.106t DOW add on.


User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 99, posted (1 year 9 months 3 weeks 4 days 7 hours ago) and read 16971 times:

Quoting sunrisevalley (Reply 98):
TK in calculating the DOW of their aircraft add in the crew weight. For example, for the 77W they use a 167.556t OEW

Mea cupla...I should have checked further. The 77W OEW quoted above is some .273t less than the OEW in the Boeing ACAP sheets. So I assume what is happening is that TK are deducting the crew weight component that Boeing uses in their OEW ccalculation and adding back their own based on their crewing standards.   


User currently offlineCM From , joined Dec 1969, posts, RR:
Reply 100, posted (1 year 9 months 3 weeks 4 days 5 hours ago) and read 16845 times:

Quoting ferpe (Reply 93):
Such statements makes the whole B vs A comparison dubious for this slide-set IMO.

Hi Ferpe. I wasn't trying to further the discussion of anything other than Boeing's comparison of the 787-8 to the 767-300ER. That comparison is controversial enough, let alone comparisons to competitor products which have yet to fly.

Quoting ferpe (Reply 93):
All this is explained by a caveat "Boeing assessment at Airbus MTOW". I can't make sense of that sentence to start with, does this mean B questions the MTOW or makes the more normal assumptions on the 358 OEW (which is not given by A by the way).

Point me to the thread in which you would like this statement explained and I will do so. I fear doing it here will derail this thread miserably.


User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 101, posted (1 year 9 months 3 weeks 4 days 5 hours ago) and read 16770 times:

Here are two links that are relevant to this discussion

aeroturbopower.blogspot.com/2011/11/b787-8-analysis.html
lissys.demon.uk/boeing787-2011.html.
If they have been mentioned earlier, my apologies.


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 102, posted (1 year 9 months 3 weeks 4 days 5 hours ago) and read 16890 times:
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Quoting sunrisevalley (Reply 97):
Then I asume your use of the term OEM was a typo.  

Not at all.

The 112t OEW is with a Boeing 224-seat three-class OEM interior. I specifically note this because Boeing traditionally uses a premium cabin product more representative of the 1980s then the 2010s so an actual customer DOW should be higher.

I will note that the 787-8 ACAP does offer two configs - one in the 1980s (224 seats) and one representing current premium cabin hard product standards (187 seats).


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 103, posted (1 year 9 months 3 weeks 4 days 4 hours ago) and read 16730 times:

Quoting tommytoyz (Reply 80):

First of all, this contradicts what ANA said, while deploying the 787 on their short routes.

ANA were not specific regarding the routes.

Quoting tommytoyz (Reply 82):

"On domestic routes, the saving is 15-20%, which meets expectations, say ANA officials."

Which contradicts their actual Japanese version of their press release I posted above. The original Japanese version in their graphic showing the savings, shows it being on a per seat basis. In their domestic configuration, the 787-8 has around 20% more seats than a 767-300ER does anyway, if they burn the same amount of trip fuel, the aircraft with more seats will burn less per seat.

Quoting Viscount724 (Reply 84):
I somehow had the impression that the 787, being designed 30 years after the 767, would have improved on the 767s rather slow cruising speed. I believe the 767 is one of the slowest widebodies.

On short flights aircraft often just get to top of climb and essentially are then are close to idle for the remainder of the of the flight while descending. Airspace restrictions normally prevent aircraft from accelerating to their optimum climb speeds below 10,000 ft, normally restricted to 250 kts in Japan. Their STARs often have speed requirements of 280 kts, and require the aircraft to be lower than normal. The idea being this provides an inverted cone shaped airspace where departing aircraft will be above arriving aircraft.

On shorter sectors I have seen cases where theoretically slower DC-8 can have shorter sector times than a 737-800, when intellectually it does not seem possible, e.g. SYD-CBR.

Quoting tdscanuck (Reply 89):

They're logical given Zeke's core assumption...that the dominant driver in the Brueget range equation is the weight.

I actually stated above that the 787 has the advantage with L/D and engines, but it not as structurally efficient. And have shown above how a full ANA 767 zero fuel weight with 216 seats would only be around 2,000 lb heavier than one of their completely empty 787-8s without a single passenger on-board.

As the sector length changes, the L/D and propulsive efficiency terms become dominate and eat into the weight difference, and there is a cross over point where the 787 comes out in front on a per seat, and per freight tonne Km basis. This is not a linear relationship.

I have consistently said I do not believe there is a fixed fraction advantage of the 787 over the 767, and nobody has presented any information which contradicts that.

Quoting tdscanuck (Reply 89):
The improved L/D and SFC of the 787-8 dominate over the weight term except at extremely short ranges (where both the 767 and 787 are ill suited).

Agreed, I have said this a number of times. However it has been reported they they are enjoying a fixed fraction advantage on EVERY flight, the 787-8 is worse than the 767 on these sectors.

Quoting tdscanuck (Reply 89):
I agree that was one logical interpretation but the actual numbers coming out of airlines, and in the published manuals, show that's not the case.

The airlines have been very careful with the language used in their statements. One cannot draw any firm conclusions as they are left a lot open to interpretation, i.e. the aircraft seating configurations, routes, and payloads are all unknown. We are not even sure if they were comparing the 787 to the 767 or 777 in ANAs case, as it could mean the 777 on the FRA route. That does not detract from them not being pleased with them, which I think is the message they are trying to get across. The press release in my view had a target audience being the passengers and shareholders, and I think it provides enough information to keep them happy.

You presented some information above from the FCOMs which demonstrates exactly what I have been saying all along.

Quoting CM (Reply 92):
The Boeing claim of the 787-8 delivering 20% lower fuel burn per seat versus the 767-300ER is per the following rules:

That is the first time I had seen that, logically I never expected it to be over shorter sectors. These rules were not published by Boeing when the claims were originally made around the time of the 787 launch. I looked for them. Back then they were not even saying 767, they were saying something like comparable twin engine aircraft.

Quoting CM (Reply 92):
Boeing is always specific

I beg to differ, this is typical of how the claim was presented, fuel consumption per seat, vs trip fuel. Range and payload were not specified.

http://i15.photobucket.com/albums/a357/thezeke/787/db71ff2a.png

Quoting sunrisevalley (Reply 99):
So I assume what is happening is that TK are deducting the crew weight component that Boeing uses in their OEW ccalculation and adding back their own based on their crewing standards.

Aircraft are physically put on scales and the mass is recorded after they are built, and this gets redone when they have a major configuration change or when required by their local CAA. Items are added to get the operators OEW, this will vary from airline to airline, and country to country as they have their own requirements, e.g. EU requirements are not the same as FAA requirements. Unless an airline has the exact same configuration as the manufacturer uses for their OEW (which normally is just done by calculation, the manufacturers do not build that interior), one always expects a difference. These numbers are a guide only.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineferpe From France, joined Nov 2010, 2792 posts, RR: 59
Reply 104, posted (1 year 9 months 3 weeks 4 days 4 hours ago) and read 16677 times:

Quoting CM (Reply 100):
Point me to the thread in which you would like this statement explained and I will do so. I fear doing it here will derail this thread miserably.

Agree, lets start a thread at Tech/Ops on how manufacturers compare aircraft with this as an example, we know the A are doing the same kind of exercises (placing 5t adder on the frame which is flying and not on the one who is not out of detail design  Wow! ) so will be interesting to discuss, but not here.



Non French in France
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 105, posted (1 year 9 months 3 weeks 4 days 2 hours ago) and read 16398 times:

Quoting zeke (Reply 103):
Quoting tommytoyz (Reply 82):

"On domestic routes, the saving is 15-20%, which meets expectations, say ANA officials."

Which contradicts their actual Japanese version of their press release I posted above.

There is no contradiction. I think that perhaps the problem is that you have a hard time believing in what is being said. Since the Japanese language press release doesn't mention route lengths, there is no contradiction with the English quote in Aviationweek which does mention short routes. I don't know why you insist on seeing things that are not there.


Quoting zeke (Reply 103):
The original Japanese version in their graphic showing the savings, shows it being on a per seat basis.

It only shows the savings, not the route lengths they are achieved on, as per your own translation.

Nobody is going to give any credibility to vague statements like "in another thread", "elsewhere", "above", "In the media", "I have previously said", "repeatedly" etc... - without any links or references what so ever.

Quoting zeke (Reply 103):
Quoting CM (Reply 92):
The Boeing claim of the 787-8 delivering 20% lower fuel burn per seat versus the 767-300ER is per the following rules:

That is the first time I had seen that, logically I never expected it to be over shorter sectors

The 737NG (even without winglets) is heavier than all other previous versions of the 737 that came before it. But it is still the most efficient 737 version even on short hops, say LAX to LAS - 300 miles. The same as the 787/767. Again, just because it's heavier, does not automatically mean it's less efficient on short hops. You certainly do not know what the L/D differences are between 787 and 767.

Which makes your statement that the 787 is

Quoting zeke (Reply 103):
not as structurally efficient

Startling.

As an example - The 737NG, had to be heavier than previous versions (737-700 has 12,000lbs over 737-300) because of larger wings, higher aspect ratios wing layout and heavier engines - same as the 787/767 comparison. Building wings with higher aspect ratios - like on the 787 - also creates heavier wings (all else equal) than the lower aspect ratio wings of the 767. Add in support for the heavier engines - and you will have a heavier, but more efficient aircraft. If done right, more efficient even on short hauls, like the 737NG vs older and lighter 737s.

[Edited 2012-06-28 11:21:43]

User currently offlineSEPilot From United States of America, joined Dec 2006, 6680 posts, RR: 46
Reply 106, posted (1 year 9 months 3 weeks 4 days 2 hours ago) and read 16346 times:

Quoting tommytoyz (Reply 105):
Which makes your statement that the 787 is

Quoting zeke (Reply 103):
not as structurally efficient

Startling.

Well, as an engineer, my definition of structural efficiency is the ratio of payload weight to empty weight. I am not an aircraft engineer, and they may use a different definition, but I doubt it. And so I expect that Zeke is exactly right. That does not, however, have anything to do with operating efficiency.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 107, posted (1 year 9 months 3 weeks 4 days 1 hour ago) and read 16276 times:

Quoting SEPilot (Reply 106):
Well, as an engineer, my definition of structural efficiency is the ratio of payload weight to empty weight

The 787-8 is more structurally efficient vs the 767-300ER (Winglets).

The 787 lifts the equivalent of 107% of its OEW
The 767 lifts the equivalent of 106% of its OEW

Despite having a structure that is heavier to built in general, as in having higher aspect ration wings (thinner as viewed from above).

If you're checking my math, don't forget to add the 3,000lbs for the winglets on the 767

The data is from Wiki, so forgive me if I have sinned......

[Edited 2012-06-28 11:48:50]

[Edited 2012-06-28 11:57:03]

User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 108, posted (1 year 9 months 3 weeks 4 days 1 hour ago) and read 16237 times:

Quoting tommytoyz (Reply 105):
There is no contradiction.

The contradiction is the the normalization on the per seat basis is missing which is what ANA had in their Japanese press release. See the calculation below why the seating configuration is the key to the statement.

Quoting tommytoyz (Reply 105):
The same as the 787/767. Again, just because it's heavier, does not automatically mean it's less efficient on short hops. You certainly do not know what the L/D differences are between 787 and 767.

The analysis has been done http://www.lissys.demon.co.uk/boeing787-2011.html, they also have a good analysis of both the 767 and 787 L/D.

Short haul : summary 767 can burn slightly less block fuel.

"The B787-8 is used by ANA in domestic and regional service over distances of 300 to 1200 nm (HND-OKJ, HND-PEK). Such usage is ill-matched to intrinsic design-sizing considerations for this aircraft. For example, when carrying 25 tonnes over 1000 nm the B787-8 burns approximately 10.6 tonnes of fuel (and more for early deliveries with acknowledged performance shortfalls). In contrast, a B757-300W is better sized to carry the same payload over the same distance, burning merely 8.6 tonnes despite its senescence, albeit at economy-class comfort levels (no deterioration, best engine option). The B767-300ERW burns 10.3 tonnes under the same circumstances. The factual significance and operational reality of such (counter-expectational) mission-specific fuel burns can appear negated or reversed through contrived definitions of efficiency metrics based on point conditions."

I highlighted that sentence as it is very relevant to the discussion.

Looking at the ANA configurations
787-8 264 and 158 seat configurations

10600/264 = 40.1 kg/seat
10600/158 = 67.0 kg/seat

767-300ER configurations
270, 214, 202 seat configurations

10300/270 = 38.1 kg/seat
10300/214 = 48.1 kg/seat
10300/202 = 50,9 kg/seat

As you can see, the 767 is burning less trip fuel than the 787-8, and depending on the configurations compared, also burns less per seat.

Long haul : summary 787 can burn slightly less block fuel.

"For a typical mission carrying 22 metric tonnes over 5000 nm (roughly HND-FRA), the block fuel burn of the B787-8 is calculated to be 50.1 tonnes. This compares to 50.7 tonnes for the B767-300ERW based on nominal performance (no in-service deterioration) and common reserve-rule assumptions that can be accessed via the models. Plots of fuel burn as a function of distance and payload are given below at the same transparent conditions. "

This analysis is a bit extreme, as the 787 would be able to carry more payload further. However this does show that the blanket statements being made do not match up with the results of some fairly comprehensive analysis.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineSEPilot From United States of America, joined Dec 2006, 6680 posts, RR: 46
Reply 109, posted (1 year 9 months 3 weeks 4 days 1 hour ago) and read 16185 times:

Quoting tommytoyz (Reply 107):
The 787-8 is more structurally efficient vs the 767-300ER (Winglets).

The 787 lifts the equivalent of 107% of its OEW
The 767 lifts the equivalent of 106% of its OEW
OK, I stand corrected. I assumed Zeke was using accurate figures. But your figures dispute that, and put the 787 as more structurally efficient. Take the winglets off, and I suspect they are pretty close, though.

[Edited 2012-06-28 12:10:24]


The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 110, posted (1 year 9 months 3 weeks 4 days 1 hour ago) and read 16124 times:

Quoting zeke (Reply 108):
As you can see, the 767 is burning less trip fuel than the 787-8

According to whom? Your link does not work. From what you are saying, it is 1) an independent analysis by someone (in 2011? By whom?), 2) making assumptions about the 787-8s performance.

Quoting zeke (Reply 108):
However this does show that the blanket statements

While the above mentioned analysis may "show" this, making assumptions, which are most likely different from the real world numbers.

Quoting zeke (Reply 108):
However this does show that the blanket statements being made do not match up with the results of some fairly comprehensive analysis.

I do not know what blanket statements you are referring to. Please link (that works).

Quoting zeke (Reply 108):
The contradiction is the the normalization on the per seat basis is missing which is what ANA had in their Japanese press release.

This makes zero sense. The two do not contradict as even you say, they are both talking about different things. Apples and Oranges and you want to see a contradiction there.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 111, posted (1 year 9 months 3 weeks 4 days 1 hour ago) and read 16117 times:

Quoting SEPilot (Reply 109):
Take the winglets off, and I suspect they are pretty close, though.

The 767-300ER without winglets is actually more structurally efficient that the 787-8. That's why I added the winglets into the 767 calculation...haha. In any case, they're both pretty evenly matched. To come out and say how inferior one is over the other on that metric, is silly.

BTW, ANA 767s do have winglets....so for ANA that's the wiki math.


User currently onlinemham001 From United States of America, joined Feb 2005, 3389 posts, RR: 2
Reply 112, posted (1 year 9 months 3 weeks 4 days ago) and read 16046 times:

This whole debate, and that of the other thread is based on the parsing of words spoken in another language. It's amusing how some have a need to argue about what was never said.

There is no getting over the fact that these two airlines seem to be very happy. How would a Japanese executive reconcile with their shareholders. etc when the next airline to receive delivery announces (with data) that their words were lies?

Will these Japanese executives commit hari kari once they are so easily exposed as liars or will the whole industry conspire to make the 787 better than it actually is?


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 113, posted (1 year 9 months 3 weeks 4 days ago) and read 16037 times:

Quoting SEPilot (Reply 106):
Well, as an engineer, my definition of structural efficiency is the ratio of payload weight to empty weight. I am not an aircraft engineer, and they may use a different definition, but I doubt it. And so I expect that Zeke is exactly right. That does not, however, have anything to do with operating efficiency.

The structural efficiency I was referring to was in relation to the formula in reply 54. It is the natural log of the ratio of takeoff weight divided by the landing weight, and I was made in the context of short sectors. As the ratio is greater on the 767, the airframe is more structurally efficient on short sectors.

Neither aircraft would be close to MTOW, MZFW, or MLW, the closest limit would be MZFW both are under that by 10+t. I do not think they could reach maximum zero fuel weight in those configurations. I have outlined what I think would be nominal maximum payloads for various configurations in reply 54 given industry average density for air freight and standard OEM numbers for passenger and baggage weights.

Naturally if one uses the incorrect numbers in the equation, or fails to understand the context the comments were made, one will not arrive with the correct answer to the problem at hand.

Quoting tommytoyz (Reply 110):
According to whom? Your link does not work. From what you are saying, it is 1) an independent analysis by someone (in 2011? By whom?), 2) making assumptions about the 787-8s performance.

The analysis is done by Lissys, they are the developer of the aircraft performance package called Piano-X. Piano-X is used by both Boeing and Airbus, as well as many airlines and consultants.

This is the same link without the additional element for grammatical construction of a sentence.....

http://www.lissys.demon.co.uk/boeing787-2011.html



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 114, posted (1 year 9 months 3 weeks 4 days ago) and read 15865 times:

November 2011

All statements, models and assessments represent the independent opinions and analyses of Lissys. They do not imply any connection with, or approval by the manufacturer or any other organisation.


"Piano-X models constitute the best estimates of Lissys "

Ok got is Zeke. So everything is based on assumptions and on a model by Lissys in 2011. I am sure they will be updating their models as the real world data comes in.

The FCOMS (787 and 767) tell the story:

Quoting tdscanuck (Reply 48):
If we credit the 787-8 40,000 lbs and take it up to 460,000 lbs for approximately equal payload, the 787-8 still burns 10% less fuel per hour.

- While traveling 6% faster, simplifying, it means 6% less burn time over the trip, or an additional 6% trip fuel burn savings due to the extra speed. Total 16%. I know it's simplified, but shows just how far off the Lissys model is. Their model has the 787 with a total 1.8% trip fuel burn saving over the 767 on a long haul route.

For a typical mission carrying 22 metric tonnes over 5000 nm (roughly HND-FRA), the block fuel burn of the B787-8 is calculated to be 50.1 tonnes. This compares to 50.7 tonnes for the B767-300ERW...

This not only contradicts the FCOMS, but the various ANA statements, which is a public company.


User currently offlinebikerthai From United States of America, joined Apr 2010, 2011 posts, RR: 4
Reply 115, posted (1 year 9 months 3 weeks 3 days 23 hours ago) and read 15733 times:

Quoting zeke (Reply 113):
It is the natural log of the ratio of takeoff weight divided by the landing weight, and I was made in the context of short sectors.

  Do you mean max take off weight vs. max landing weight?

At first glance I interpreted this as the amount of fuel burned during a flight which is really overall performance and the result of which gives a lower value as more efficient.

If it was max take off vs max landing then I may need more time to digest what it means. . . if I can get my head around it.

Structural efficiency to me would be something like Max take-off or max landing weight vs empty weight.

bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 116, posted (1 year 9 months 3 weeks 3 days 23 hours ago) and read 15760 times:

How about we all wait to see what Al Baker at Qatar says about his 787 ... trust me , if ANA and JAL exaggerated performance ... we will hear about it. If he keeps quiet then lets all agree that ANA and JAL are probably right.

Btw ... this is the first thread I got a headache trying to decipher all the math haha , maybe this should be moved to the tech/ops forum.


User currently offlinelightsaber From United States of America, joined Jan 2005, 12420 posts, RR: 100
Reply 117, posted (1 year 9 months 3 weeks 3 days 21 hours ago) and read 15621 times:
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Quoting phxa340 (Reply 116):
How about we all wait to see what Al Baker at Qatar says about his 787 ... trust me , if ANA and JAL exaggerated performance ... we will hear about it. If he keeps quiet then lets all agree that ANA and JAL are probably right.

I agree with that methodology!   

Except, QR will compare to the A330, not the 767.   

But if the 788 does not meet Al Baker's expectations, there is no doubt he'll be vocal.

Lightsaber



I've posted how many times?!?
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 118, posted (1 year 9 months 3 weeks 3 days 20 hours ago) and read 15398 times:

Quoting bikerthai (Reply 115):

Quoting zeke (Reply 113):
It is the natural log of the ratio of takeoff weight divided by the landing weight, and I was made in the context of short sectors.

  Do you mean max take off weight vs. max landing weight?

No, he meant actual takeoff weight divided by actual landing weight. This is what goes into the Brueget range equation (the ratio comes from the integral that begets the equation).

However, this ratio is very mission specific, hence it's only properly referred to as structural efficiency when the airplane is being fully utilized (MTOW/MLW). If you're using any other numbers than that then the range equation is still valid but the ratio isn't measuring structural efficiency. Structural efficiency is an aircraft property that describes capability, not a variable parameter that changes with mission.

I think we all agree that there is some range below which the 767 has a trip fuel advantage for equal payload. The disagreement seems to be over what range that is...I think it's *way* smaller than many others seem to think it is, so small that it's talking about routes where one wouldn't typically use a 767 or 787.

Tom.


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 119, posted (1 year 9 months 3 weeks 3 days 19 hours ago) and read 15374 times:
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Quoting tdscanuck (Reply 118):
I think we all agree that there is some range below which the 767 has a trip fuel advantage for equal payload. The disagreement seems to be over what range that is...I think it's *way* smaller than many others seem to think it is, so small that it's talking about routes where one wouldn't typically use a 767 or 787.

The site that did the analysis between the 787-8 and 767-300ER on domestic Japanese operations noted that the 757-300 was the best choice for the mission from a fuel-burn perspective.  


User currently offlineikramerica From United States of America, joined May 2005, 21416 posts, RR: 60
Reply 120, posted (1 year 9 months 3 weeks 3 days 17 hours ago) and read 15148 times:

Quoting Stitch (Reply 119):
The site that did the analysis between the 787-8 and 767-300ER on domestic Japanese operations noted that the 757-300 was the best choice for the mission from a fuel-burn perspective.  

It was a lost opportunity that the Japanese and Chinese carriers didn't order 757-300s for at minimum the secondary short dense routes.



Of all the things to worry about... the Wookie has no pants.
User currently offlinesweair From Sweden, joined Nov 2011, 1806 posts, RR: 0
Reply 121, posted (1 year 9 months 3 weeks 3 days 10 hours ago) and read 14787 times:

But hey a new real 757 replacement might still find a lot of orders, conversions from other models.. I think the NSA will account for this as it will be bigger than the 737 base model.

Even the A319/737-700 size has very few orders now. I see the NBs growing upward and they should, there is a gap up to 788 for the future. The 767/A330 will not stay forever either.


User currently offlinebikerthai From United States of America, joined Apr 2010, 2011 posts, RR: 4
Reply 122, posted (1 year 9 months 3 weeks 3 days 7 hours ago) and read 14516 times:

Quoting tdscanuck (Reply 118):
However, this ratio is very mission specific,

Yeah, that's what I thought. Mission specific means that aerodynamic and engine efficiencies also comes in to play.

I was just thinking purely from a airframe "structures" stand point: "How much load you can carry and how much structure you need to take that load".

bt

[Edited 2012-06-29 06:23:43]


Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 123, posted (1 year 9 months 3 weeks 3 days ago) and read 14154 times:

Quoting zeke (Reply 113):
The structural efficiency I was referring to was in relation to the formula in reply 54.

Thanks for the correction and clarification, because the formula you posted in reply 54 is the Breguet Range Equation, not any definition of structural efficiency.

The structural efficiency of the 787 is virtually identical to the 767. For fun, some comparisons:

The 787-8 lifts the equivalent of 107% of its OEW
The 763ERW lifts the equivalent of 106% of its OEW
The A330-300 lifts the equivalent of 90% of its OEW
The A380 lifts the equivalent of 134% of its OEW
The 747-8i lifts the equivalent of 110% of its OEW

This does not speak to other very important metrics such as Zero fuel weights, Structural payloads, L/D, Engine SFC etc., that flow into the overall efficiency of each aircraft. This is clearly seen in the A330's overall low structural efficiency, which overall is a very good and efficient plane, certainly much better than the 767 over most routes, despite lifting a much smaller fraction of its OEW.

Quoting tdscanuck (Reply 118):

I think we all agree that there is some range below which the 767 has a trip fuel advantage for equal payload. The disagreement seems to be over what range that is...I think it's *way* smaller than many others seem to think it is, so small that it's talking about routes where one wouldn't typically use a 767 or 787.

I remember South West Airlines saying very worrying things about the weight gain of the 737-700 over the 737-300, which turned out to be a 12,000lb OEW increase, because they said the extra weight might not improve fuel efficiency on their short route structure. But we know Boeing did in fact make the 737-700 more efficient over almost all sectors, despite the large increase in weight.


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 124, posted (1 year 9 months 3 weeks 2 days 23 hours ago) and read 14018 times:

Quoting tdscanuck (Reply 118):

However, this ratio is very mission specific, hence it's only properly referred to as structural efficiency when the airplane is being fully utilized (MTOW/MLW). If you're using any other numbers than that then the range equation is still valid but the ratio isn't measuring structural efficiency. Structural efficiency is an aircraft property that describes capability, not a variable parameter that changes with mission.

That depends on where one if viewing the problem from. An operator already has an established network, and they may have a wish list of additional ports that could be added to that network. The range between those ports is fixed, and various alternates is known. The payload would also have a statistical basis, with an allowance for growth.

In many cases the the capability built into the aircraft far exceeds what is required, and the operator then elects to reduce the MTOW when the aircraft is used. If one tries to address the exercise as to what aircraft will give the greatest capacity over each route, everyone would be operating A380s over every sector, that however is not the constraint that is being optimized. What is being optimized is what aircraft carries the desired payload over a fixed range, so the structural efficiency for that route is really the only factor airlines have control over, it is their desired payload to be carried by a given airframe.

In reality operators elect not to use the full aircraft capability or MTOW almost every flight, this could be with a lower density cabin, less than 100% LF, less than 100% fuel load.

Quoting tdscanuck (Reply 118):

I think we all agree that there is some range below which the 767 has a trip fuel advantage for equal payload. The disagreement seems to be over what range that is...I think it's *way* smaller than many others seem to think it is, so small that it's talking about routes where one wouldn't typically use a 767 or 787.

That is a nice round about way of say that the 787 does not enjoy a fixed advantage over the 767 over all ranges, which is what I have been stating consistently.

Quoting Stitch (Reply 119):

The site that did the analysis between the 787-8 and 767-300ER on domestic Japanese operations noted that the 757-300 was the best choice for the mission from a fuel-burn perspective.

That is block fuel over those 3 types, if you are looking at a 25t payload, the A321 would be better still, it is just enough airframe to do that job over 1,000 nm. That is only one route, the airline would need to look at the overall network to see what suits them. I hear ANA will soon be using 787-8s domestically with an even higher density cabin, around 320 seats. In that configuration it will give narrow bodies a run for their money.

Quoting bikerthai (Reply 122):
I was just thinking purely from a airframe "structures" stand point: "How much load you can carry and how much structure you need to take that load".

That is how airlines think, what aircraft will carry a given payload over a given route best. This is lost on a lot of people on a.net, they think airlines shop around for what aircraft carries the most amount of payload furthermost.

Quoting tommytoyz (Reply 123):

Thanks for the correction and clarification, because the formula you posted in reply 54 is the Breguet Range Equation, not any definition of structural efficiency.

I am well aware of what the formula is, I posted it. It has three main components, which are conveniently labeled, aerodynamic efficiency, propulsive efficiency, and then structural efficiency.

Airlines do not go around flying their aircraft at MTOW all the time, we load enough fuel for the given route and payload. The range, speed, propulsive efficiency, and aerodynamic efficiency are not really factors airline have a lot of control over, payload is. On short sectors more than likely you would exceed maximum landing weight if you were to operate at MTOW anyway.

Quoting tommytoyz (Reply 123):
This is clearly seen in the A330's overall low structural efficiency, which overall is a very good and efficient plane, certainly much better than the 767 over most routes, despite lifting a much smaller fraction of its OEW.

A330s are efficient when used medium haul against the 767 and 777 because they are efficient at lifting the airlines desired payload over the airlines fixed points in their route structure. It is not uncommon for me to takeoff being MZFW limited, and landing just at MLW, and still have a lot of margin with MTOW as the range between the departure and destination is fixed. Airlines are not that concerned about how the aircraft performs at maximum range, or 100% load factors, airlines what to know how the aircraft perform with their projected payloads over the fixed points in the route structure.

It is so disconnected from reality to think airlines operate aircraft at 100% load factors, to their full range capacity, and at MTOW.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 125, posted (1 year 9 months 3 weeks 2 days 23 hours ago) and read 13993 times:

Quoting tdscanuck (Reply 118):
I think we all agree that there is some range below which the 767 has a trip fuel advantage for equal payload. The disagreement seems to be over what range that is...I think it's *way* smaller than many others seem to think it is, so small that it's talking about routes where one wouldn't typically use a 767 or 787.

Based on a 30t payload , a 788 OEW of 114.5 t. a 767 OEW of 93.032t the cross over point is right about 1000nm. According to PIANO-X the fuel burn for that sector distance , the 787 is 10.602t and the 767-300ER is 10.587t. At 1500nm it is 14.665t and 15.369t respectively.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 126, posted (1 year 9 months 3 weeks 2 days 23 hours ago) and read 13897 times:

Quoting zeke (Reply 124):
It is so disconnected from reality to think airlines operate aircraft at 100% load factors, to their full range capacity, and at MTOW.

I don't think anyone is thinking or saying that. Total structural efficiency is one thing, how airlines operate is another.

It will be interesting to see Lissys make substantial changes to their models regarding the 787. Everything I have seen indicates to me that they are way off target, at least as of late 2011. A 1.8% better block fuel burn over FRA HND carry similar payloads over the 763ERW is not a very credible calculation, IMHO.


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 127, posted (1 year 9 months 3 weeks 2 days 22 hours ago) and read 13902 times:

Quoting zeke (Reply 124):
What is being optimized is what aircraft carries the desired payload over a fixed range, so the structural efficiency for that route is really the only factor airlines have control over, it is their desired payload to be carried by a given airframe.

That's our disagreement...there's no such thing as "structural efficiency for that route". Structural efficiency is a measure of structural capability, not how much capability you're using. It's like claiming you have an "Mmo for a route". You have Mmo, and you have cruise speed for a route. They're not the same thing.

The weight term in the Brueget range equation only equals the structural efficiency if you are using MTOW. It get called "structural efficiency" because the most common use of the range equation is to calculate the maximum range given the other terms...you absolutely can use it to do other ranges but then the weight term no longer equals structural efficiency.

Quoting zeke (Reply 124):
That is a nice round about way of say that the 787 does not enjoy a fixed advantage over the 767 over all ranges, which is what I have been stating consistently.

You've also been constantly saying that the 787 doesn't beat the 767 on real world routes. That's what we disagree about. Please don't try to claim that I'm agreeing with you on this.

Quoting zeke (Reply 124):
It is so disconnected from reality to think airlines operate aircraft at 100% load factors, to their full range capacity, and at MTOW.

I agree, which is why nobody has been saying that. But if you want to actually calculate structural efficiency those are the numbers you have to use.

Quoting sunrisevalley (Reply 125):
Based on a 30t payload , a 788 OEW of 114.5 t. a 767 OEW of 93.032t the cross over point is right about 1000nm.

That sounds a little high to me but in the ballpark. So who's going to credibly argue that either the 767 or the 787 were designed to be doing


User currently offlineastuteman From United Kingdom, joined Jan 2005, 9836 posts, RR: 96
Reply 128, posted (1 year 9 months 3 weeks 2 days 22 hours ago) and read 13890 times:
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Quoting tommytoyz (Reply 123):
The A380 lifts the equivalent of 134% of its OEW

You'll pardon me having a damned good belly laugh at this one, Tommytoyz.
I can assure you it's not at your expense.   

After spending the thick end of half a decade having the structural inefficiency of the A380 rammed down my throat on A-net.......

Never thought I'd see this day..  

Rgds


User currently offlineFlighty From United States of America, joined Apr 2007, 8204 posts, RR: 3
Reply 129, posted (1 year 9 months 3 weeks 2 days 21 hours ago) and read 13862 times:

Quoting tdscanuck (Reply 127):
You've also been constantly saying that the 787 doesn't beat the 767 on real world routes. That's what we disagree about. Please don't try to claim that I'm agreeing with you on this.

It sounds like the 787 really does beat the 767 even with light loads (i.e., on a trip fuel basis). It is surprisingly difficult to get that information -- Boeing sales literature certainly isn't a big help. They are always quoting their favorite seat configurations, and then reporting seat-level numbers... which the media then mis-reports, because it's not like they can fully comprehend this.

But the plain truth of it is, the 787 seems to save a bit of fuel and carry a heavier load while doing so. Which is a great accomplishment.

The 748 vs 744 comparison is similar. The 748 is amazing, but it's larger, and the increase in size won't always be utilized. But it does save some fuel (0%? 3%?).


User currently offlinelightsaber From United States of America, joined Jan 2005, 12420 posts, RR: 100
Reply 130, posted (1 year 9 months 3 weeks 2 days 21 hours ago) and read 13846 times:
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Quoting SEPilot (Reply 47):
But a Gulfstream G650 would have much lower trip cost. What does that prove?

It proves one can afford a G650.   

  

Quoting ikramerica (Reply 120):
It was a lost opportunity that the Japanese and Chinese carriers didn't order 757-300s for at minimum the secondary short dense routes.

   However, the line is closed, so now we debate NEO vs. MAX.  
Quoting tdscanuck (Reply 127):
Quoting sunrisevalley (Reply 125):
Based on a 30t payload , a 788 OEW of 114.5 t. a 767 OEW of 93.032t the cross over point is right about 1000nm.

That sounds a little high to me but in the ballpark. So who's going to credibly argue that either the 767 or the 787 were designed to be doing

Anything less than 2000nm is likely to go to the MAX and NEO unless they are constrained runs such as in Japan. Widebody flights will be for runs that require 3000nm+ 'still air' range. At every narrowbody aircraft generation change, they have taken more and more of the market. I'm excited for the 787, but if we're debating the advantages of the 767 on short runs, as tdscanuck was alluded, we're not discussing the missions were either plane is optimal verus the upcomming re-engined narrowbodies.

Any airline not considering that competitive situation is being silly.

Lightsaber



I've posted how many times?!?
User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 131, posted (1 year 9 months 3 weeks 2 days 21 hours ago) and read 13769 times:

Quoting tdscanuck (Reply 127):
That sounds a little high to me but in the ballpark

You are right. Looking into the innards of the PIANO-X profile of the 788 they had a SFC factor of 1.02%. Change that to 1.0 and the cross over drops to 800nm; 8727kg for the 788 and 8734kg for the 767-300ER


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 132, posted (1 year 9 months 3 weeks 2 days 20 hours ago) and read 13716 times:

Quoting sunrisevalley (Reply 131):
Change that to 1.0 and the cross over drops to 800nm; 8727kg for the 788 and 8734kg for the 767-300ER

Just to make sure I fully understand what we're saying here, PIANO-X, the reference standard that everyone on a.net likes to use for these things, says that, for equal payload (an unrealistic situation that penalizes the 787) the 787-8 will burn less *trip* fuel than the 767-300ER on any flight over 800nm (~2 hrs).

Work the higher cruise speed, greater capability, and real-world load factors into that and the conclusion is that the 787-8 should be absolutely kicking the 767-300ER's ass. Which is exactly what the customers are saying it does. Which shouldn't surprise anyone, since that's what it was designed to do.

Thank you for checking the numbers!
Tom.


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 133, posted (1 year 9 months 3 weeks 2 days 20 hours ago) and read 13708 times:

Quoting tdscanuck (Reply 127):

That's our disagreement...there's no such thing as "structural efficiency for that route".

I beg to differ, that is how it is also described in textbooks, e.g. page 296 of "Elements of Aircraft Performance" http://mail.vssd.nl/hlf/ae02ch15.pdf

"The weight fraction Wb/Wto maybe regarded as the structural efficiency since the lighter the airplane is built, the greater the useful load fraction".

They then go on to compare two aircraft over the same fixed range, and compare their relative structural efficiency over that range. That is exactly what I have been doing here.

This thread is about how the 787 is doing in service over real routes in airline service, not what it can hypothetically do on paper at maximum range. Only two routes so far are over 5000 nm.

Quoting tdscanuck (Reply 127):
the weight term no longer equals structural efficiency.

That is not true, we are talking about in service aircraft.

Quoting tdscanuck (Reply 127):
You've also been constantly saying that the 787 doesn't beat the 767 on real world routes.

I have NEVER made that statement, that is a deliberate and gross misrepresentation of what I have said, the second time on this thread.

I have consistently said I do not believe the blanket statements being made.
  • I questioned the claims that the 787 was beating the 767 by around 20% in block fuel, I have shown how that blanket statement is not the case.
  • I questioned the claims that the 787 was beating the 767 by around 20% on a per seat basis, I have shown how that blanket statement is also not true.
  • I questioned the claims that the 787 was beating the 767 by a fixed fraction, this is also not true.


Can the 787 beat the 767 by 20% on block fuel basis over a route ? yes, does it always do so ? no.
Can the 787 beat the 767 by 20% on a per seat basis over a route ? yes, does it always do so ? no.
Can the 767 beat the 787 by 20% on block fuel basis over a route ? yes, does it always do so ? no.
Can the 767 beat the 787 by 20% on a per seat basis over a route ? yes, does it always do so ? no.

The reason why it does not always do so is that the length of the route, payload, and seating configurations can vary significantly, this is consistent with what I stated above. The whole premise of using extreme data points does not show anything. For example ANA plan to have 788s with configurations between 158 and 335 seats. When comparing them to the 763, obviously fuel burn per seat will vary significantly, comparing a 335 seat 788 to a 204 seat 763, and 216 seat 763 to a 158 seat 788 will produce very different results, neither being incorrect. Likewise for routes, are they using a 220 nm HND-ITM route, or a 5100 nm NRT-FRA ?

Quoting zeke (Reply 54):
I do not believe the 787 enjoys a fixed fraction improvement over any aircraft, including the 767. The reason being is the number of variables involved.
Quoting zeke (Reply 54):
This means one should expect the relative performance advantage to change with range and payload.
Quoting zeke (Reply 69):
One would expect the advantages to increase with range, the 787-8 is a ULH machine. When used domestically or on the shorter international flights, I do not think they are "massively more fuel efficient".

Lissys put that succinctly in their analysis

"The factual significance and operational reality of such (counter-expectational) mission-specific fuel burns can appear negated or reversed through contrived definitions of efficiency metrics based on point conditions."

And Boeing has qualified the conditions they made the claim over, it is a point condition, not over all ranges and payloads
"Boeing long range interior rules (3-class), results in 242 in the 787 and 218 in the 767.
Full pax & bags at (not sure, but probably 95kg/pax) and no rev cargo.
6,000nm"

I have been consist making this comments over short sectors where the 767 being lighter should be performing better.

Quoting tdscanuck (Reply 127):
Please don't try to claim that I'm agreeing with you on this.

You already have i.e.

Quoting tdscanuck (Reply 48):
But, at Zeke correctly points out, the 787-8 weights more so, with equal payload, the gross weight will be more. If we credit the 787-8 40,000 lbs and take it up to 460,000 lbs for approximately equal payload, the 787-8 still burns 10% less fuel per hour.
Quoting tdscanuck (Reply 118):

I think we all agree that there is some range below which the 767 has a trip fuel advantage for equal payload.
Quoting tdscanuck (Reply 127):
But if you want to actually calculate structural efficiency those are the numbers you have to use.


We are not talking about maximum range, we are talking about fixed sector lengths with various airline specific interior configurations. Time to move on what is theoretically possible into the realm of what is actually happening. That is what this thread is about, actual in service results for the 787.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 134, posted (1 year 9 months 3 weeks 2 days 19 hours ago) and read 13622 times:

Quoting zeke (Reply 133):
I beg to differ, that is how it is also described in textbooks, e.g. page 296 of "Elements of Aircraft Performance" http://mail.vssd.nl/hlf/ae02ch15.pdf

They talk about structural efficiency, correctly, in relation to *maximum total range* (their words, not mine). They go on to compare equal state lengths for different aircraft by weight fraction. Nowhere do they claim (correctly) that structural efficiency is something calculated at other than max weight.

Quoting zeke (Reply 133):
They then go on to compare two aircraft over the same fixed range, and compare their relative structural efficiency over that range.

No, they compare weight ratio. As they should. As you should too.

Quoting zeke (Reply 133):
This thread is about how the 787 is doing in service over real routes in airline service

Yes. The customers are saying it's beating the 767 by ~20% in real routes in airline service. The data bears this out for the routes they're actually running.

Quoting zeke (Reply 133):
I questioned the claims that the 787 was beating the 767 by around 20% in block fuel, I have shown how that blanket statement is not the case.

Nobody made the blanket statement that it beats the 767 by 20% all the time. That's a straw man. The customers, and Boeing, and PIANO-X, all claim that it beats the 767 by 20% at various point conditions and the data bears that out.

Quoting zeke (Reply 133):
I questioned the claims that the 787 was beating the 767 by around 20% on a per seat basis, I have shown how that blanket statement is also not true.

Nobody made the blanket statement that it beats the 767 by 20% all the time. See above.

Quoting zeke (Reply 133):
I questioned the claims that the 787 was beating the 767 by a fixed fraction, this is also not true.

Nobody made the blanket statement that it beats the 767 by a fixed fraction all the time. See above.

Quoting zeke (Reply 133):
Can the 767 beat the 787 by 20% on block fuel basis over a route ? yes,

What route that's actually within the real world service of the 767? After all, you want to work with real world data and, according to the data here (which nobody's disputed so far), the crossover point for the 767 to burn less block fuel than the 787-8 (at equal payload, which isn't real world) is below 800nm.

Quoting zeke (Reply 133):
Can the 767 beat the 787 by 20% on a per seat basis over a route ? yes

What route? Same arguments as above.

Quoting zeke (Reply 133):
And Boeing has qualified the conditions they made the claim over, it is a point condition, not over all ranges and payloads

Of course it's a point condition. Boeing aren't idiots; if you give a single number it's got to be a point condition.

Tom.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 135, posted (1 year 9 months 3 weeks 2 days 18 hours ago) and read 13568 times:

Quoting zeke (Reply 133):
I have consistently said I do not believe the blanket statements being made.

Nobody has made blanket statements. I have asked you for links to any and you have not been able to provide any to "blanket statements". Vague statements have been made, yes, claiming a vague 20%. But a vague statement does not lead anyone to conclude that the speaker meant to say the 787 is beating the 767 by a fixed fraction on all routes. Anyone in aviation knows no plane has a fixed fraction fuel burn delta or cost delta Vs. any plane on all routes. Nobody has said this about the 787. Again, please link to one if I am wrong.

It's interesting, you see something that is not there and then you debate it.

Quoting tdscanuck (Reply 127):
there's no such thing as "structural efficiency for that route".

This is only logical. The SFC doesn't change, nor does the L/D, the wingspan and neither does the structural efficiency. The structural efficiency is a static number. On anything less than max weights, you are describing a fractional structural efficiency of the aircraft. We might as well talk about power settings "for that route", rather than the max thrust of the engines at sea level to compare the power of the engines.

But now, after many clarification posts, I understand what you meant under "structural efficiency for that route", which for sure is different from "structural efficiency" - which is the term you used originally.

For further clarity, let's see some numbers. You have stated that the 787 has poor "structural efficiency for that route" , as you say, over short ranges Vs the 767. Can you give some numbers and examples with the assumptions, so we can all see just how poor?

[Edited 2012-06-29 18:40:35]

User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 136, posted (1 year 9 months 3 weeks 2 days 18 hours ago) and read 13539 times:

Quoting tdscanuck (Reply 134):
They talk about structural efficiency, correctly, in relation to *maximum total range* (their words, not mine).

That term is used once in the entire chapter. Try reading section "15.5 Weight breakdown" where weight is discussed in detail and it is NOT confined to "maximum total range".

Quoting tdscanuck (Reply 134):
Nowhere do they claim (correctly) that structural efficiency is something calculated at other than max weight.

In section 15.5is where they talk about structural efficiency, "The weight fraction Wb/Wto maybe regarded as the structural efficiency since the lighter the airplane is built, the greater the useful load fraction".

Wto is defined in equation (15.40), it is a variable number as it includes the Wp - payload, and Wf - trip fuel. They then go on to describe it in words clearly "The total weight is the weight at takeoff breake release (TOW), and depends on the loading condition.", Wb defied as the OEW.

Quoting tdscanuck (Reply 134):

Yes. The customers are saying it's beating the 767 by ~20% in real routes in airline service. The data bears this out for the routes they're actually running.

I would suggest you read what they actually said, not what you think they said. They also have not specified any route in particular.

Quoting tdscanuck (Reply 134):

Nobody made the blanket statement that it beats the 767 by 20% all the time.

From the ANA press release http://www.ana.co.jp/pr/12_0406/12-035.html

"Fuel consumption of the 787, as predicted effects of the Boeing was originally are expected to decline 20% in the comparison machine with existing (machine type B767), of about 21% higher than expected in comparison after actual operation we have achieved the reduction. "

from http://www.marketwatch.com/story/all...-international-capacity-2012-06-10

"As the launch customer of the Boeing 787 Dreamliner, ANA took delivery of the first of its 55 B787s on order in last September, and is now operating seven of the aircraft on domestic flights and one on an international route between Tokyo Haneda and Frankfurt. Mr. Ito said the 787 twinjets, which carry around 220 to 250 passengers, help the airline save around 21% of fuel consumption on each flight. "

Quoting tdscanuck (Reply 134):

What route that's actually within the real world service of the 767?

The shortest route they are using the 767 and 787 on is just 220 nm (HND-ITM)

Quoting tdscanuck (Reply 134):
the crossover point for the 767 to burn less block fuel than the 787-8 (at equal payload, which isn't real world) is below 800nm.

A little over half of the current routes are around 800 nm or less HND-ITM, HND-HIJ, HND-OKA, HND-UBJ, HND-FUK, HND-KOJ, HND-MYJ, they average to around 450 nm.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinefrmrCapCadet From United States of America, joined May 2008, 1690 posts, RR: 1
Reply 137, posted (1 year 9 months 3 weeks 2 days 16 hours ago) and read 13383 times:

Actually their is a more interesting possible thread other than the rehashes we are seeing on this thread. What specific routes, payloads, missions will the various 330s, 767s, and (even) 747s do better than mature 350s and 787s. And if the used price is low are their other routes and etc.

[Edited 2012-06-29 20:44:17]


Buffet: the airline business...has eaten up capital...like..no other (business)
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 138, posted (1 year 9 months 3 weeks 2 days 14 hours ago) and read 13213 times:

Zeke, enough words. Numbers please - as you define "structural efficiency for that route" (short routes) 787 Vs 767. What are your numbers in regards to structural efficiency on any route for the two, as you define them?....Thank you.

User currently offlineWarmNuts From United States of America, joined May 2006, 94 posts, RR: 4
Reply 139, posted (1 year 9 months 3 weeks 2 days 3 hours ago) and read 12701 times:

This has been an engaging thread, wholly informative, even if lacking in elucidation.  

Regarding the quasi-qualified metric put forth by ANA (read that thread) that obviously served (at least in large part) as the basis for this article:

Quoting zeke (Reply 81):
That being said, the blanket statement of X% "better than expected" I cannot agree with, as the maths does not back those numbers up. The statement is too simplistic for a complex problem with so many variables.

   Well, kinda-  . While the statement is most definitely an over-simplification absent any of the qualified or quantifiable metrics by which such a measurement was derived, the statement's intended audience is customers and shareholders more so than analysts.

Amazingly, I don't see anywhere in this colossal thread (or the last, at least as far as I can recall) that addressed the very simple explanation that the "x% better" metric might represent a leveraged average across the route network on which ANA has deployed the 787.

This seems to be a simple explanation that would qualify their reported findings, and would allow for both Tom's knowledge and Zeke's analysis to both be correct.

Quoting zeke (Reply 103):
However it has been reported they they are enjoying a fixed fraction advantage on EVERY flight, the 787-8 is worse than the 767 on these sectors.

Careful now. I don't see in the original press release where ANA states it enjoys a fixed advantage on every flight:

As per the press release: "ANA is pleased to confirm that the saving amounts to 21% per flight"

Once again, it would seem entire reasonable to suggest that the "per flight" qualifier may refer to a leveraged average. This would account for the phrasing of the statement.

Quoting zeke (Reply 133):
Quoting tdscanuck (Reply 127):

That's our disagreement...there's no such thing as "structural efficiency for that route".

I beg to differ, that is how it is also described in textbooks, e.g. page 296 of "Elements of Aircraft Performance" http://mail.vssd.nl/hlf/ae02ch15.pdf

I guess I should have figured that framed piece of paper on the wall stating something about having a degree in mathematics would come into use here sooner or later. From the above linked-to text:

Quoting page 296, Elements of Aircraft Performance]"The weight fraction Wb/Wto may be regarded as the structural efficiency since the lighter the airplane is built, the greater is the useful load fraction."[/quote]

Where Wb is the empty weight (i.e., no payload or fuel), and Wto is the total weight, defined in the text as Wb + payload (Wp) + fuel (Wf) + fuel reserves (Wfr), giving us Wto=Wb+Wp+Wf+Wfr.

In the preceding sentence, the text states:

Quoting page 296, Elements of Aircraft Performance:
"Equations (15.45) and (15.44) show that the aim is obviously to make the range factor as large as possible and to keep the fraction Wb / Wto low in order to obtain a large payload fraction."

This seems to state that - at least what this text defines as structural integrity - is dependent on the payload (and fuel) fractions by which Wto is derived, i.e., operastor-dependent variables that would, as per the above equation, directly impact the total weight, and thus the "structural integrity" as defined in the above-referenced text.

In Zeke's defense (not that he needs it - to the contrary he most certainly does not!), nowhere do I see block length, i.e., maximum total range, listed as a component of that variability.

[quote=tdscanuck (Reply 134):
They talk about structural efficiency, correctly, in relation to *maximum total range* (their words, not mine). They go on to compare equal state lengths for different aircraft by weight fraction. Nowhere do they claim (correctly) that structural efficiency is something calculated at other than max weight.

As per the above, I do not see where the quantified metric of MTOW is inextricably linked to the equation by which structural efficiency is defined, at least as per the definition of the term in the above text.

However, the above text does absolutely define structural efficiency as a measure of capability and not performance, as you state your easlier post.

Thus, the use of Wb/Wto is IMO wholly irrelevant when compared to the measured performance by the operator(s).

It is one issue to question whether or not the measured performance falls outside of the measured capability - and I think that is kind of the gist of what is being discussed here - but I was rasied not to hang a horse thief for murder.

In other words, if performance falls outside of a defined theoretical capability, I would think it wise to visit the defined parameters used to detemine capability (if not he model by which capability was measured) rather than dismissing validity of the measured performance.

Pardon the poor formatting of the above - some parts of my post appear as a quote when not intended to and made the post more difficult to read...


User currently onlinemham001 From United States of America, joined Feb 2005, 3389 posts, RR: 2
Reply 140, posted (1 year 9 months 3 weeks 2 days 2 hours ago) and read 12636 times:

Quoting zeke (Reply 133):
Likewise for routes, are they using a 220 nm HND-ITM route, or a 5100 nm NRT-FRA ?
Quoting zeke (Reply 136):
from http://www.marketwatch.com/story/all...-international-capacity-2012-06-10

"As the launch customer of the Boeing 787 Dreamliner, ANA took delivery of the first of its 55 B787s on order in last September, and is now operating seven of the aircraft on domestic flights and one on an international route between Tokyo Haneda and Frankfurt. Mr. Ito said the 787 twinjets, which carry around 220 to 250 passengers, help the airline save around 21% of fuel consumption on each flight. "

Sheesh, are you still at this?
You know full well from the last thread that in another interview, he states "international" flights.


User currently offlineJAAlbert From United States of America, joined Jan 2006, 1491 posts, RR: 1
Reply 141, posted (1 year 9 months 3 weeks 1 day 21 hours ago) and read 12390 times:

Quoting WarmNuts (Reply 139):
This has been an engaging thread, wholly informative, even if lacking in elucidation.

Hey, great word, "elucidation"! I love it.

I have to say, for the most part, this thread might as well have been in Greek. The factors, ratios, and calculations bantered about make no sense to a person such as myself who can barely operate a desk calculator. That being said, it seems to me that if ANA is saying its getting some good mileage from its spanking new planes that something positive (fuel saving wise) must be happening. If ANA saw little or no improvement over its 767s, the press release would have said something to the effect that its lawyers are preparing for a rather important meeting with Boeing concerning compensation and damages.

It also seems to me that - after all the production snafus -- the 787 actually is doing what Boeing said it would do. That must be extremely gratifying to the Boeing folks who've toiled over the plane the past several years as well to as the current and future operators of the craft.


User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 142, posted (1 year 9 months 3 weeks 1 day 17 hours ago) and read 12244 times:

Quoting tommytoyz (Reply 138):
What are your numbers in regards to structural efficiency on any route for the two, as you define them?

I do not work for ANA or JAL, you would need someone from those airlines to tell you, they have their payload figures and planning rules.

Where I work, the process takes months with around half a dozen people working on it, it is not something I could do at home by myself. For me to do do some of the analysis at home, I would need purchase Piano 5, and I am not going to spend around US$100,000 for a license to just do one part of the analysis for your amusement. The tools required to to the analysis are not cheap.

When we looked at the 787, we also looked at the A330, A350 and 777 at the same time across the network. The resulting report has a NVP figure for each route, for each type (e.g A330-200 A330-300), and a number of different cabin configurations/products. A lot of work is put into it, I think for us it was a few hundred thousand different runs for our network with all the different types and configurations. It is a planning decision that will probably go forward the best part of 20 years. Being a long term model, we do not use new aircraft performance figures, we apply performance degradation consistent with what we have seen in the past across our other fleets and use our planning rules, we typically cannot achieve the OEMs range/payload that they publish publicly. One would therefore expect a new aircraft to do better than the model.

I would expect that ANA and JAL would have done similar analysis across their network, and this I think would have formed the basis of their expectations for the 787. They may have also run their model against a 767 seating configuration which are not in service as well, i.e. the same cabin product that is on the 787.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineferpe From France, joined Nov 2010, 2792 posts, RR: 59
Reply 143, posted (1 year 9 months 3 weeks 1 day 12 hours ago) and read 11989 times:

Quoting sunrisevalley (Reply 131):
You are right. Looking into the innards of the PIANO-X profile of the 788 they had a SFC factor of 1.02%. Change that to 1.0 and the cross over drops to 800nm; 8727kg for the 788 and 8734kg for the 767-300ER
Quoting tdscanuck (Reply 132):
Just to make sure I fully understand what we're saying here, PIANO-X, the reference standard that everyone on a.net likes to use for these things, says that, for equal payload (an unrealistic situation that penalizes the 787) the 787-8 will burn less *trip* fuel than the 767-300ER on any flight over 800nm (~2 hrs).

It is not a "reference standard", it is the best model of real world conditions available for free to everyone. The fact that a more adjustable version (Piano 5) is used by B, A, Airlines, Consultants, Analysts means it is useful when used with a bit of insight such as checking the basic assumptions (at leas on parts which are highlighted in the UI and are adjustable for everyone).

Lissys presented the latest assessment of the 787 in Nov 2011, at that time only 1 (or was it 2) frames where flying for ANA. It was common knowledge that the OEW for the first year of production was some 6t at least over original spec and that the engines were some 2% below spec as well. That is what Lissys put in the model for everyone to change as they see fit as the production standard progressed.

So run the 787 vs 767 analysis with the OEW that corresponds to your seating arrangement and the line number and engine PIP and you will get values pretty close to reality. It is not Piano-X which is the problem, it is the people who are criticizing it, yet so lazy to not even look into what it is (let alone changing the basic parameters such as OEW or TSFC to the analysis at hand).

Quoting tommytoyz (Reply 123):

The 787-8 lifts the equivalent of 107% of its OEW
The 763ERW lifts the equivalent of 106% of its OEW
The A330-300 lifts the equivalent of 90% of its OEW
The A380 lifts the equivalent of 134% of its OEW
The 747-8i lifts the equivalent of 110% of its OEW

Only 2 of these ratios are close to reality, you make very blanket statements with very little research. The Wiki 787-8 OEW has been wrong since I enter A.net a couple of years ago (and it has been pointed out a zillion times since), even Boeing has publicized a better figure in their ACAPs. If we use Boeing figures and adjust to a 242 cabin we are at 100%, if do not we are at 104%. How your got the 380 figure only you know.

[Edited 2012-07-01 00:57:40]


Non French in France
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 144, posted (1 year 9 months 3 weeks 16 hours ago) and read 11469 times:

Quoting zeke (Reply 142):
I do not work for ANA or JAL, you would need someone from those airlines to tell you, they have their payload figures and planning rules.
Quoting zeke (Reply 103):
I actually stated above that the 787 has the advantage with L/D and engines, but it not as structurally efficient.

Glad you cleared that up. In summary, you don't know how the 787 compares against the 767 by your definition of structural efficiency. I really wonder then what your point has been all along in arguing this exact point.

Relying on Lyssis, their models and Piano-x is folly at this point in regards to the 787 performance, as the 787 has way better fuel burn vs. the 767 than they predict. The 787 is much better than 1.8% in trip fuel burn against the 767 over the long haul HND-FRA route, not just by a little.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 6
Reply 145, posted (1 year 9 months 3 weeks 16 hours ago) and read 11465 times:

Quoting ferpe (Reply 143):
How your got the 380 figure only you know.

Wiki figures and I clearly said my numbers were only as accurate as these. If they are wrong, well, then so are the calculations. The more important point I wanted to make, is that despite large variations in structural efficiencies, it was not the dominating factor over how economical the overall aircraft were.

The 767 for instance is more efficient in this calculation than the A330. But the A330 is certainly much more efficient regardless. We can split hairs as to what the real and more accurate figures are, but that wasn't my point.


User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 146, posted (1 year 9 months 3 weeks 16 hours ago) and read 11433 times:

Quoting ferpe (Reply 143):
used by B, A, Airlines, Consultants, Analysts means it is useful when used with a bit of insight such as checking the basic assumptions (at leas on parts which are highlighted in the UI and are adjustable for everyone).

True, but notable omissions off their published customer lists are ironically JL and NH, the 2 companies who know the ACTUAL fuel burn savings.

They have stated that the planes are exceeding the original spec expectations. Why many members on here are going to extreme albeit creative lengths to disprove a claim from a publically traded company (Which can get into big trouble if they lie about performance btw) is beyond me.

Of course the A330 and 767 will do better than the 787 on certain routes. Every aircraft has a sweet spot. Just like a court ruling, every side can always claim victory by ignoring or focusing on certain sentences - since aircraft efficiency can be measured in so many different, lets just live it at NH and JL seemed very pleased.


User currently offlineferpe From France, joined Nov 2010, 2792 posts, RR: 59
Reply 147, posted (1 year 9 months 3 weeks 15 hours ago) and read 11378 times:

Quoting tommytoyz (Reply 145):
Wiki figures and I clearly said my numbers were only as accurate as these.

Then read your post again, just a blanket statement with no caveat about your sources.

Quoting phxa340 (Reply 146):
True, but notable omissions off their published customer lists are ironically JL and NH, the 2 companies who know the ACTUAL fuel burn savings.

They have stated that the planes are exceeding the original spec expectations. Why many members on here are going to extreme albeit creative lengths to disprove a claim from a publically traded company (Which can get into big trouble if they lie about performance btw) is beyond me.

He did not disproved the claim, he questioned all those that took it as a general truth and asked under what conditions, which is the correct way to handle such simplified press statements.



Non French in France
User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 148, posted (1 year 9 months 3 weeks 14 hours ago) and read 11389 times:
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Regardless of by how much the true figure is, the big takeaway here is that the 787 is better than the two airlines who operate them expected.

This must be putting smiles on the faces of management not only at All Nippon and Japan Airlines, but also Air India, Qatar Airways, Ethiopian, LAN, United, LOT Polish Airlines, Hainan and China Southern. And probably a grimace on the folks at Qantas.  Silly

And now we're starting to see airlines order 787s as opposed to canceling them.  bigthumbsup 

[Edited 2012-07-01 22:43:51]

User currently offlineferpe From France, joined Nov 2010, 2792 posts, RR: 59
Reply 149, posted (1 year 9 months 3 weeks 13 hours ago) and read 11256 times:

Quoting Stitch (Reply 148):
Regardless of by how much the true figure is, the big takeaway here is that the 787 is better than the two airlines who operate them expected.

It is great that there are good news for the 787 program, not only for the customers who ordered the aircraft in faith with Boeing but also for all those people in the extended 787 program who worked their butt of to live up to that image and to minimize the bad start that top management caused. Kudos to that 787 team    !



Non French in France
User currently offlinesunrisevalley From Canada, joined Jul 2004, 4614 posts, RR: 5
Reply 150, posted (1 year 9 months 3 weeks 7 hours ago) and read 10988 times:

Quoting tommytoyz (Reply 144):
Relying on Lyssis, their models and Piano-x is folly at this point in regards to the 787 performance, as the 787 has way better fuel burn vs. the 767 than they predict. The 787 is much better than 1.8% in trip fuel burn against the 767 over the long haul HND-FRA route, not just by a little

I am not sure where you are getting the information that PIANO-X is saying that the 787 trip fuel is 1.8% better than the 767 on an about 5000nm sector. Based on the parameters that I used in Rely 125 and 131 the 787 has better than 11% less fuel burn. The caveat is that without ANA's fleet specific 767 OEW's it is impossible to be more precise. It is my view that the quoted 20% is closer to the advantage the 788 would have over the 77E.But that is not what they are reported to have said.


User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 151, posted (1 year 9 months 3 weeks 7 hours ago) and read 10963 times:

Quoting ferpe (Reply 147):
He did not disproved the claim, he questioned all those that took it as a general truth and asked under what conditions, which is the correct way to handle such simplified press statements.

Which brings up my confusion , when the A380 beat fuel consumption expectations, some of these same A-Net members took the press releases as truth but now that the 787 has done this (Albeit beat expectations based on revised numbers) we must question the accuracy of the reports and back it up with hypothetical scenarios and numbers.  


User currently offlineStitch From United States of America, joined Jul 2005, 29686 posts, RR: 84
Reply 152, posted (1 year 9 months 3 weeks 6 hours ago) and read 10962 times:
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Quoting sunrisevalley (Reply 150):
I am not sure where you are getting the information that PIANO-X is saying that the 787 trip fuel is 1.8% better than the 767 on an about 5000nm sector.
http://www.lissys.demon.co.uk/boeing787-2011.html

Quote:
For a typical mission carrying 22 metric tonnes over 5000 nm (roughly HND-FRA), the block fuel burn of the B787-8 is calculated to be 50.1 tonnes. This compares to 50.7 tonnes for the B767-300ERW based on nominal performance (no in-service deterioration) and common reserve-rule assumptions that can be accessed via the models.


User currently offlineferpe From France, joined Nov 2010, 2792 posts, RR: 59
Reply 153, posted (1 year 9 months 3 weeks 4 hours ago) and read 10782 times:

Quoting phxa340 (Reply 151):
when the A380 beat fuel consumption expectations, some of these same A-Net members took the press releases as truth

I have read those threads, the A380 beat it's own cruise fuel burn expectations according to A, having been revised downwards by a missed OEW it was compensated by better then expected cruise L/D. One can discuss that statement but there are not to many variables in it.

The ANA press quote is quite different, here the full ANA press release re fuel burn once again:
"ANA today separately announces that the 787 has exceeded expectations in terms of fuel efficiency. At launch, it was anticipated that the 787 would save 20% in fuel for each international flight, but ANA is pleased to confirm that the saving amounts to 21% per flight. In the 6 months since ANA’s first 787 flight, this saving equates to around 5,000 kiloliters of fuel compared with the 767, or the equivalent of the fuel used for the Tokyo-Frankfurt route over one month. "

No definition of compared to what and no definition of the flights other then "international". As Zeke knew fully well ANAs route structure (he flies the same Asian skies as many of them) this "savings over what" and "international" needed dissecting. I find this fully OK and healthy.

[Edited 2012-07-02 09:11:25]


Non French in France
User currently offlinezeke From Hong Kong, joined Dec 2006, 8643 posts, RR: 75
Reply 154, posted (1 year 9 months 3 weeks 4 hours ago) and read 10754 times:

Quoting tommytoyz (Reply 144):
In summary, you don't know how the 787 compares against the 767 by your definition of structural efficiency.

I freely admit I do not know the EXACT numbers, nor do you, and I would dare say no one on this thread does. I have however given you enough information on this thread to work out some representative numbers, they will not be the actual numbers (one would need to work for the airline to get their payload numbers and have their fuel planning rules), however they should clearly show the trend. And the trend in my view raises enough doubt being made in some of the statements that were made.

In reply 54, I calculated some representative payloads, for various ANA configurations. Lissys has done the rest for you, they have worked out the OEW and fuel burns. You can add the numbers up to calculate the ratio. It will only tell you what I already know, the lighter aircraft is better.

Quoting tommytoyz (Reply 144):
The 787 is much better than 1.8% in trip fuel burn against the 767 over the long haul HND-FRA route, not just by a little.

I would not dispute that, however have you done your homework regarding this route ?

ANA as far as we have been able to work out has never operated the 767 over the HND-FRA route. The longest routes they operated 767s over from what I can tell are around 1000 nm less than that, like to the west coast of the USA. The aircraft type the 787 is replacing on the Frankfurt route is the 777, not 767.

The international route that ANA have been operating the 787 and 767 over is HND-PEK, that is around 1200 nm. Lissys did they analysis over 1000 nm and showed almost identical trip fuel. Now if the trip fuel is almost exactly the same, the only other variable that will produce the 21% reduction in fuel per seat, is by having around 20% more seats in the 787 compared to the 767. It is a matter of record that such a ratio exists between the early ANA 787s and their 767s.

Quoting tommytoyz (Reply 145):
The 767 for instance is more efficient in this calculation than the A330. But the A330 is certainly much more efficient regardless.

You have missed the point, going back and looking at the maximum payload numbers I worked out for various ANA 767 and 787 configurations :

Quoting zeke (Reply 54):
Looking at the combined passengers and cargo
787 156 seats = 34320 lb (passengers) 32130 lb (cargo) = 66450 lb
787 264 seats = 58080 lb (passengers) 26010 lb (cargo) = 84090 lb
767 216 seats = 47520 lb (passengers) 20880 lb (cargo) = 68400 lb

On shorter sectors where the Lissys analysis shows there is very little between the trips fuel values, the 767 is more efficient shorter distances as it has a lighter OEW. It is possible for a full 767 to have a zero fuel weight almost equal to the empty weight of the international configuration (158 seat) 787. I would not agree with any blanket statement that says the "A330 is certainly much more efficient regardless".

Quoting phxa340 (Reply 146):
They have stated that the planes are exceeding the original spec expectations.

They have not said that.

Quoting phxa340 (Reply 146):

Of course the A330 and 767 will do better than the 787 on certain routes.

The additional element missing from that sentence is payload. ANA said they getting these results on each flight, and those sector lengths vary considerably.

Quoting Stitch (Reply 148):
Regardless of by how much the true figure is, the big takeaway here is that the 787 is better than the two airlines who operate them expected.

I outlined above in reply 142 how an airline would build their expectations for a new type over a network.

An airline would not expect any two airframes coming off the production line to have the same mass, cg location, nor would they expect to see the engine and fuel flow parameters to be exactly the same between engines. Being an expensive item, the asset is expected to be in service for a long period of time. An airline would assume a level of engine performance degradation and airframe deterioration consistent with that they have been able to achieve historically on other types.

To get an idea of how this data is collected and used, have a look for a document called "Getting to Grips with Aircraft Performance Monitoring" on the internet.

Quoting sunrisevalley (Reply 150):
I am not sure where you are getting the information that PIANO-X is saying that the 787 trip fuel is 1.8% better than the 767 on an about 5000nm sector. Based on the parameters that I used in Rely 125 and 131 the 787 has better than 11% less fuel burn.

The Lissys analysis is for the same payload of a given range of a 787-8 vs a 767-300ER with winglets, according to the information in reply 92, Boeing was always talking about more seats in the 787 vs the 767 (I assume no winglets). This means they were looking at more payload in the 787, which is its strength, more payload over a greater range.

Quoting CM (Reply 92):
The Boeing claim of the 787-8 delivering 20% lower fuel burn per seat versus the 767-300ER is per the following rules:


Boeing long range interior rules (3-class), results in 242 in the 787 and 218 in the 767.
Full pax & bags at (not sure, but probably 95kg/pax) and no rev cargo.
6,000nm (which is FVL for the 767)



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinephxa340 From United States of America, joined Mar 2012, 832 posts, RR: 1
Reply 155, posted (1 year 9 months 3 weeks 4 hours ago) and read 10694 times:

Quoting zeke (Reply 154):
They have not said that.

Yes they did.

"After its first six months of service, ANA says the 787 efficiency levels are slightly up on the 20% savings originally expected at the beginning of the program"

http://www.aviationweek.com/Article....l/avd_06_26_2012_p01-01-470896.xml

Quoting zeke (Reply 154):
The additional element missing from that sentence is payload. ANA said they getting these results on each flight, and those sector lengths vary considerably.

Right but so far your main arguments has been in applying the performance of the 767 v 787 on short range missions. The 787 was never designed for optimal short range performance. The fact is , no one , except a few members on this thread that can't disclose the information anyways, knows the exact numbers. You are guessing based on available facts your are pulling from the web , some using estimations from 2011.