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ElroyJetson
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787 Fuel Efficency.

Mon Jan 27, 2020 3:55 pm

I recently read a great book on the development of the 787. The book is [i]The Birth of the 787 Dreamliner[i][by Edgar Turner.

Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763. As I recall, when ANA introduced the 788 on their NRT-CDG route they claimed a 21% fuel burn improvement versus their 763 ER.

The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.

My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient. That seems a little high to me as the A330 CEO is obviously newer tech than the 767.

Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family?


Thanks.
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PPVRA
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 4:27 pm

First flight of the 767 and A330 were "only" 11 years apart. Hence not a very large difference tech-wise.
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WIederling
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 5:23 pm

ElroyJetson wrote:
I recently read a great book on the development of the 787. The book is [i]The Birth of the 787 Dreamliner[i][by Edgar Turner.

Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763. As I recall, when ANA introduced the 788 on their NRT-CDG route they claimed a 21% fuel burn improvement versus their 763 ER.

The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.

My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient. That seems a little high to me as the A330 CEO is obviously newer tech than the 767.

Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family?


"The remaining 9% improvement is not specifically mentioned. "
Scaling gains, denser seatmap,
788 is slightly smaller than an A330-200
IMU the A330-200 took 6% more fuel for 12% more pax/payload ( fallout from the tanker wars.)


"Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family? "

More like 8% ( At least that is what Leeham got from asking fleet managers back then.)
Murphy is an optimist
 
WIederling
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 5:25 pm

PPVRA wrote:
First flight of the 767 and A330 were "only" 11 years apart. Hence not a very large difference tech-wise.


Tech wise they much further apart.
Murphy is an optimist
 
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zeke
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 5:28 pm

ElroyJetson wrote:
Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763.


That was fuel burn per seat, a key parameter was a high density cabin to achieve that.

Longhauler posted this years ago on a similar thread regarding real performance on the AC 787 and 767.

“The B767-300 carried 211 passengers at FL370/390, from LHR-YYZ in 7:28 ... fuel burn was 37,800 Kgs.
The B787-8 carried 251 passengers at FL380/400 from YYZ-ZRH in 7:22 ... fuel burn was 34,200 Kgs.“

ElroyJetson wrote:
The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.


Those numbers remind me of an interview with the head of the 7E7 program. The improvements were as a result of structures, aerodynamics, systems, and the combination of them.

We discussed the interview on here years ago when it came out.

ElroyJetson wrote:
My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient.


Again something that has been discussed and published before. Keep in mind the A330 while has similar floor area has more payload capability, around 5 tonnes.

From WSJ WSJ Jan. 7, 2014 "Boeing's Key Mission: Cut Dreamliner Cost"

"Dreamliners flown by United Continental Holdings Inc., UAL -1.47% the plane's sole U.S. operator, have been roughly 6% more cost-efficient per seat to operate in 2013 than the equivalent-sized Airbus A330s flown by several other U.S. airlines, according to an analysis by aviation consulting firm AirInsight of the carriers' filings with the Transportation Department. Such figures are often revised as airlines provide additional information."
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ElroyJetson
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 6:31 pm

zeke wrote:
ElroyJetson wrote:
Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763.


That was fuel burn per seat, a key parameter was a high density cabin to achieve that.

Longhauler posted this years ago on a similar thread regarding real performance on the AC 787 and 767.

“The B767-300 carried 211 passengers at FL370/390, from LHR-YYZ in 7:28 ... fuel burn was 37,800 Kgs.
The B787-8 carried 251 passengers at FL380/400 from YYZ-ZRH in 7:22 ... fuel burn was 34,200 Kgs.“

ElroyJetson wrote:
The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.


Those numbers remind me of an interview with the head of the 7E7 program. The improvements were as a result of structures, aerodynamics, systems, and the combination of them.

We discussed the interview on here years ago when it came out.

ElroyJetson wrote:
My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient.


Again something that has been discussed and published before. Keep in mind the A330 while has similar floor area has more payload capability, around 5 tonnes.

From WSJ WSJ Jan. 7, 2014 "Boeing's Key Mission: Cut Dreamliner Cost"

"Dreamliners flown by United Continental Holdings Inc., UAL -1.47% the plane's sole U.S. operator, have been roughly 6% more cost-efficient per seat to operate in 2013 than the equivalent-sized Airbus A330s flown by several other U.S. airlines, according to an analysis by aviation consulting firm AirInsight of the carriers' filings with the Transportation Department. Such figures are often revised as airlines provide additional information."



Your numbers seem much more reasonable. I got the 12-17% number from an old a.net thread which seemed too high. I ran my own numbers and the 788 looked about 7% better per seat than the A330-200. Not insignificant, but nowhere near the other number mentioned.

For those interested in 787 development and tech i highly recommend the book listed in the OP.


Thanks for the info you provided.
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BA777FO
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 6:57 pm

I know it's a slightly different comparison but on similar missions at similar payloads the 787-9 is consistently 20% more fuel efficient on a trip fuel basis than the 777-200ER.

I remember the 788 being similarly more efficient versus the 763. The A35K typically burns the same as the 772, but obviously is more 77W sized.
 
majano
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 7:02 pm

ElroyJetson wrote:
zeke wrote:
ElroyJetson wrote:
Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763.


That was fuel burn per seat, a key parameter was a high density cabin to achieve that.

Longhauler posted this years ago on a similar thread regarding real performance on the AC 787 and 767.

“The B767-300 carried 211 passengers at FL370/390, from LHR-YYZ in 7:28 ... fuel burn was 37,800 Kgs.
The B787-8 carried 251 passengers at FL380/400 from YYZ-ZRH in 7:22 ... fuel burn was 34,200 Kgs.“

ElroyJetson wrote:
The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.


Those numbers remind me of an interview with the head of the 7E7 program. The improvements were as a result of structures, aerodynamics, systems, and the combination of them.

We discussed the interview on here years ago when it came out.

ElroyJetson wrote:
My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient.


Again something that has been discussed and published before. Keep in mind the A330 while has similar floor area has more payload capability, around 5 tonnes.

From WSJ WSJ Jan. 7, 2014 "Boeing's Key Mission: Cut Dreamliner Cost"

"Dreamliners flown by United Continental Holdings Inc., UAL -1.47% the plane's sole U.S. operator, have been roughly 6% more cost-efficient per seat to operate in 2013 than the equivalent-sized Airbus A330s flown by several other U.S. airlines, according to an analysis by aviation consulting firm AirInsight of the carriers' filings with the Transportation Department. Such figures are often revised as airlines provide additional information."



Your numbers seem much more reasonable. I got the 12-17% number from an old a.net thread which seemed too high. I ran my own numbers and the 788 looked about 7% better per seat than the A330-200. Not insignificant, but nowhere near the other number mentioned.

For those interested in 787 development and tech i highly recommend the book listed in the OP.


Thanks for the info you provided.

Where is the book available at?
 
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zeke
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 7:23 pm

majano wrote:
Where is the book available at?


Amazon have it in hard cover and kindle for around $20
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ElroyJetson
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Re: 787 Fuel Efficency.

Mon Jan 27, 2020 10:32 pm

majano wrote:
ElroyJetson wrote:
zeke wrote:

That was fuel burn per seat, a key parameter was a high density cabin to achieve that.

Longhauler posted this years ago on a similar thread regarding real performance on the AC 787 and 767.

“The B767-300 carried 211 passengers at FL370/390, from LHR-YYZ in 7:28 ... fuel burn was 37,800 Kgs.
The B787-8 carried 251 passengers at FL380/400 from YYZ-ZRH in 7:22 ... fuel burn was 34,200 Kgs.“



Those numbers remind me of an interview with the head of the 7E7 program. The improvements were as a result of structures, aerodynamics, systems, and the combination of them.

We discussed the interview on here years ago when it came out.



Again something that has been discussed and published before. Keep in mind the A330 while has similar floor area has more payload capability, around 5 tonnes.

From WSJ WSJ Jan. 7, 2014 "Boeing's Key Mission: Cut Dreamliner Cost"

"Dreamliners flown by United Continental Holdings Inc., UAL -1.47% the plane's sole U.S. operator, have been roughly 6% more cost-efficient per seat to operate in 2013 than the equivalent-sized Airbus A330s flown by several other U.S. airlines, according to an analysis by aviation consulting firm AirInsight of the carriers' filings with the Transportation Department. Such figures are often revised as airlines provide additional information."



Your numbers seem much more reasonable. I got the 12-17% number from an old a.net thread which seemed too high. I ran my own numbers and the 788 looked about 7% better per seat than the A330-200. Not insignificant, but nowhere near the other number mentioned.

For those interested in 787 development and tech i highly recommend the book listed in the OP.


Thanks for the info you provided.

Where is the book available at?



Yeah. Zeke is correct. I got it through Amazon. If you are into aviation photography I would recommend the hardback.
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gloom
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 5:26 am

zeke wrote:
Longhauler posted this years ago on a similar thread regarding real performance on the AC 787 and 767.

“The B767-300 carried 211 passengers at FL370/390, from LHR-YYZ in 7:28 ... fuel burn was 37,800 Kgs.
The B787-8 carried 251 passengers at FL380/400 from YYZ-ZRH in 7:22 ... fuel burn was 34,200 Kgs.“


Zeke, could this example be a bit irrevelant due to 788 going sub-optimal FL (or higher payload)?

In the past 767-300ERs on routes to US (WAW-EWR/JFK/ORD-WAW) were typically using F320-340-360 profile, with 340 on NAT. Routes back typically 1000ft higher.
Nowadays, 788 are usually going 380-400, with 380 on NAT (some of them could be going higher, but NATs are F310-390 limited). 390 all the way on back route (due to pilots trying to avoid radiation).

I would expect much more difference in altitude than 1000ft. It seems math doesn't add up.

Unless of course there's extra payload influencing optimal FL. However, 1000ft higher than 767 is not usual for 788.

Cheers,
Adam
 
thepinkmachine
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 10:11 am

gloom wrote:
zeke wrote:
Longhauler posted this years ago on a similar thread regarding real performance on the AC 787 and 767.

“The B767-300 carried 211 passengers at FL370/390, from LHR-YYZ in 7:28 ... fuel burn was 37,800 Kgs.
The B787-8 carried 251 passengers at FL380/400 from YYZ-ZRH in 7:22 ... fuel burn was 34,200 Kgs.“


Zeke, could this example be a bit irrevelant due to 788 going sub-optimal FL (or higher payload)?

In the past 767-300ERs on routes to US (WAW-EWR/JFK/ORD-WAW) were typically using F320-340-360 profile, with 340 on NAT. Routes back typically 1000ft higher.
Nowadays, 788 are usually going 380-400, with 380 on NAT (some of them could be going higher, but NATs are F310-390 limited). 390 all the way on back route (due to pilots trying to avoid radiation).

I would expect much more difference in altitude than 1000ft. It seems math doesn't add up.

Unless of course there's extra payload influencing optimal FL. However, 1000ft higher than 767 is not usual for 788.

Cheers,
Adam


The levels quoted for the 787 seem perfectly legit. If anything, the 767 levels are higher then usual. Then again, LHR-YYZ IS a pretty short sector, so the 767 must have been pretty light.

Also, the 767 was likely flown into the wind (westbound), where you often fly above the OPT level to avoid the core of the jet stream. OTOH the 787 flight was eastbound, most likely with a tailwind, which often result in flying 1-2000 below OPT FL, to benefit from the extra speed of the jet core.
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zeke
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 10:21 am

thepinkmachine wrote:

The levels quoted for the 787 seem perfectly legit. If anything, the 767 levels are higher then usual. Then again, LHR-YYZ IS a pretty short sector, so the 767 must have been pretty light.

Also, the 767 was likely flown into the wind (westbound), where you often fly above the OPT level to avoid the core of the jet stream. OTOH the 787 flight was eastbound, most likely with a tailwind, which often result in flying 1-2000 below OPT FL, to benefit from the extra speed of the jet core.


Could it be that the 767 also had APB winglets ? They also provided higher cruise altitudes.
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strfyr51
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 11:44 am

WIederling wrote:
ElroyJetson wrote:
I recently read a great book on the development of the 787. The book is [i]The Birth of the 787 Dreamliner[i][by Edgar Turner.

Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763. As I recall, when ANA introduced the 788 on their NRT-CDG route they claimed a 21% fuel burn improvement versus their 763 ER.

The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.

My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient. That seems a little high to me as the A330 CEO is obviously newer tech than the 767.

Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family?


"The remaining 9% improvement is not specifically mentioned. "
Scaling gains, denser seatmap,
788 is slightly smaller than an A330-200
IMU the A330-200 took 6% more fuel for 12% more pax/payload ( fallout from the tanker wars.)


"Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family? "

More like 8% ( At least that is what Leeham got from asking fleet managers back then.)

One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.
 
tommy1808
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 11:49 am

strfyr51 wrote:
WIederling wrote:
ElroyJetson wrote:
I recently read a great book on the development of the 787. The book is [i]The Birth of the 787 Dreamliner[i][by Edgar Turner.

Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763. As I recall, when ANA introduced the 788 on their NRT-CDG route they claimed a 21% fuel burn improvement versus their 763 ER.

The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.

My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient. That seems a little high to me as the A330 CEO is obviously newer tech than the 767.

Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family?


"The remaining 9% improvement is not specifically mentioned. "
Scaling gains, denser seatmap,
788 is slightly smaller than an A330-200
IMU the A330-200 took 6% more fuel for 12% more pax/payload ( fallout from the tanker wars.)


"Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family? "

More like 8% ( At least that is what Leeham got from asking fleet managers back then.)

One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.


Is that why no one else is going bleedless even 15 years later, despite fighting for every tenth of a percent in fuel burn reduction?
So far it seems to have been rather a "worth trying, but didn't pay off" sort of invention.

Best regards
Thomas
Well, there is prophecy in the bible after all: 2 Timothy 3:1-6
 
WIederling
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 12:24 pm

tommy1808 wrote:
strfyr51 wrote:
One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.


Is that why no one else is going bleedless even 15 years later, despite fighting for every tenth of a percent in fuel burn reduction?
So far it seems to have been rather a "worth trying, but didn't pay off" sort of invention.

Stuff:

Not using potentially contaminated bleed air for "PAX aeration" it a good thing (TM).

787 engines aren't really "no bleed". They provide bleed air for engine purposes like deice.
another case is using bleed to manage engine tuning.

bleed air take off and generator take off both provide power with an associated sfc.
( haven't seen useful numbers, though )
Bleed air depresses engine efficiency increasing fuel flow.
Generator takeoff increases engine power level and thus fuel flow.
( But then bleed is also used to manage engine tuning. s.o.)

Using hot ( from adiabatic compression ) bleed air directly for deicing is thermodynamically more efficient
than electric heating with electricity generated via a Carnot process with limited efficiency.

"Packs" are probably the most ambiguous use case efficiency wise.

Airbus staying with bleed seems to have changed their systems towards electric actuation.
No longer a ratsnest of pneumatic control and actuation to control bleed use.

Performance of Trent 1000 TEN vs Trent 7000 will be interesting to look at.
Murphy is an optimist
 
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Starlionblue
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 12:42 pm

strfyr51 wrote:
WIederling wrote:
ElroyJetson wrote:
I recently read a great book on the development of the 787. The book is [i]The Birth of the 787 Dreamliner[i][by Edgar Turner.

Lots of technical details and photos highlighting the development and construction of the 787. In the book it mentioned Boeing's goal of a 20% improvement in fuel burn over the prior generation 763. As I recall, when ANA introduced the 788 on their NRT-CDG route they claimed a 21% fuel burn improvement versus their 763 ER.

The book states 8% of the fuel burn improvement was due to better engine performance and 3% improvement was due to use of composites. The remaining 9% improvement is not specifically mentioned.

My question is this: When I look at fuel burn numbers between a 788 and a A330-200 which are virtually identical in size (floor space is within 2-3%), I have seen claims that the 788 is somewhere between 12%-17% more fuel efficient. That seems a little high to me as the A330 CEO is obviously newer tech than the 767.

Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family?


"The remaining 9% improvement is not specifically mentioned. "
Scaling gains, denser seatmap,
788 is slightly smaller than an A330-200
IMU the A330-200 took 6% more fuel for 12% more pax/payload ( fallout from the tanker wars.)


"Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family? "

More like 8% ( At least that is what Leeham got from asking fleet managers back then.)

One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.


Electrically generated or bleed powered, the energy still has to be extracted from the engines. The consumers are still all there.

The question is whether less energy is lost with electric generation instead of direct bleed, and if so how much.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
majano
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Re: 787 Fuel Efficency.

Tue Jan 28, 2020 8:12 pm

ElroyJetson wrote:
majano wrote:
ElroyJetson wrote:


Your numbers seem much more reasonable. I got the 12-17% number from an old a.net thread which seemed too high. I ran my own numbers and the 788 looked about 7% better per seat than the A330-200. Not insignificant, but nowhere near the other number mentioned.

For those interested in 787 development and tech i highly recommend the book listed in the OP.


Thanks for the info you provided.

Where is the book available at?



Yeah. Zeke is correct. I got it through Amazon. If you are into aviation photography I would recommend the hardback.

Thank you very much to both of you.
 
JayinKitsap
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Re: 787 Fuel Efficency.

Wed Jan 29, 2020 7:22 am

Starlionblue wrote:
strfyr51 wrote:
WIederling wrote:

"The remaining 9% improvement is not specifically mentioned. "
Scaling gains, denser seatmap,
788 is slightly smaller than an A330-200
IMU the A330-200 took 6% more fuel for 12% more pax/payload ( fallout from the tanker wars.)


"Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family? "

More like 8% ( At least that is what Leeham got from asking fleet managers back then.)

One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.


Electrically generated or bleed powered, the energy still has to be extracted from the engines. The consumers are still all there.

The question is whether less energy is lost with electric generation instead of direct bleed, and if so how much.


Pneumatic and steam systems share of their markets are ramping down across industry after industry, electrical is growing. The newer electrical motors are getting rid of gear boxes too, like in clothes washers. The system total cost appears to be less, although which uses less energy it seems a bit debatable. Going from fuel to shaft power is matched, but compressor bleed air for packs vs electrical compressors & heating or heat pump depends on efficiency across a load range. I could probably do calcs to show that each is more efficient with just changes to the assumptions.
 
strfyr51
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Re: 787 Fuel Efficency.

Thu Jan 30, 2020 1:24 am

tommy1808 wrote:
strfyr51 wrote:
WIederling wrote:

"The remaining 9% improvement is not specifically mentioned. "
Scaling gains, denser seatmap,
788 is slightly smaller than an A330-200
IMU the A330-200 took 6% more fuel for 12% more pax/payload ( fallout from the tanker wars.)


"Does anyone have any thoughts about this. How efficient is the 787 versus the A 330 CEO family? "

More like 8% ( At least that is what Leeham got from asking fleet managers back then.)

One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.


Is that why no one else is going bleedless even 15 years later, despite fighting for every tenth of a percent in fuel burn reduction?
So far it seems to have been rather a "worth trying, but didn't pay off" sort of invention.

Best regards
Thomas

So? Whom else has tried to go Bleed less? If I'm not mistaken? Nobody! the 787 carries Huge generating power driven by the engine accessory Gearbox. so everything is electrically driven. Who Else holds Patents that would allow them to use a system like Boeing's? Look at the hoops Airbus had to go through to not infringe on Boeing patents. Hell! they had t rename material Specs as to Not use Mil-Spec and AN specs in Materials and Hardware we still used both MS and NAS hardware and on Occasion even Boeing repair Specifications which we got by Airbus by NOT mentioning Boeing Including Composite repairs etc. Airbus knew the origin though they approved them anyway as long as we never mentioned the Boeing SRM. They didn't just buy any repair But they bought off on quite a few.. And they helps us put the aircraft back in service that much quicker rather than wait for them to research the repair.
 
strfyr51
Posts: 4985
Joined: Tue Apr 10, 2012 5:04 pm

Re: 787 Fuel Efficency.

Thu Jan 30, 2020 1:26 am

strfyr51 wrote:
tommy1808 wrote:
strfyr51 wrote:
One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.


Is that why no one else is going bleedless even 15 years later, despite fighting for every tenth of a percent in fuel burn reduction?
So far it seems to have been rather a "worth trying, but didn't pay off" sort of invention.

Best regards
Thomas

So? Whom else has tried to go Bleed less? If I'm not mistaken? Nobody! the 787 carries Huge generating power driven by the engine accessory Gearbox. so everything is electrically driven. Who Else holds Patents that would allow them to use a system like Boeing's? Look at the hoops Airbus had to go through to not infringe on Boeing patents. Hell! they had t rename material Specs as to Not use Mil-Spec and AN specs in Materials and Hardware we still used both MS and NAS hardware and on Occasion even Boeing repair Specifications which we got by Airbus by NOT mentioning Boeing Including Composite repairs etc. Airbus knew the origin though they approved them anyway as long as we never mentioned the Boeing SRM. They didn't just buy any repair But they bought off on quite a few.. And they helps us put the aircraft back in service that much quicker rather than wait for them to research the repair.

We always got the NTO to our proposals (No Technical Objection)
 
Chemist
Posts: 750
Joined: Tue Oct 20, 2015 4:46 am

Re: 787 Fuel Efficency.

Thu Jan 30, 2020 5:53 am

Perhaps nobody else is bleedless because there have been no new clean sheet AC since 787 was introduced?
 
tommy1808
Posts: 13254
Joined: Thu Nov 21, 2013 3:24 pm

Re: 787 Fuel Efficency.

Thu Jan 30, 2020 6:27 am

strfyr51 wrote:
tommy1808 wrote:
strfyr51 wrote:
One thing that would make the 787 more fuel efficient is that the engines do not supply Bleed Pressure for pressurization or Pneumatic needs of the fuselage as all of that is Electrically generated . So the Aircraft can climb to altitude using less fuel or with a higher power setting, No Bleeds also means the engines could be on the w00ing quite a bit longer as well.


Is that why no one else is going bleedless even 15 years later, despite fighting for every tenth of a percent in fuel burn reduction?
So far it seems to have been rather a "worth trying, but didn't pay off" sort of invention.

Best regards
Thomas

So? Whom else has tried to go Bleed less? If I'm not mistaken? Nobody! the 787 carries Huge generating power driven by the engine accessory Gearbox. so everything is electrically driven. Who Else holds Patents that would allow them to use a system like Boeing's?


Gas turbine with a generator attached to power electrical actuators? That is so prior art my grandfather would have called it that.

That no one else has tried to go bleedless is my point. That the A330neo seemingly has essentially identical fuel born proves it further. Is the 787 too heavy compared to the A330neo? Hell no? Has its wing design been incompetent? Unlikely. Are the engines worse? Pretty definitely not. Other than "bleedless does have no or really marginal effect" there isn´t a good explanation.

Now can it have other advantages when it comes to building and maintaining those system, which i think is a fair assumption, but either it isn´t the efficiency booster Boeing marketed it to be or the rest of the aircraft was executed incompetent. Which one is it?

Chemist wrote:
Perhaps nobody else is bleedless because there have been no new clean sheet AC since 787 was introduced?


There has been the Irkut MC-21 and a couple of other, plenty of business jets and new engines for business jet that could have used it too (and those customers would gladly shell out the money for cleaner cabin air) .... the 777x is certainly enough of a makeover to do it if it is worth it.

best regards
Thomas
Well, there is prophecy in the bible after all: 2 Timothy 3:1-6
 
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Starlionblue
Posts: 20032
Joined: Fri Feb 27, 2004 9:54 pm

Re: 787 Fuel Efficency.

Thu Jan 30, 2020 11:14 am

Chemist wrote:
Perhaps nobody else is bleedless because there have been no new clean sheet AC since 787 was introduced?


No new clean-sheet aircraft since the 787? The A350 and A220 would like a word...
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Chemist
Posts: 750
Joined: Tue Oct 20, 2015 4:46 am

Re: 787 Fuel Efficency.

Fri Jan 31, 2020 2:04 am

Airbus is conservative and they probably weren't ready to pivot on the bleedless. Proabably also true for BBD on the A220. I suspect that they're all waiting to see if it was worth it or not. Boeing was being bold and we're waiting to see if it pans out.
Is there a verdict on that yet? Would Boeing or Airbus do bleedless on an all new jet next time?
 
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Starlionblue
Posts: 20032
Joined: Fri Feb 27, 2004 9:54 pm

Re: 787 Fuel Efficency.

Fri Jan 31, 2020 3:10 am

Are Airbus really conservative compared to Boeing? It always seems to me that Airbus is pushing more on the technical side than Boeing, and that the 787 is the exception that confirms the rule. This has leed to the joke about the 787 being the "best Airbus that Boeing ever built".

Chemist wrote:
Airbus is conservative and they probably weren't ready to pivot on the bleedless. Proabably also true for BBD on the A220. I suspect that they're all waiting to see if it was worth it or not. Boeing was being bold and we're waiting to see if it pans out.
Is there a verdict on that yet? Would Boeing or Airbus do bleedless on an all new jet next time?


I suppose it would depend not only on the 787, but also on the development of electrics since then. I have it on reasonably reliable authority that electrics are becoming a big thing in another transportation industry, but I can't put my finger on which one... ;)
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Chemist
Posts: 750
Joined: Tue Oct 20, 2015 4:46 am

Re: 787 Fuel Efficency.

Fri Jan 31, 2020 6:31 am

Starlionblue wrote:
Are Airbus really conservative compared to Boeing? It always seems to me that Airbus is pushing more on the technical side than Boeing, and that the 787 is the exception that confirms the rule. This has leed to the joke about the 787 being the "best Airbus that Boeing ever built".

Chemist wrote:
Airbus is conservative and they probably weren't ready to pivot on the bleedless. Proabably also true for BBD on the A220. I suspect that they're all waiting to see if it was worth it or not. Boeing was being bold and we're waiting to see if it pans out.
Is there a verdict on that yet? Would Boeing or Airbus do bleedless on an all new jet next time?


I suppose it would depend not only on the 787, but also on the development of electrics since then. I have it on reasonably reliable authority that electrics are becoming a big thing in another transportation industry, but I can't put my finger on which one... ;)


Airbus was certainly more innovative on a flight control system starting way back with the A320, but the 787 construction architecture is more innovative probably than the A350 with full composite barrels, bleedless air/all electric - versus composite panels on a composite frame and traditional bleed on the A350.
 
WIederling
Posts: 9309
Joined: Sun Sep 13, 2015 2:15 pm

Re: 787 Fuel Efficency.

Fri Jan 31, 2020 7:44 am

Starlionblue wrote:
I suppose it would depend not only on the 787, but also on the development of electrics since then. I have it on reasonably reliable authority that electrics are becoming a big thing in another transportation industry, but I can't put my finger on which one... ;)


electrics are on the up . overall.
BUT
Boeing was one+ generation too early int their adoption.
there are other domains that strongly push power electronics forward.
This should have been leveraged.

efficiency gains would have obviated things like water cooling as used on the 787.
increased reliability too.
Murphy is an optimist
 
tommy1808
Posts: 13254
Joined: Thu Nov 21, 2013 3:24 pm

Re: 787 Fuel Efficency.

Fri Jan 31, 2020 8:57 am

Chemist wrote:
Starlionblue wrote:
Are Airbus really conservative compared to Boeing? It always seems to me that Airbus is pushing more on the technical side than Boeing, and that the 787 is the exception that confirms the rule. This has leed to the joke about the 787 being the "best Airbus that Boeing ever built".

Chemist wrote:
Airbus is conservative and they probably weren't ready to pivot on the bleedless. Proabably also true for BBD on the A220. I suspect that they're all waiting to see if it was worth it or not. Boeing was being bold and we're waiting to see if it pans out.
Is there a verdict on that yet? Would Boeing or Airbus do bleedless on an all new jet next time?


I suppose it would depend not only on the 787, but also on the development of electrics since then. I have it on reasonably reliable authority that electrics are becoming a big thing in another transportation industry, but I can't put my finger on which one... ;)


Airbus was certainly more innovative on a flight control system starting way back with the A320, but the 787 construction architecture is more innovative probably than the A350 with full composite barrels, bleedless air/all electric - versus composite panels on a composite frame and traditional bleed on the A350.


Airbus would claim the Panel on frame design is an innovation over the full composite barrel....

Best regards
Thomas
Well, there is prophecy in the bible after all: 2 Timothy 3:1-6

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