rheinwaldner
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Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 12:18 pm

I have found an interesting analysis by leehamnet, that deals with expected figures of the two new re-engined NB's:
http://airinsight.com/2011/10/05/airbus-takes-on-max/

The report is based on the first profound defence from Airbus against Boeing's creative number measuring methodology. The report was presented at the ISTAT conference.

Depending on who tells you something e.g. the numbers for fuel per seat vary between +7% and -8%. See here:
http://airinsight.com/wp-content/uploads/2011/10/blockfuel-neo-v-max1.jpg

Some quotes to whet your appeitie:

Quote:
The controversy might be summed it with this question: If CFM had to upsize the fan on the LEAP to be competitive with the GTF on the neo, how can it now downsize the fan for the MAX and achieve the same result?
Quote:
Airbus, which has up to now claimed the NEO is “up to” 15% better than today’s A320 family, revealed for the first time that this is “conservative,” ... the A319neo will be slightly more than 15% better than today’s A319 at 500nm and about 17% better at 2,500nm. Airbus concludes that the A319neo will be 7% better than the 737-7 (MAX) on a per-seat and a per trip basis.

According to Airbus, Boeing used the following tricks to reach their conclusions:
- Deny any improvement from PIP's for the A320
- Pick the oldest and weakest A320 engine for the comparison
- Pick the most favorable range for the 737 and the worst for the A320
 
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Stitch
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 12:23 pm

The only number that is going to matter is what each plane does in an airline's specific configuration on their specific routes using their specific mission rules.

The rest - especially from the OEMs - is just noise.
 
peanuts
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 12:28 pm

There are way too many variables in this maze of sales and marketing to come to a reasonable "draw". One of the most important factors, often overlooked by many, is: what will my plane cost over the lifetime that I own it?
ACQUISITION COST can make that total number make or break a deal.
Both Airbus and Boeing try to build a plane for the least amount of money and highest potential amount of profit. There are many ways to get there...
 
BoeingVista
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 12:34 pm

Until Boeing fix an engine size, thrust level and OEW for the MAX all these comparisons are a meaningless.

[Edited 2011-10-12 06:17:45]
BV
 
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scbriml
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 12:46 pm

Given the sales we've already seen for the A320neo and the commitments that Boeing say they have for the 737MAX, it's clear that both will sell in large numbers regardless of which one may or may not be better on any specific mission.

The only potential I can see for Airbus to clearly "trump" the 737MAX would be if the GTF is significantly better than the LEAP-X. Frankly, I'd be shocked if we saw anything other than a 50-50 (plus or minus 5%) market split.
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rheinwaldner
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 1:01 pm

Quoting Stitch (Reply 1):
The only number that is going to matter is what each plane does in an airline's specific configuration on their specific routes using their specific mission rules.

Do you think the range Boeing picked for their communications (500nm) is a good average to get a good impression how good the aircraft will be in reality? Have you noticed that in this Airbus report there are specific improvements mentioned for different ranges?
 
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lightsaber
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 1:11 pm

Quoting rheinwaldner (Thread starter):
Quote:
The controversy might be summed it with this question: If CFM had to upsize the fan on the LEAP to be competitive with the GTF on the neo, how can it now downsize the fan for the MAX and achieve the same result?

Boeing is also neglecting the 'Sharklets' that will help the A320.

Interesting numbers. IMHO the 738 is at a little more advantage to the A320 than the charts suggest, partially as it has room for another row of passengers.

Due to weight, the 738 will still do well on shorter missions. The question will be, at what mission length will the A32X family have a clear advantage? The Airbus view of the 738MAX is definately for the EIS configuration. Once the CMC turbine is installed, the 738MAX will gain a few more percent.

Something isn't adding up. For example, the A320NEO will benefit far more than 15% on TCON missions. Currently, those missions are too close to the plane's range, when going against the wind, for great economics. The 738 (current) has a nice advantage on TCON missions (US).

Quoting peanuts (Reply 2):
One of the most important factors, often overlooked by many, is: what will my plane cost over the lifetime that I own it?

   Which also includes resale. Due to the high commonality, 738s should be easier to place by leasing agencies.

Pratt is supposed to be keeping 4% fuel burn in reserve. If that is the case, than the A320 and A321 will *almost* have TATL range. To say the least, that will have a large number of 752 operators knocking on their door for those last few hundred nm of range. The same can be said about the 738.

Any way we look at it, the new engines will make the 739ERMAX and A321 much more economical airframes. IMHO, both the 738MAX and 739MAX will sell well for Boeing. For Airbus, I expect a large shift, in the long run, to the A321NEO. I consider the 73GMAX and A319MAX loss leaders that will have sales analogous to the 735/736.

Lightsaber
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astuteman
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 2:07 pm

Quoting lightsaber (Reply 6):
Something isn't adding up. For example, the A320NEO will benefit far more than 15% on TCON missions Currently, those missions are too close to the plane's range, when going against the wind, for great economics. The 738 (current) has a nice advantage on TCON missions (US).

Bear in mind that the A320 without winglets carries 18.6 tonnes of fuel vs 20.9 tonnes for the 737NG. I have heard it said on here that in severe headwinds, current gen A320's can sometimes be MTOW limited, and that may be at least in part due to a need to minimise drag in order to make the still-air distance on 18.6 tonnes of fuel.
On the NG, you just load her up to 20.9 tonnes of fuel, 12% more than the A320 can carry, and job's a good un.

A CFM powered A320 may have a 4% fuel burn advantage AT LONG RANGE over a 737-800 (according to the FCOM's), but with 12% less fuel, is going to fly 8% less distance if fuel limited.
With winglets, the A320 should have a 7%-8% fuel burn advantage AT LONG RANGE, but will still fall 4%-5% short on range when fuel limited.

I'm still wondering if Airbus, in their wing mods to accommodate the sharklets, may have found some extra wing tank volume.
If they have it may change the picture completely.

Rgds
 
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 2:36 pm

Again, the chart is from Airbus's point of view with their rosy point of view and the absolute worst of Boeing, that chart is meaningless to be just like Boeing's numbers are at the moment.

Everyone knows that on normal under 1000 miles runs, currently, the 738 has a slight advantage over the 320. Over that, the 320 has a slight advantage. In other words, the 2 aircraft are comparable. That is just common knowledge. The chart puts the B738 at a 7% disadvantage as it stands today, that is simply not true, especially if we count the extra capacity (passengers, payload, range) of the 738.

There is no way, in my opinion, could the MAX be only 3% better than the current A320, and that the NEO will be 12% better than the B737-8MAX. There is no way Boeing would have even considered the MAX if they will have a 12% disadvantage out the door to the NEO.

These numbers are bogus, from both ends. I think the truth is really down the middle. They will end up being comparable and maintain the status quo. The MAX will continue to have a slight advantage at under 1000nm, and the NEO have a slight advantage over that over that. But that slight advantage will no way be 12%.
 
rheinwaldner
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 2:51 pm

Quoting fpetrutiu (Reply 8):
Again, the chart is from Airbus's point of view with their rosy point of view and the absolute worst of Boeing, that chart is meaningless to be just like Boeing's numbers are at the moment.

Which point of view? This data for the first time goes a little deeper, so we can actually go into the details and point out the tricks Boeing used to "shine". And we can judge them as unfair. So I ask what are the tricks Airbus uses?

Does Airbus quote the 738-numbers without any pip's or just the oldest engines? Is the capability of the 738 judged unfair in any ways by Airbus (e.g. uncorrect seat capacity)? It is time to clarify things on this level now....

Quoting fpetrutiu (Reply 8):
The chart puts the B738 at a 7% disadvantage as it stands today, that is simply not true, especially if we count the extra capacity (passengers, payload, range) of the 738.

The chart is specific enough to mention "block fuel". From that and the other fixpoints we can derive the fuel-per-seat metrics. The chart contains all these information in a transparent ways. To question the conclusion you have to question hard things like the corrected seatcount.
 
bonusonus
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 3:16 pm

Quoting lightsaber (Reply 6):
Something isn't adding up. For example, the A320NEO will benefit far more than 15% on TCON missions. Currently, those missions are too close to the plane's range, when going against the wind, for great economics. The 738 (current) has a nice advantage on TCON missions (US).

The A320 can do transcon, but has issues with winter headwinds once in a while. I thought the 738 didn't have the legs for true transcon (like JFK-LAX).
Anyone want to throw down some range statistics for the current A320 family vs the current 737NG family?
 
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 3:57 pm

Quoting scbriml (Reply 4):
Given the sales we've already seen for the A320neo and the commitments that Boeing say they have for the 737MAX, it's clear that both will sell in large numbers regardless of which one may or may not be better on any specific mission.

So true.   

Quoting scbriml (Reply 4):
The only potential I can see for Airbus to clearly "trump" the 737MAX would be if the GTF is significantly better than the LEAP-X.

That would be my expectation too.  .

Quoting lightsaber (Reply 6):
Boeing is also neglecting the 'Sharklets' that will help the A320.

Well, that might be the basis or their original bogus claim that the current B737-NG would still be better then a NEO-A320 version.  
Quoting astuteman (Reply 7):
I'm still wondering if Airbus, in their wing mods to accommodate the sharklets, may have found some extra wing tank volume.
If they have it may change the picture completely.

They still have not released any details about fuel capacity on the NEO-versions. That is a number also I am very curious about.

Quoting rheinwaldner (Reply 9):
Does Airbus quote the 738-numbers without any pip's or just the oldest engines? Is the capability of the 738 judged unfair in any ways by Airbus (e.g. incorrect seat capacity)? It is time to clarify things on this level now....

These numbers are for sure a lot more honest then the earlier "studies" we have seen being posted here. But in the end the proof of the pudding is in the eating. So we will have to wait till 2017 or so to make real world comparisons between the two dominating narrow body airliners around.

Both planes will be highly successful, though I do expect the NEO to have the upper hand in sales and performance. The big question is how much will that influence the all deciding factor, the TCO?  .

[Edited 2011-10-12 09:02:43]
 
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ADent
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 4:09 pm

Quoting bonusonus (Reply 10):
The A320 can do transcon, but has issues with winter headwinds once in a while. I thought the 738 didn't have the legs for true transcon (like JFK-LAX).

Haven't seen too many complaints here about the 737-800 transcon.

I have seen complaints on SEA-HNL for the -800 and transcon on the 737-900ER (and the latter is usually about weight limits or blocked seats more than fuel stops).
 
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 4:15 pm

Quoting astuteman (Reply 7):
Bear in mind that the A320 without winglets carries 18.6 tonnes of fuel vs 20.9 tonnes for the 737NG.

Good point. It is interesting how there is a 'double crossover' in when each of the current 737NG vs. A320 match each other's economics. It makes discussions on the two type very interesting. Only a double crossing due to the 738s lighter weight and greater fuel carrying capacity. The interesting trade offs of A/C design.

Quoting astuteman (Reply 7):
With winglets, the A320 should have a 7%-8% fuel burn advantage AT LONG RANGE, but will still fall 4%-5% short on range when fuel limited.

  

and if Pratt has held 4% fuel burn in reserve.   

Quoting astuteman (Reply 7):
I'm still wondering if Airbus, in their wing mods to accommodate the sharklets, may have found some extra wing tank volume.

I know Airbus is working on more fuel for the A321. I do not know anything more than MTOW studies are being done. And Pratt promised to deliver an engine with room for an "easy" 2K of thrust increase.   Then again, Pratt still hasn't delivered the PW4175 as promised.  

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roseflyer
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 4:42 pm

Quoting rheinwaldner (Reply 9):
Quoting fpetrutiu (Reply 8):
Again, the chart is from Airbus's point of view with their rosy point of view and the absolute worst of Boeing, that chart is meaningless to be just like Boeing's numbers are at the moment.

Which point of view? This data for the first time goes a little deeper, so we can actually go into the details and point out the tricks Boeing used to "shine". And we can judge them as unfair. So I ask what are the tricks Airbus uses?

Does Airbus quote the 738-numbers without any pip's or just the oldest engines? Is the capability of the 738 judged unfair in any ways by Airbus (e.g. uncorrect seat capacity)? It is time to clarify things on this level now....

I think the point is that the chart that you showed on this page is Airbus' view and then Airbus' interpretation of Boeing's view. It's not an analysis by a third party. It is an article based on a briefing given by Airbus and the charts are Airbus derived. The article states how confusing the situation is:

AirInsight received a briefing from Airbus at the ISTAT European conference in Barcelona, Spain, September 20. During this briefing, Airbus provided its analysis by sub-type, in detail—something Boeing has so far declined to do for its 737NG and 737MAX.

Boeing, in media briefings prior to the Paris Air Show, confined its direct comparison to the 737-800 and the A320. Following the roll-out of its MAX, Boeing provided some general data to illustrate its assertions that the 737 family is more economical than the Airbuses.

And later in the article

It took a long time to get here, but now let’s talk about the Airbus briefing we received at ISTAT. The following three charts illustrate the current airplanes vs the competitor and the re-engined aircraft vs the competitor. A key element to keep in mind is that Boeing talks about total costs: ownership and direct operating costs. Below, Airbus is only talking about block fuel comparison. Thus, we’re talking about apples and oranges, regardless of the benchmark that is being used. Boeing doesn’t talk about block fuel comparison and Airbus doesn’t talk about total costs.


In general my personal opinion is that it is too hard to do a total analysis of the comparison in costs. It's hard enough to compare the 737NG and A320 on a total cost of ownership basis now. Usually plots show that the A320 has lower trip costs and lower fuel burn, but the 737-800 has lower costs per seat. 73G vs A319 and 739ER vs A321 plots are similarly confusing. However what I find most interesting is the attempt at an objective comparison at the end of the article, which shows:

737-7 vs A319neo

Fuel burn per seat: NEO is better by 3%

COC per seat mile: NEO is better by 4%

COC per trip: NEO is better by 1%

737-8 vs A320neo

Fuel burn per passenger: MAX is better by 4% (with 12 more passengers)

COC per seat mile: MAX is better by 4%

COC per trip: NEO is better by 3%

737-9 vs A321neo

Fuel burn per passenger: NEO better by 2%

COC per seat mile: NEO better by 1%

COC per trip: MAX better by 4% (at 5% less capacity)

That information shows some A320NEO advantages and some 737MAX advantages depending on situation.

Quoting astuteman (Reply 7):
Bear in mind that the A320 without winglets carries 18.6 tonnes of fuel vs 20.9 tonnes for the 737NG. I have heard it said on here that in severe headwinds, current gen A320's can sometimes be MTOW limited, and that may be at least in part due to a need to minimise drag in order to make the still-air distance on 18.6 tonnes of fuel.
On the NG, you just load her up to 20.9 tonnes of fuel, 12% more than the A320 can carry, and job's a good un.

A CFM powered A320 may have a 4% fuel burn advantage AT LONG RANGE over a 737-800 (according to the FCOM's), but with 12% less fuel, is going to fly 8% less distance if fuel limited.
With winglets, the A320 should have a 7%-8% fuel burn advantage AT LONG RANGE, but will still fall 4%-5% short on range when fuel limited.

How often do 737s and A320s actually fill their tanks to their max capacity? I was under the impression that range is rarely limited on fuel capacity.
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flipdewaf
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 4:59 pm

Quoting RoseFlyer (Reply 14):
Fuel burn per passenger: MAX is better by 4% (with 12 more passengers)

Thats interesting, I was under the impression that the A320 could hold 180 pax going up to 183 with the new galley and the 738 could go up to 186.

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astuteman
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 5:28 pm

Quoting RoseFlyer (Reply 14):
How often do 737s and A320s actually fill their tanks to their max capacity? I was under the impression that range is rarely limited on fuel capacity

Not very often, I suspect. But there IS a tendency on here to focus on the very occasional shortcomings of an A320 on the more challenging transcons as if it were representative of the difference between both aircraft in all cases.
And in this particular case, then space in the fuel tanks might well be a differentiator.

As Lightsaber also suggests, it might be relevant if there is a REAL push to get the NEO's up to some sort of TATL capability

Quoting flipdewaf (Reply 15):
Thats interesting, I was under the impression that the A320 could hold 180 pax going up to 183 with the new galley and the 738 could go up to 186.

Ryanair's 738's have 189 seats.

And Easyjet's A320's ALREADY have 183 seats, albeit on a 1" shorter pitch than FY's 738's

http://www.seatguru.com/airlines/eas...s/easyJet_Airlines_Airbus_A320.php

Rgds
 
roseflyer
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 6:03 pm

Quoting astuteman (Reply 16):

Quoting flipdewaf (Reply 15):
Thats interesting, I was under the impression that the A320 could hold 180 pax going up to 183 with the new galley and the 738 could go up to 186.

Ryanair's 738's have 189 seats.

And Easyjet's A320's ALREADY have 183 seats, albeit on a 1" shorter pitch than FY's 738's

Depending on airline, the difference is between 6 and 16 based on airlines operating both types and comparisons of max density configuration airlines.
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Stitch
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 6:53 pm

Quoting rheinwaldner (Reply 5):
Do you think the range Boeing picked for their communications (500nm) is a good average to get a good impression how good the aircraft will be in reality?

It might very well be, if the majority of 737 missions are 500nm or less.



Quoting rheinwaldner (Reply 5):
Have you noticed that in this Airbus report there are specific improvements mentioned for different ranges?

Yes. But if those improvements are at their maximum benefit at longer stage lengths, then it is not a surprise Airbus is using longer stage lengths.
 
ikramerica
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 7:02 pm

Quoting rheinwaldner (Thread starter):
According to Airbus, Boeing used the following tricks to reach their conclusions:
- Deny any improvement from PIP's for the A320
- Pick the oldest and weakest A320 engine for the comparison
- Pick the most favorable range for the 737 and the worst for the A320

Sounds good. Isn't that what PR is all about? Is Airbus going to show in their numbers the most favorable comparison for Boeing? I wouldn't expect them to.

Quoting RoseFlyer (Reply 14):
I think the point is that the chart that you showed on this page is Airbus' view and then Airbus' interpretation of Boeing's view.

It's an important point. It's as much propaganda as the Boeing numbers are.

These birds are so far off, it's silly. Until the engines test, it's meaningless.
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roseflyer
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 7:14 pm

Quoting Stitch (Reply 18):

It might very well be, if the majority of 737 missions are 500nm or less.

Average trip is closer to 900 miles. Average stage length is about 2 hours for the 737NG and A320.

Quoting ikramerica (Reply 19):
Quoting rheinwaldner (Thread starter):
According to Airbus, Boeing used the following tricks to reach their conclusions:
- Deny any improvement from PIP's for the A320
- Pick the oldest and weakest A320 engine for the comparison
- Pick the most favorable range for the 737 and the worst for the A320

Sounds good. Isn't that what PR is all about? Is Airbus going to show in their numbers the most favorable comparison for Boeing? I wouldn't expect them to.

I think that's why Airbus numbers are showing fuel burn while Boeing numbers show trip by seat and total operating costs. They both show what makes their models look best and avoid even comparisons. It makes it easy to always show that they are best. I think the article showing the per seat and total costs per model was very interesting because it shows how there is a lot of parity and no one is better than the other in all cases or even a significant majority of the cases.
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astuteman
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 7:30 pm

Quoting RoseFlyer (Reply 20):
I think the article showing the per seat and total costs per model was very interesting because it shows how there is a lot of parity and no one is better than the other in all cases or even a significant majority of the cases.

Which is of course equally reflected in the respective market shares  

Rgds
 
futureatp
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 7:32 pm

Can anyone tell me the fuel burn in lbs per hr at a given cruise altitude, at max take off weight (minus fuel it took to get there) of any of these airplanes? Then what the fuel burn numbers would be after 3hrs in flight? Since I have seen that no airframe is created equal (Ive seen aircraft swaps that resulted in a 200lb planned increase in fuel?!!) im thinking a range or approximate numbers would suffice. Oh, and standard day conditions  
 
planewasted
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 7:36 pm

The A330 can can compete, and even beat the 777 on lots of routes. And the A330 has much smaller engines than the 777! Why would this not apply to the A320NEO vs 737MAX?

[Edited 2011-10-12 12:38:00]
 
SASMD82
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 7:43 pm

Quoting BoeingVista (Reply 3):
Until Boeing fix an engine size, thrust level and OEW for the MAX all these comparisons are a meaningless.

I totally agree with you! I think still has no idea how the MAX actually will look like (of course they've got artist impressions but there is no real idea of what the MAX will be, I am sure it will incorporate fly-by-wire   ).

Quoting planewasted (Reply 23):
The A330 can can compete, and even beat the 777 on lots of routes. And the A330 has a lot smaller engines compared to the 777! Why would this not apply to the A320NEO vs 737MAX?

And again, I agree! The A330-300 is actually superior to the B777-200(ER) for basically all the missions up to 8 or 9 hours.
 
roseflyer
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 7:54 pm

Quoting astuteman (Reply 21):
Quoting RoseFlyer (Reply 20):
I think the article showing the per seat and total costs per model was very interesting because it shows how there is a lot of parity and no one is better than the other in all cases or even a significant majority of the cases.

Which is of course equally reflected in the respective market shares

It shows close to parity between the A320 and 737NG. Airbus impressed and got many orders for the NEO with its projections. We'll see what happens with the MAX and when the airplanes deliver. It's hard to know what the two planes will look like and I don't think the chart at the top of this thread is a very reasonable expectation of the outcome. Many times airplanes have received orders and looked promising early on, but it isn't necessarily a reflection of orders/market share over the airplane's production run.
If you have never designed an airplane part before, let the real designers do the work!
 
cosmofly
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 8:25 pm

From the chart, Airbus says NEO is 12% better than MAX. Boeing says NEO is the same as MAX. Simply take the average and we have NEO being 6% better than MAX.

GTF can be a game changer (besides the reserve rumored) while leapX really pushes the limit to leap. Even for NEO leapX vs Max leapX, the 748F case shows that the fan size difference of the GEnx2B seems to have taken a bigger penalty than GE has expected.

Riding on the failure of the recent 787 and 748 executions, I would say Boeing management needs more homework and needs to be much more diligent with MAX.
 
ikramerica
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 8:32 pm

Quoting cosmofly (Reply 26):
From the chart, Airbus says NEO is 12% better than MAX. Boeing says NEO is the same as MAX. Simply take the average and we have NEO being 6% better than MAX.

You say you are 100% smarter than me. I'm saying I'm 1100% smarter than you. So on average, maybe I'm only 500% smarter?
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Nicoeddf
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 9:19 pm

Quoting planewasted (Reply 23):
The A330 can can compete, and even beat the 777 on lots of routes. And the A330 has much smaller engines than the 777! Why would this not apply to the A320NEO vs 737MAX?
Quoting SASMD82 (Reply 24):
And again, I agree! The A330-300 is actually superior to the B777-200(ER) for basically all the missions up to 8 or 9 hours.

Sorry guys - totally false logic. The a320 and the 737 are equal or next to equal in seating capacity, range, purpose, mission profile. They use basically the same range of engine thrust.

Therefore, a smaller engine with less bypass ratio hinders efficiency on the 737.

On the other hand, the 777 and the 330 are for different missions. The 777 is bigger and due to the huge range advantage it features, it also is a lot heavier, necessitating a engine with more thrust (bigger!). The 330 COULD have a bigger engine, but it already has the most efficient engine of that generation with the appropriate size for its weight.

The 737 engine has NOT the optimal size...
 
abibus
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 11:09 pm

First how can some of you compare the neo with the max if we do not have any info o lets say real info about the max??? How can you give the 739 max already as the winner against the 321 neo ??? Lets wait for real numbers from Boeing and airbus and second is it not the easiest way to Find out wich plane burns really more fuel to let them fly the same day the same route with same number of pax and load??? I do not understand why A or B would have a benefit compareing not with real numbers airlines are not stupid
 
cosmofly
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 11:36 pm

Quoting ikramerica (Reply 27):
You say you are 100% smarter than me. I'm saying I'm 1100% smarter than you. So on average, maybe I'm only 500% smarter?

If you can back up the claims with substance, you are probably not far from the truth.


I am only pointing out the probability here and the face value obviously favors the NEO.
 
travelhound
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 11:41 pm

Quoting RoseFlyer (Reply 14):
How often do 737s and A320s actually fill their tanks to their max capacity? I was under the impression that range is rarely limited on fuel capacity.

Yes, but I think the greater the range advantage the NEO has over the classic the greater its chances of becoming a worthy 757 replacement.

Quoting nicoeddf (Reply 28):
Therefore, a smaller engine with less bypass ratio hinders efficiency on the 737.

Just for reference the change in nacelle diameter from 61" to 68' on the 737 represents a 11.5% increase. For the CFM offering on the A320 the change from 68" to 78" represents an increase of 14.7%.

If using fan diameters alone and with the A320 representing the benchmark of 15% fuel efficiency gain, this metric results in the 737 being 11.3% more efficient. Funny enough this is what Boeing is currently quoting.

Now I know my metric is not perfect and that fuel efficiency as a percentage of fan diameter is not a linear equation, but it does give us an idea that numbers being quoted are in the realm of being realistic
 
ikramerica
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RE: Details&numbers About 737MAX And A320NEO

Wed Oct 12, 2011 11:49 pm

Quoting cosmofly (Reply 30):
If you can back up the claims with substance, you are probably not far from the truth.


I am only pointing out the probability here and the face value obviously favors the NEO.

Not really. My point was that without anything but marketing claims, and nothing to back it up, saying that you can average the claims and arrive at the truth is a fallacy. How do we know if Boeing is not being more liberal with their assumptions than Airbus, and it's really exactly as Airbus says? 6% would then only be 1/2 as wrong as 12%, not reality.

We don't know and can't know until we get some solid specs and engine tests.
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JoeCanuck
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 12:50 am

Quoting rheinwaldner (Thread starter):
Quote:
The controversy might be summed it with this question: If CFM had to upsize the fan on the LEAP to be competitive with the GTF on the neo, how can it now downsize the fan for the MAX and achieve the same result?

This is my favorite bit...I find it ironic that they are playing the bigger fan is better card when they are essentially doing the same thing for the 350-1000.

They claim they can get more power and the same efficiency with a bigger core and the same size fan as the -900 engine, just by spinning the fan faster.

So if the -1000 will get more power and the same efficiency out of the XWB engine with the same fan size as the 900, why is it so impossible to believe that CFM can get the same efficiency from a smaller fan with the same power engine?

On one hand, Airbus is saying more efficiency only comes with a bigger fan and on the other, they say they don't need a bigger fan to maintain efficiency while producing more power.

Two sides of the same coin...but they can't have it both ways.
What the...?
 
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 1:48 am

Quoting JoeCanuck (Reply 33):
They claim they can get more power and the same efficiency with a bigger core and the same size fan as the -900 engine, just by spinning the fan faster.

Pratt did that with the PW4098. Worked great!   

Ok, seriously a new very efficient core will bring efficiency to an engine. That is what Pratt tried to do with the PW4098. The idea was the PW4098 would burn at EIS 2% less fuel than an improved PW4090. Instead, it was 2% more fuel. Oops.

It is much easier to work with propulsive efficiency.

Lightsaber
"They did not know it was impossible, so they did it!" - Mark Twain
 
baroque
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 2:08 am

Quoting JoeCanuck (Reply 33):
So if the -1000 will get more power and the same efficiency out of the XWB engine with the same fan size as the 900, why is it so impossible to believe that CFM can get the same efficiency from a smaller fan with the same power engine?

Well, where to start? The higher thrust XWB will have a larger core for higher mass flow, but expect some interesting redistribution between fan and core. Somewhere that I do not seem to be able to find this morning (after an early morning start) but well noted in at least one a.net thread, it was made clear (?FG, but where is the article??? when the new larger XWB version was announced, some compromise was noted for TSFC, that is it would be slightly lower. So maybe the higher thrust TXWB rather proves the original point than presents a conflict.
 
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 3:45 am

Quoting Baroque (Reply 35):

Well, where to start? The higher thrust XWB will have a larger core for higher mass flow, but expect some interesting redistribution between fan and core. Somewhere that I do not seem to be able to find this morning (after an early morning start) but well noted in at least one a.net thread, it was made clear (?FG, but where is the article??? when the new larger XWB version was announced, some compromise was noted for TSFC, that is it would be slightly lower. So maybe the higher thrust TXWB rather proves the original point than presents a conflict.

Well, the numbers are 15% more power from the same sized fan. I don't think they were predicting a 15% reduction in SFC since they are still saying that they will have a 25% improvement over the nearest competitor...which I presume is the 77W.

So, the way I read it, they'll get lots more power from the same sized fan and probably not suffer the the same percentage drop in SFC.

Here's the story;

http://www.flightglobal.com/news/art...m-commonality-with-sisters-358742/

Quote:
The manufacturer will not increase the fan size, but will spin it 6% faster and alter the internal aerodynamics - shaping the inner annulus at the hub - to draw a larger airflow through the same intake.

It is scaling up the core with an annulus which is 3-4% larger. Among the efficiency measures are a dual microstructure technique implemented in turbine manufacture that enables the properties of the engine discs to differ in line with the differing temperatures at the hub compared with the rim.

So they make a larger core and compensate for the smaller fan by spinning it faster, maintaining bypass ratio. No mention of a drop in SFC.

ATW reported this:

http://www.aviationweek.com/aw/gener...18_2011_p0-337881.xml&channel=comm

Quote:
The higher performance for the TrentXWB powering the A350-1000 will come with “absolutely no fuel burn deterioration” over what was promised, says Mark King, the Rolls-Royce president for civil aerospace. The upgrade is built around better than expected performance on early build TrentXWB-84s for the -900, allowing the engine maker to tweak the performance. Some program details are still being defined, King says, but the size of the core will be scaled up slightly to increase air flow. What is more, the heat management will be improved and the new version also will showcase improved materials and tip clearance control. The fan will remain 118 inches in diameter.

Maybe they are just saying RR can do it and CFM can't.
What the...?
 
rheinwaldner
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 8:07 am

Quoting Stitch (Reply 18):
then it is not a surprise Airbus is using longer stage lengths.

Airbus does not use any specific stage lengths anymore. They have outlined their product on any range.

Quoting ikramerica (Reply 19):
Is Airbus going to show in their numbers the most favorable comparison for Boeing? I wouldn't expect them to.

Airbus, in this briefing, brings transparency and simply shows the whole package. They don't pick just one favourable range, they reveal the fuel burn over any range.

Sorry, guys, the excuse "we only have selective data from the manufacturers that put the best light on their product, we can't work with it!" no longer works!
In a quite a detailed way Airbus points out the difference between the current and the re-engined NB's. Their message concentrates on fuel reduction because that is the difference.

Quoting ikramerica (Reply 19):
It's as much propaganda as the Boeing numbers are.

The article clearly shows how Boeing derived their stunning numbers. And we have to admit that they accidentally forgot or ignored a number of factors to come to their distorted conclusion.

Based on these data I have asked whether somebody could disclose the "trick" on Airbus' side. But nobody answered honouring the detailed data that we got now. Just saying "A is just bending the truth in the opposite direction" is not enough. Show me where! A very detailed analysis lays on the table. Pick it to pieces!

Boeing's pants are down. And Airbus'? Show me the scale and the specific origin of their truth-bending...

If it is there you must be able to point it out. So far you make me believe it is not there (the trick on Airbus' side)...

Quoting RoseFlyer (Reply 20):
I think that's why Airbus numbers are showing fuel burn while Boeing numbers show trip by seat and total operating costs.

No, Boeing did show fuel burn as well. And figuring out how block fuel translates into fuel per seat should not be beyond the capabilities of this forum. And likewise to pick fair and comparable seatcount's to do that.

Quoting RoseFlyer (Reply 20):
They both show what makes their models look best and avoid even comparisons.

That is clear, but we can iron out their bias and get a clear picture. A lot of data has been given to work with. It seems like Boeing (& fans) shy the light. The blurred perspective has helped the 737MAX so far.

But eventually the truth will be inked into the order-books. Based on this data I say, that the 737 market share will sink. 40-60 could be realistic over some time.

Quoting RoseFlyer (Reply 20):
I think that's why Airbus numbers are showing fuel burn while Boeing numbers show trip by seat and total operating costs.

1. The total operating cost of an 737 and a A320 are known. The new, re-engined NB's will not change a lot. They will have impact on and improve a limited set of parameters. Airbus simply specifies what changes. This is the fairest and most precise metric.

2. The total operating cost depends so much on airline-specific-variables that they are useless for almost anything except to camouflage deficiencies.

Quoting abibus (Reply 29):
First how can some of you compare the neo with the max if we do not have any info o lets say real info about the max???

It is not true that we don't have info on the 737MAX.

Boeing gave plenty of it. In fact the article even painstakingly lists the history and evolution of all published figures by Boeing.

Boeing has made bold claims about their 737MAX. Do you say that they don't know what they want to achieve? Boeing (and even Airbus, as I believe) know within small parameters how good the 737MAX will be (exatly this is even mentioned in the article!). Let's give Boeing the credit that they are working with serious numbers while trying to aquire customers for the 737MAX.

Quoting JoeCanuck (Reply 33):
This is my favorite bit...I find it ironic that they are playing the bigger fan is better card when they are essentially doing the same thing for the 350-1000.

It is not the same thing because they don't shrink a GE90 for the A351.

A newly designed engine, that is smaller than the GE90, does not match it because size doesn't matter but because the new technology overcomes the disadvantage of being smaller. The LEAP engines on the 737MAX and the A320NEO will have the same technology however (far smaller difference than between Trent XWB and GE90).
 
flipdewaf
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 9:45 am

Quoting travelhound (Reply 31):
Just for reference the change in nacelle diameter from 61" to 68' on the 737 represents a 11.5% increase. For the CFM offering on the A320 the change from 68" to 78" represents an increase of 14.7%.

If using fan diameters alone and with the A320 representing the benchmark of 15% fuel efficiency gain, this metric results in the 737 being 11.3% more efficient. Funny enough this is what Boeing is currently quoting.

Now I know my metric is not perfect and that fuel efficiency as a percentage of fan diameter is not a linear equation, but it does give us an idea that numbers being quoted are in the realm of being realistic

That sounds like a fairly good reasoning behind a good guess to me.

Being is claiming ~12% better fuel burn and are using a ~12% bigger fan.

Airbus claims ~15% better fuel burn coming from the engine and has ~15% bigger fan.

It is not a perfect metric but looks good to me.

Fred
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JoeCanuck
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 10:35 am

Quoting rheinwaldner (Reply 37):
Quoting JoeCanuck (Reply 33):
This is my favorite bit...I find it ironic that they are playing the bigger fan is better card when they are essentially doing the same thing for the 350-1000.

It is not the same thing because they don't shrink a GE90 for the A351.

A newly designed engine, that is smaller than the GE90, does not match it because size doesn't matter but because the new technology overcomes the disadvantage of being smaller. The LEAP engines on the 737MAX and the A320NEO will have the same technology however (far smaller difference than between Trent XWB and GE90).

Um...says who? Far different in what respect? The comparison is between the -900 T-XWB and the -1000 version, and the LeapX offerings...engines in the same model line.

Why you bring the GE90 into the mix is beyond me. Neither engine model line has any relation to the GE90, except for the maker of the engines.

RR says that they can get more power with the same efficiency out of two engines using the same size fan.

CFM says they can get the same efficiency out of two engines using different sized fans.

In both cases, there will be a difference in fan size in relation to power within the SAME engine line. RR is changing the core in relation to the fan size and CFM is changing the fan size in relation to the core. What they are both changing is the core/fan size ratio.

If there is such a difference, I can't see it...perhaps you can share the formulas you base your conclusions on. I'm basing mine on what the engine makers themselves have said.

Both CFM and RR say they can get the same efficiencies out of both of their engines, so if you believe one, it would seem very odd that you wouldn't believe both.

Regardless of what one chooses to believe, this came from Airbus so any comparison of their products in relation to their competitors really should be taken with a huge lake bed of salt. I would be somewhat shocked if Airbus was to paint their own product in an interior light.

It's a sales brochure, folks.

By the way, to head off those who might wish to deposit my opinions in the fanboi bin, I don't give Boeing statements any more credence when they talk about Airbus.

[Edited 2011-10-13 03:42:41]

[Edited 2011-10-13 03:47:56]
What the...?
 
rheinwaldner
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 11:28 am

Quoting JoeCanuck (Reply 39):
The comparison is between the -900 T-XWB and the -1000 version

The Trent XWB for the 1000 is smaller than for the 900?
 
travelhound
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 12:28 pm

Quoting rheinwaldner (Reply 37):
But eventually the truth will be inked into the order-books. Based on this data I say, that the 737 market share will sink. 40-60 could be realistic over some time.

At the end of the day the superior aircraft will come at a premium and the inferior aircraft will be discounted. On a life cycle cost basis a $2-3 million dollar discount represents 1-2% in cost savings. When you throw in lower capital requirements or ROI into the mix the numbers become even more interesting.
 
JoeCanuck
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 12:41 pm

Quoting rheinwaldner (Reply 40):
The Trent XWB for the 1000 is smaller than for the 900?

Is it? I hadn't heard that. I have no idea how the line you quoted;

Quoting rheinwaldner (Reply 40):
Quoting JoeCanuck (Reply 39):
The comparison is between the -900 T-XWB and the -1000 version

...actually says that.

What RR has said, (and I have repeated), is that they plan a significantly higher thrust for the -1000 engine using the same size fan as the -900 engine, without sacrificing sfc on the -1000.

So higher thrust, same size fan, no loss in sfc.

So since it seems to be popular to categorize efficiency based solely, (or significantly), on fan size, it seems RR has found a way to buck that trend.

My postulation is if RR has figured out a way to do it, maybe CFM has too.

[Edited 2011-10-13 05:44:22]
What the...?
 
rheinwaldner
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 12:44 pm

Quoting JoeCanuck (Reply 39):
I would be somewhat shocked if Airbus was to paint their own product in an interior light.

It seems they don't have to, because possibly (I hardly dare to say) because they are not inferior. At least nobody was able to explain me where Airbus would have cheated...
 
JoeCanuck
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 12:50 pm

Quoting rheinwaldner (Reply 43):

Airbus, in that very diagram admits they have a different interpretation than Boeing so obviously, not everyone agrees.

I, in fact, have pointed out where Airbus may have contradicted themselves.

But, hey, it's your thread...you get to dare to say pretty much anything you wish.
What the...?
 
sirtoby
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 12:59 pm

Quoting flipdewaf (Reply 38):
Quoting travelhound (Reply 31):
Just for reference the change in nacelle diameter from 61" to 68' on the 737 represents a 11.5% increase. For the CFM offering on the A320 the change from 68" to 78" represents an increase of 14.7%.

If using fan diameters alone and with the A320 representing the benchmark of 15% fuel efficiency gain, this metric results in the 737 being 11.3% more efficient. Funny enough this is what Boeing is currently quoting.

Now I know my metric is not perfect and that fuel efficiency as a percentage of fan diameter is not a linear equation, but it does give us an idea that numbers being quoted are in the realm of being realistic

That sounds like a fairly good reasoning behind a good guess to me.

Being is claiming ~12% better fuel burn and are using a ~12% bigger fan.

Airbus claims ~15% better fuel burn coming from the engine and has ~15% bigger fan.

Sorry, but this is a completely wrong metric - a very much better metric is the area of the fan:
PI* [D_Fan(outer)^2 -D_Fan(inner)^2]
 
baroque
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 1:14 pm

Just keeping repeating it does not make it true. TSFC is expected to be lower for the higher thrust variant.

The manufacturer will not increase the fan size, but will spin it 6% faster and alter the internal aerodynamics - shaping the inner annulus at the hub - to draw a larger airflow through the same intake.

It is scaling up the core with an annulus which is 3-4% larger. Among the efficiency measures are a dual microstructure technique implemented in turbine manufacture that enables the properties of the engine discs to differ in line with the differing temperatures at the hub compared with the rim.

The empty weight of the aircraft will increase by 2.4 tonnes, of which each engine will contribute 250kg (550lb), although Rolls-Royce is planning a weight-reduction programme in the fan.


So from that we know it is a different annulus, Fan is faster and annulus is different. Different conditions, and apparently less optimum for TFSC and better for thrust. Engines each 250 kg heavier - that sounds like a spot of hardware to me.

From:

A350-1000 TrentXWB Gets 5,000lbs Extra Thrust Pt 1 (by PolymerPlane Jun 5 2011 in Civil Aviation)
there is this as background:

Down, up, and now up again in terms of thrust seems to be the history.

http://www.flightglobal.com/articles...hrust-values-following-weight.html
However, A350 programme chief Didier Evrard now confirms that the thrusts were tweaked at definition freeze "following the weight increase". Nominal thrust ratings for the -800, -900 and -1000 variants have each had a 1,000lb (4.5kN) increase to 75,000lb, 84,000lb and 93,000lb, respectively. Evrard says the change has had a "very marginal" impact on fuel burn and operating cost assumptions.

This is the second thrust adjustment for the A350. In 2007, Airbus revealed reductions in nominal thrust values of between 1,000lb and 4,000lb for each variant.

And this - which I think is what I had been looking for:
Stitch From United States of America, joined Jul 2005, 22035 posts, RR: 76
Reply 84, posted Mon Jun 6 2011 17:29:23 your local time (4 months 1 week 18 hours ago) and read 12759 times:

Lightsaber offered some comments on a higher-thrust Trent XWB that I saved:

He noted that RR could change the blade materials of the high and mid turbine, though he believes RR is already on the bleeding edge with the current engine, so new materials may not be readily available.

With the mid-turbine change, the low pressure compressor would have to have the airflow increased, to allow more fuel burn, as well as improvements in the low turbine and high pressure compressor.

He thought RR's comments on increased thrust would raise fuel burn could mean that the 93K Trent XWB is being pushed to the cooling limits of the turbine. To cool the turbine, RR might need to increase fuel flow into the engine (raising fuel burn) or increase the cooling air into the turbine, reducing efficiency.


That is, nobody who has looked into the matter supposes that the thrust increase for the TXWB without increasing fan diameter is not associated with an increase in fuel consumption. More in the rest of the thread.

These threads are in the twilight zone where a.net search does not seem to function. I cannot easily find the original Lightsaber post although I remember it in outline. But Stitch's summary explains the consequences of the various changes.

I await someone posting a similar explanation of how the Leap engine can maintain SFC while reducing fan size. Sure the fan can be turned faster - always assuming that the speed for the A32x sized engines permits this - but then you run into the same cascade of other changes you need to make. And the speed increase would have to be formidable, so probably not THAT much faster. They do not accept the weight penalty of large diameter fans just for fun.

[Edited 2011-10-13 06:39:29]
 
JoeCanuck
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 1:16 pm

Quoting sirtoby (Reply 45):

As Airbus is claiming with their XWB's, fan size is not the only determiner of power or efficiency. It seems neither diameter or area tells the whole story.
What the...?
 
flipdewaf
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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 1:22 pm

Quoting sirtoby (Reply 45):
Sorry, but this is a completely wrong metric - a very much better metric is the area of the fan:
PI* [D_Fan(outer)^2 -D_Fan(inner)^2]

On a basic level propulsive efficiency scales with fan diameter and not fan area, do the maths, you'll see.

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RE: Details&numbers About 737MAX And A320NEO

Thu Oct 13, 2011 2:05 pm

Quoting SASMD82 (Reply 24):
And again, I agree! The A330-300 is actually superior to the B777-200(ER) for basically all the missions up to 8 or 9 hours.

Which is why the 77W is the 777 model that is selling like hotcakes.

As to the 737MAX vs. the A320NEO, I suspect that we will not have any realistic comparisons until both are a lot farther along then they are now. I suspect that most A320 customers will order the A320NEO, and most 737 customers will order the 737MAX. There will be a battle at those airlines that operate both (DL, UA in particular) but we will not get any defections until more concrete information. What is known now is that the 737 and A320 are very, very close in overall capability and economics, and they will most likely remain so. It is also clear that Boeing has a harder path to get the same gain as Airbus, because Airbus does not have engine diameter limitations and they do not already have winglets, while Boeing does have winglets now and has serious problems with engine diameter. But we will not really know if they are going to be equal until we see what emerges. Boeing also has a potential disadvantage in that they are putting all of their bets on one engine, while Airbus has the choice of two. My conclusion is that IF Boeing does everything right they should be able to maintain parity, but have no chance of gaining on the NEO unless Airbus pulls a major flub (which I would not expect.) They are also going to have to spend a lot more than will Airbus. I believe they realize this, and is why they were so enamored (as was I) with the idea of an all-new aircraft. My take on why they did not go that route is that they felt they could not withstand the 3 to 5 years where they would not have a competitive airplane, and with the experience of the 787 staring them in the face they could not guarantee that there would not be another major delay, which would have been disastrous.
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