rheinwaldner
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Doubts About The Engine Of The MAX

Wed Apr 11, 2012 3:37 pm

The following article with the title "Even more doubts about B737MAX" has some detailed and recent information about the upcoming NB engines:
http://aeroturbopower.blogspot.com/2...en-more-doubts-about-b737max.html:

Quote:
"The end result is that you've got a really big gap between a P&W Neo and a CFMi Neo." To clarify: the gap is in favor of the P&W GTF and Airline Economics is quoting an senior industry expert here, who expects the LEAP to have a 4% disadvantage.

Comment: 4% might be at the upper end for the engine alone. But bundled with the disadvantage of the tricky engine installation on the MAX this gap could even become larger in total.

Other (almost weird) info from the article:

- CFM in an attempt to get market share in 2011 fought extreme price battles. They went so low that one customer is reported to have picked the GTF just by applying the principle "what is good, can't be cheap" (because the LEAP was offered at a suspiciously low price).

- The GTF on the MAX might become an option.

- There also seems to be much talk that the lack of MAX commitments might have to do with real deficits of the MAX.

- Even the scenario where Boeing would have to rethink the MAX strategy is discussed (and considered as likely).

- The GTF seems to beat all promises.
 
MD-90
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 4:17 pm

Quoting rheinwaldner (Thread starter):

- The GTF seems to beat all promises.

I hope it's true--I was born in Connecticut and I'm a P&W fan.
 
chuchoteur
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 4:27 pm

Quoting MD-90 (Reply 1):
Quoting rheinwaldner (Thread starter):

- The GTF seems to beat all promises.

I hope it's true--I was born in Connecticut and I'm a P&W fan.

P&W are willing to offer performance guarantees.
That's all that matters really - if it doesn't deliver, they pay.

They've run that engine a lot of hours now, more than almost any other new engine design going into service, so their performance guarantees have substance I would say...
 
roseflyer
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 4:31 pm

First off aeroturbopower is probably one of the most pro-Airbus aviation blogs there is, so I do take the information with a little bit of apprehension as there typically is an obvious slant compared to Leeham, Scott Hamilton, Jon Ostrower, and Flight Global. Many of its posts sound more like an Airbus sales campaign than anything else. I'm not saying it is a bad blog, just one that shows bias.

I find it interesting that there are claims of 4% difference between the LeapX and PW GTF on the A320NEO. That is a big difference for a side by side comparison. If there was such a discrepency, I'd expect airlines to be very bias towards the GTF. The article's claim that CFMI slashing prices and making its engines virtually free is complete nonsense in my opinion. CFMI is a for profit company and is not selling engines virtually free to maintain market share. Anyone who thinks that is not a very knowledgeable because the overhaul and spares business on engines is not enough to slash prices to virtually free. CFM has about 40% of the A320 NEO market. To me that indicates that the GTF may be better. 4% is an interesting number.

One thing I find interesting is that it states "there is increasing evidence that the PW GTF is exceeding expectations in all aspects of testing". I'd be curious to learn more about that. It would be great for it to be exceeding expectations, although the line all aspects of testing makes no sense. If it exceeds all aspects of testing, then the expectations were not established correctly in the first place. One thing I learned early in my design engineering career is that if you find no failures in your testing, you overdesigned the product and there is more opportunity left. I'd like to learn more about that.

I find it interesting that the article comes up with the conclusion that Boeing is wrong with the 737MAX and they should go back to the drawing board.
If you have never designed an airplane part before, let the real designers do the work!
 
phxa340
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 4:33 pm

Quoting rheinwaldner (Thread starter):
There also seems to be much talk that the lack of MAX commitments might have to do with real deficits of the MAX.

My first issue with this post is that this is a blog .... not really an article. I can write whatever I want on a blog too ... until I see a customer cancel a MAX order because of a 4% short fall, it is all speculation.

Stitch can probably give you a more accurate number but doesn't that MAX have over 800 + commitments ?? That is a pretty solid number.

As far as the price battle - that almost made me laugh "whats good can't be cheap". Ask Ryanair how they feel about their rediculously cheap 737 order. I think they would use the word great.
 
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garpd
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 4:45 pm

Quoting rheinwaldner (Thread starter):
The following article with the title "Even more doubts about B737MAX" has some detailed and recent information about the upcoming NB engines:
http://aeroturbopower.blogspot.com/2...html:

I saw that post before you linked it here. That blog is glaringly Pro-Airbus and at times seems as if it is written someone after gulping down some Airbus brand 100% sugar Cool Aid.

People were dead certain Boeing was making a mistake launching the 737 NG with the same single engine manufacturer. Look how that turned out!

This blog post can be filed under "Irrelevant Fan-Boy post" IMO.

Quoting Roseflyer (Reply 3):

I find it interesting that the article comes up with the conclusion that Boeing is wrong with the 737MAX and they should go back to the drawing board.

What do Boeing know about making airplanes? Airbus are the pros and this blogger knows a lot. Boeing should listen to the both of them!
[/Scarcasm]
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nomadd22
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 5:00 pm

From the gearbox on the GTF being more efficient than Pratt had officially anticipated I had the feeling they were being conservative with their claims. Even with a 2% drop because of a smaller fan, I wondered about their exclusion from the Max.
The blog is a joke, but the fact remains that if Pratt can keep up with the other guys core wise, theyre going to have an advantage.
Anon
 
neutronstar73
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 5:14 pm

Quoting Roseflyer (Reply 3):

Absolutely. They are unabashed in their pro-Airbus, anti-CFM tirades. Only reason to read that site is for comedy. Aeroturbopower should not be taken seriously. If you do take it seriously, take it with a kilogram of salt, because I don't think I've ever read a "post" on that site that was in any way complementary to CFM or Boeing...ever.
 
roseflyer
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 5:41 pm

http://www.flightglobal.com/blogs/fl...reaking-boeing-reveals-new-73.html

I am not sure if these is just convenient timing, but flightglobal presented an article where Boeing reveals some real design parameters.

8'' nose extension
Fly by wire spoilers
Tail cone extension
Electronic Bleed Air control
Elevator strengthening

Flightglobal actually provides some facts unlike the blog which had a lot more speculation.
If you have never designed an airplane part before, let the real designers do the work!
 
PresRDC
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 6:02 pm

Quoting Roseflyer (Reply 3):
The article's claim that CFMI slashing prices and making its engines virtually free is complete nonsense in my opinion. CFMI is a for profit company and is not selling engines virtually free to maintain market share. Anyone who thinks that is not a very knowledgeable because the overhaul and spares business on engines is not enough to slash prices to virtually free.

Recall that, with the exception of spare engines, neither CFMI nor P&W sell engines directly to airlines. The engines are sold to the airframer at a price that is negotiated in a master contract for the specific engine model and does not change for different customers.

What engine manufacturers do, though, is offer credits for a percentage of the engine price that are issued directly to the airline and can, at the airline's option (an option that is usually taken), be converted to cash and wired directly to the airframer to help offset the cost of the aircraft. That percentage is highly negotiated and is typically well north of 65% of the price at which the engine is sold to the airframer.

Both P&W and CFMI offer performance guarantees. It is very much part of the business. Guarantees often include things like engine weight, fuel consumption, climb performance, maintenance cost, etc. The guarantees are typically expressed as rates on a fleet wide average (except for zero event guarantees, such as IFSD, remote site removal, uncontained failure, etc.) and are subject to the airline maintaining certain operating parameters (derate, stage length, etc.).
 
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Stitch
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 6:14 pm

Pratt is said to be holding back a number of percent in SFC on the PW1100G to protect themselves as they cannot afford another engine program that does not meet contractual guarantees. So it's not inconceivable that the PW1100G will be better than Pratt is currently stating.

As to LEAP-X and the MAX, airlines forced Boeing to launch it so they must have faith otherwise they'd have waited for the NSA with GTFs.

I believe Pratt's VP of GTF development was overly optimistic in his opinion that the PW1100G could fit on the 737NG with little to no modification to the airframe. I would not be overly surprised if Boeing's decision to sole-source the LEAP-X was due to the amount of production and design changes necessary to accommodate the PW1100G.
 
fpetrutiu
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 6:18 pm

Quoting PhxA340 (Reply 4):
Stitch can probably give you a more accurate number but doesn't that MAX have over 800 + commitments ?? That is a pretty solid number.

Over 1000 now per Boeing: http://boeing.mediaroom.com/index.php?s=43&item=2212
Florin
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Hamlet69
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 6:47 pm

Quoting rheinwaldner (Thread starter):
- The GTF on the MAX might become an option.

Weirdly, this is the only part of the blog that actually has some meat behind it.

At last month's ISTAT conference, there was a lot of talk that Boeing is still considering the GTF as a second option on the MAX. While Boeing has dismissed this publically, there seems to be a lot of respectable sources indicating that the GTF is indeed, at least being looked, with a final "yea or nay" decision expected to come sometime this summer.

Aspire Aviation adds a bit more to this in their recent article here:

http://www.aspireaviation.com/2012/0...ing-continues-to-optimise-737-max/

They mention the potential of a 71" fan for a 737 GTF. I do wonder at that, as from my sources, Boeing can fit up to a 70" before they 'run into issues'.

Guess we'll just have to wait and see. . .

Regards,

Hamlet69
Honor the warriors, not the war.
 
737tdi
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 7:15 pm

This has nothing to do with the engines but more with the last two posts.

Boeing best do something about the problems with the horizontal stabalizers on the NG v the Max, we are having a few problems with skin cracking on them. It's not a hard repair but takes the aircraft out of service for a couple of days. Maybe that is part of the "elevator strengthening"?
 
PlaneAdmirer
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 7:43 pm

Quoting Stitch (Reply 10):
Pratt is said to be holding back a number of percent in SFC on the PW1100G to protect themselves as they cannot afford another engine program that does not meet contractual guarantees. So it's not inconceivable that the PW1100G will be better than Pratt is currently stating.

While I know this is about the 737, the original post and yours made me think about the GTFon the 777NG. If the GTF is performing as well as rumored, then it may make the 777NG a very competitive offering for some time.
 
roseflyer
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 7:52 pm

Quoting 737tdi (Reply 13):

Boeing best do something about the problems with the horizontal stabalizers on the NG v the Max, we are having a few problems with skin cracking on them. It's not a hard repair but takes the aircraft out of service for a couple of days. Maybe that is part of the "elevator strengthening"?

If you are talking about the cracking and damage caused by the elevator tab system, there is an Airworthiness Directive published that you can read on the FAA website: 2010-17-19. That will all be fixed long before the MAX. AD's usually have a design change and Service Bulletin mandated in about 2 years time to fix the problems.
If you have never designed an airplane part before, let the real designers do the work!
 
737tdi
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 8:38 pm

Quoting Roseflyer (Reply 15):
If you are talking about the cracking and damage caused by the elevator tab system, there is an Airworthiness Directive published that you can read on the FAA website: 2010-17-19. That will all be fixed long before the MAX. AD's usually have a design change and Service Bulletin mandated in about 2 years time to fix the problems.




Not that, I was involved in changing all of our elevators. We were doing them on RON every Friday night for what seemed like forever. We got quite good at it, ours have been completed for quite some time. This only addressed the vibration and flutter of the elevator.

What I'm referring to is the lower horiz. stab skin. We are finding small lateral cracks between the ribs. Like stated they are easy to repair with a simple doubler but still take awhile to perform and costly downtime. Don't know if you have ever taken a 737CL or NG to high power but there is a very noticeable difference between the two in relation to stab vibration. I suspect it is due to the hard mounted engines on the NG v the isolator mounted on the CL.
 
rheinwaldner
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 8:40 pm

Quoting Roseflyer (Reply 3):
blogs
Quoting PhxA340 (Reply 4):
blog
Quoting garpd (Reply 5):
blog

This is nor fair. Because they talk about an article in a publication. In fact it is almost zero opinion from aeroturbopower in the blog post. And the opinion that is expressed favours Boeing.

Quoting PhxA340 (Reply 4):
I can write whatever I want on a blog too

But not quoting a publication.

Quoting garpd (Reply 5):
That blog is glaringly Pro-Airbus and at times seems as if it is written someone after gulping down some Airbus brand 100% sugar Cool Aid.

Show some examples. I cant remember.

Quoting neutronstar73 (Reply 7):
If you do take it seriously, take it with a kilogram of salt, because I don't think I've ever read a "post" on that site that was in any way complementary to CFM or Boeing...ever.

So you probably didnt read a post from them at all?

IMO the bias of the readers might have affected a balanced judgment as much as any other bias...
 
phxa340
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 8:56 pm

Quoting rheinwaldner (Thread starter):
This is nor fair. Because they talk about an article in a publication

It is very fair ... the 'article' comes from the "Blogspot"... This is neither a balanced reveiw nor based on facts , just guesses.

I am all for a healthy debate on the merits of the NEO and MAX but this is clearly biased to the point where it stopped being fun to read after the first few sentences.
 
roseflyer
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 9:12 pm

Quoting rheinwaldner (Reply 17):

Quoting garpd (Reply 5):
That blog is glaringly Pro-Airbus and at times seems as if it is written someone after gulping down some Airbus brand 100% sugar Cool Aid.

Show some examples. I cant remember.

How about the analysis of Delta ordering the 739ER and only comparing it to the A320NEO and A321NEO? That was almost comical bias. When someone tried to point out that a realistic comparison would be versus the A320 or A321, the blogger ignored it and said that since the competition will eventually be operating A320NEOs and A321NEOs, then it is the only logical comparison and the blogger completely ignored the savings of replacing 30 year old 752s with brand new 739ERs and the fact that Virgin America and jetBlue have A320s on order that they will be taking delivery of side by side with A320NEOs.

How about the multiple posts, doubts on MAX, GTF exceeds expectations, Ryanair criticism of the MAX, American and Norweigian defecting from Boeing, etc? It's not that I am selecting a few anti-Boeing and pro Airbus articles, it is that every post on that blog is like this.

Then of course there was the technical analysis of block fuel burn comparison of the A320 vs 738. It was based on ACAPs and conveniently chose the highest MTOW of the A320 vs the lowest fuel capacity restricted 738 and conveniently chose a range and payload that was exactly where the A320 had it's peak performance. That's like saying that the A319 burns less fuel than the A320 when the A320 is artificially limited to the amount of payload that an A319 can. Of course when you ignore the 30 seat advantage and increased payload, the A319 burns less fuel than the A320. However airlines in actualy operating conditions prefer the A320 and its lower CASM.

That blogger searches for anything negative about a Boeing or CFM product and posts it. That blogger also finds everything positive about the GTF and posts it. There are some general posts, but unless they are pointing out straight facts like airline X ordered an airplane or a certain model was launched, most of them follow the pattern. Reading that blog is like watching Fox News and trying to get an understanding of the democratic party's political objectives. Sure there are some facts in there, but a lot more facts that are positive about one side are presented while facts promoting the other side are ignored.

[Edited 2012-04-11 14:20:44]

[Edited 2012-04-11 14:37:39]
If you have never designed an airplane part before, let the real designers do the work!
 
PresRDC
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 9:51 pm

Quoting Stitch (Reply 10):
I would not be overly surprised if Boeing's decision to sole-source the LEAP-X was due to the amount of production and design changes necessary to accommodate the PW1100G.

The CFMI 737 contract with Boeing gives CFMI exclusivity on a re-engined 737 platform. That is why CFMI is sole source on that aircraft.
 
racko
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 9:59 pm

Quoting Roseflyer (Reply 8):
8'' nose extension

Are we talking a wart like on the A330F or a more elegant solution, i.e. a lengthened gear?
 
MountainFlyer
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 10:23 pm

Quoting racko (Reply 21):
Are we talking a wart like on the A330F or a more elegant solution, i.e. a lengthened gear?
This blog says landing gear.

[Edited 2012-04-11 15:27:10]
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CM
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RE: Doubts About The Engine Of The MAX

Wed Apr 11, 2012 10:42 pm

Quoting 737tdi (Reply 13):
Boeing best do something about the problems with the horizontal stabalizers on the NG v the Max

The stab skin cracking issue is already solved and is either being delivered on new 737NGs today, or will begin delivery on new aircraft shortly. It is not something which will need to wait for the MAX.

Quoting racko (Reply 21):
Are we talking a wart like on the A330F

No. The nose gear doghouse is being enlarged (lengthened forward) so the longer gear does not have to extend below the current skin lines. There may be some small blisters incorporated into the NLG doors to accommodate the required space around the tires for a flailing tread, but there will be no A330F-style "box" hanging below the fuselage.
 
neutronstar73
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 3:30 am

Aeroturbopower is comical in its bias. I swear, I've never read a single article on that "website" that was NOT biased in favor of Airbus or didn't make jabs at GE or CFM. That blog has a ridiculously high Airbus and Rolls Royce bias.

At least from my perspective.
 
PlanesNTrains
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 4:30 am

Quoting rheinwaldner (Reply 17):
IMO the bias of the readers might have affected a balanced judgment as much as any other bias...

Well, that knife cuts both ways, now doesn't it?  

-Dave
-Dave
 
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lightsaber
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 7:06 am

I find the blog's bias amusing. Pratt did hold 4% TSFC in reserve. However, they are not there yet. They shouldn't be expected to be there now either. But Pratt didn't change the fan for the fun of it.    That is expensive! It was to improve performance.

Now the interesting time will be this summer when Pratt optimized the PW1500G in the air. Until the compressors and variable area nozzle are co-optimized... There will be room to improve the engine. But while ground state optimization have been performed, the GTF is unusually dependent upon its nacelle for performance. This was partially true with the 787 and will be very true with the A350 in that the nacelle has more impact on TSFC than before. This is just the trend.

Quoting PresRDC (Reply 9):
Recall that, with the exception of spare engines, neither CFMI nor P&W sell engines directly to airlines. The engines are sold to the airframer at a price that is negotiated in a master contract for the specific engine model and does not change for different customers.

But as you know, there are rebates, guarantees, parts prices, and other aspects. Some are as good as a price cut.

Quoting Stitch (Reply 10):
Pratt is said to be holding back a number of percent in SFC on the PW1100G to protect themselves as they cannot afford another engine program that does not meet contractual guarantees. So it's not inconceivable that the PW1100G will be better than Pratt is currently stating.

It should be 4%. However, expect only 1% at EIS with the remainder 'brought in' within 3 or so years.

Quoting Hamlet69 (Reply 12):
While Boeing has dismissed this publically, there seems to be a lot of respectable sources indicating that the GTF is indeed, at least being looked, with a final "yea or nay" decision expected to come sometime this summer.

I have not heard this. If true, it will be interesting to know the contract provisions on how Pratt could put the GTF on the MAX. I suspect this is only rumor.

Lightsaber
"They did not know it was impossible, so they did it!" - Mark Twain
 
sirtoby
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 7:36 am

Quoting neutronstar73 (Reply 7):
Absolutely. They are unabashed in their pro-Airbus, anti-CFM tirades.
Quoting Roseflyer (Reply 19):
That blogger searches for anything negative about a Boeing or CFM product and posts it.

At least, I found that one, saying a lot of positive things abut the 787 vs. the A330.

http://aeroturbopower.blogspot.com/2...amliner-ready-to-fly-and-kill.html
 
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Faro
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 10:48 am

Quoting rheinwaldner (Reply 17):
Quoting Roseflyer (Reply 3):
blogs
Quoting PhxA340 (Reply 4):
blog
Quoting garpd (Reply 5):
blog

This is nor fair. Because they talk about an article in a publication. In fact it is almost zero opinion from aeroturbopower in the blog post. And the opinion that is expressed favours Boeing.

  

Read the article people. If they have displayed a certain bias in some of their prior articles, does that mean that every single article will be biased?

This one clearly is more objective and very very interesting. Read, don't bleat.

Faro
The chalice not my son
 
travelavnut
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 12:02 pm

Quoting neutronstar73 (Reply 24):
Aeroturbopower is comical in its bias

Haha!! Pot, meet Kettle   

Quoting Hamlet69 (Reply 12):
Quoting rheinwaldner (Thread starter):
- The GTF on the MAX might become an option.

Weirdly, this is the only part of the blog that actually has some meat behind it.

I hope this actually comes to fruition. I really have a soft spot for P&W  
Live From Amsterdam!
 
rheinwaldner
Topic Author
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 12:26 pm

Quoting Roseflyer (Reply 8):
I am not sure if these is just convenient timing, but flightglobal presented an article where Boeing reveals some real design parameters.

I have noticed the articles about this. But the published information seems not to be new. IIRC these things have been mentioned beforeby Boeing .

Quoting Stitch (Reply 10):
I would not be overly surprised if Boeing's decision to sole-source the LEAP-X was due to the amount of production and design changes necessary to accommodate the PW1100G.

This seems to be correct, IMO.
It seems like squaring the circle to mount a huge fan to the 737. And the huge fan is the essential feature of the GTF. In fact the GTF is primarily invented to raise the fansize without getting in troubles with too much speed at the fan tips.

Quoting PhxA340 (Reply 18):
It is very fair ... the 'article' comes from the "Blogspot"... This is neither a balanced reveiw nor based on facts , just guesses.

The article does not come from the blogspot. It quotes experts that have made statments at ISTAT.

Quoting Roseflyer (Reply 19):
How about the analysis of Delta ordering the 739ER and only comparing it to the A320NEO and A321NEO?

Strange, I admit.

Quoting Roseflyer (Reply 19):
How about the multiple posts, doubts on MAX, GTF exceeds expectations, Ryanair criticism of the MAX, American and Norweigian defecting from Boeing, etc?

Ok, about these things you can report without any bias by just stating the truth and yet for a Boeing fanboy it must sound like biased junk. I don't know how to write about these things in a balanced way and without questioning Boeing's position at the same time.

Quoting Roseflyer (Reply 19):
Then of course there was the technical analysis of block fuel burn comparison of the A320 vs 738.

Derailing Boeings claims about the NG is really not complicated and does neither require bias nor twisted numbers. Any analysis that shows these two aircraft to be more or less on par is probably closer to the truth than the challenged numbers from Boeing PR.

Quoting PlanesNTrains (Reply 25):
Well, that knife cuts both ways, now doesn't it?
-Dave

Fair remark.
I am the voice that has "told you so", in case the future will show that the MAX will not be the last response to the NEO from Boeing. If not, I will admit that I was wrong.

I have always said that:

- The 737 is penalized significantly by the design heritage from the 60. It is a lifecycle handicap. The 737 did extremely well and had an extremely long run. One day it will be inadequate to cope with the future's requirement. I just say this is now. The quoted 4t weight gain, as leaked by SUH at ISTAT, might underline this.

- In our area we judge technical solutions in these two areas: "fit for purpose" and " fit for future". The 737 would only qualify for the former and not for the latter IMO. The A320 does qualify for both.

- It will take some miracolous effort from Boeing's side to keep parity while taking the 737 for another round.

- The focus on the new GTF/high b/r engines for the next round exactly hits the 737 at its weakest point (ground clearance).

- Boeings is now going too far, in attempting to keep contact with two newer models by upgrading two older designs. I dare to say that they won't keep their today 737&777 customers that way (notice this is not the same like saying: I wish that they won't keep their customer, because this is clearly not what I wish. A fanboy would wish Boeing to suffer. This is not my position. Not at all. I try to be a balanced commentor).

Quoting lightsaber (Reply 26):
So it's not inconceivable that the PW1100G will be better than Pratt is currently stating.
It should be 4%. However, expect only 1% at EIS with the remainder 'brought in' within 3 or so years.

So our Pratt expert here basically backs up the main claim of the article.

Quoting PhxA340 (Reply 18):
I am all for a healthy debate on the merits of the NEO and MAX but this is clearly biased to the point where it stopped being fun to read after the first few sentences.

So debate with lightsaber about the 4%.

I would add that these 4% seem not to be the gap between the Leap and the GTF. IIRC it has been reported that even defensive estimations for the GTF would reveal a gap to the Leap. And these 4% seem to be just the gap between the safely estimated and the more and more realisticly to be expected capability of the GTF. Which would lead to an even larger gap between this emerging wonder-GTF and the Leap.
 
Daysleeper
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 1:59 pm

Quoting Roseflyer (Reply 3):
First off aeroturbopower is probably one of the most pro-Airbus aviation blogs there is,
Quoting garpd (Reply 5):
That blog is glaringly Pro-Airbus and at times

This being the first blog I’ve read from this author I’ve no idea to his bias, but it’s certainly not the first time I’ve read about Pratt holding back the true potential of the GTF.

Quoting lightsaber (Reply 26):
Quoting Stitch (Reply 10):Pratt is said to be holding back a number of percent in SFC on the PW1100G to protect themselves as they cannot afford another engine program that does not meet contractual guarantees. So it's not inconceivable that the PW1100G will be better than Pratt is currently stating.
It should be 4%. However, expect only 1% at EIS with the remainder 'brought in' within 3 or so years.

If this is indeed the case, then it’s going to put Boeing in a very difficult spot. We already know that that updating the engine on the 737 is much more involved than on the A320, with both the airframe and engine requiring significant modification costing both time and money.

A 4% difference has the potential to be a real game changer, but the question is; what can Boeing do about it? Pratt have no motivation to guarantee anything more than they have already so hypothetically Boeing could offer a GTF-Max tomorrow and then spend 2 years and vast amounts of cash developing it only for the 4% to never materialise.

The problem then is, what happens if the GTF does turn out to have a 4% advantage, by the time this will be confirmed the Max will likely be in testing if not in service – too late for Boeing to do anything about it, other than re-max the max.

A little OT, but as an added bonus for Airbus. Should this turn out to be correct, then the GTF powered A321NEO will be an absolutely perfect 757 replacement.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 2:57 pm

Quoting garpd (Reply 5):
People were dead certain Boeing was making a mistake launching the 737 NG with the same single engine manufacturer. Look how that turned out!

Look how the 787 turned out. The GENx was late and under performing, but the RR was doing better. Putting all your money on one square might pay off better, but it can make your losses bigger, too.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 3:00 pm

Quoting rheinwaldner (Reply 30):
One day it will be inadequate to cope with the future's requirement. I just say this is now. The quoted 4t weight gain, as leaked by SUH at ISTAT, might underline this.

Daniel Tseng's sources at Boeing have stated that SUH is wrong and the real weight gain is much smaller.



Quoting Daysleeper (Reply 31):
The problem then is, what happens if the GTF does turn out to have a 4% advantage, by the time this will be confirmed the Max will likely be in testing if not in service – too late for Boeing to do anything about it, other than re-max the max.

If lightsaber is correct, that 4% likely won't become available until after 2020. CFM won't be standing still themselves during that time and that fuel burn advantage will have it's greatest impact on longer stage lengths. And the A320 already has the advantage on long stage lengths compared to the 737NG, and yet the 737NG is still in that fight thanks to a 2000 liter greater fuel load that allows it to at times outfly the A320-200 when winds are adverse.

So should the PW1100G gain all 4%, that will favor that engine on the A320-200 and (especially) A321-200 on longer missions. Might actually make the A321-200neo a true 757-200 replacement in terms of nominal range.

But Boeing will surely still sell plenty of 737MAXs for shorter missions and will probably still score some orders with long-distance carriers, as well, since the MAX will load even more fuel than the NG.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 3:08 pm

Quoting PhxA340 (Reply 18):

It is very fair ... the 'article' comes from the "Blogspot"... This is neither a balanced reveiw nor based on facts , just guesses.

I am all for a healthy debate on the merits of the NEO and MAX but this is clearly biased to the point where it stopped being fun to read after the first few sentences.

The article is in Aviation News, which is subscription only. We are relying on the blogger making fair quotes from the article, which he has read and we haven't. If the quotes are accurate, then Boeing has a problem.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 3:09 pm

Quoting Daysleeper (Reply 31):
The problem then is, what happens if the GTF does turn out to have a 4% advantage, by the time this will be confirmed the Max will likely be in testing if not in service – too late for Boeing to do anything about it, other than re-max the max.

The 737NGs being built today are ~ 10% more efficient that the ones built in the 90s. You can always make changes if there are shortfalls during production. I am still a big believer that the NEO is going to be the better plane for long distances and the MAX will have the advantages for short trips.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 3:29 pm

Quoting RickNRoll (Reply 32):
Look how the 787 turned out. The GENx was late and under performing, but the RR was doing better.

Both engines were late and the Rolls-Royce Trent 1000's initial SFC miss was said to be almost double that of the GEnx-1B. GE did have significantly more work to do to recover that miss, however.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 4:12 pm

Quoting travelavnut (Reply 29):
Haha!! Pot, meet Kettle

Please be gone. You add nothing to the thread, except a targeted name calling.

Meanwhile:

I think CFM knows the constraints they are up against. I'm sure Boeing does, too. I'm particularly interested to see how flight tests go with P&W and the MRJ GTF variant.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 4:23 pm

Quoting Stitch (Reply 33):
Quoting rheinwaldner (Reply 30):
One day it will be inadequate to cope with the future's requirement. I just say this is now. The quoted 4t weight gain, as leaked by SUH at ISTAT, might underline this.

Daniel Tseng's sources at Boeing have stated that SUH is wrong and the real weight gain is much smaller.

Sorry, Daniel Tseng does not nearly qualify to be in the same league as SUH. SUH knows what he knows because Boeing has told him so as potential customer. And SUH is not biased. His advice should be taken very seriously by Boeing.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 4:28 pm

Quoting rheinwaldner (Reply 30):
I would add that these 4% seem not to be the gap between the Leap and the GTF. IIRC it has been reported that even defensive estimations for the GTF would reveal a gap to the Leap. And these 4% seem to be just the gap between the safely estimated and the more and more realisticly to be expected capability of the GTF. Which would lead to an even larger gap between this emerging wonder-GTF and the Leap.

I am now really confused. The basis for the article was that the GTF is expected to have 4% advantage over the LeapX on the A320NEO according to an expert.

Now back to commenting on the actual article.

What I really call into question is that if this 4% is true, why are the orders for the GTF and LeapX split almost 50-50 on the NEO? It could be other factors such as reliability, maintenance, spares, support, etc. As an aside note, GTFs have been around for decades. They have only ever been used commercially in one application which was the BAE-146. That airplane suffered from engine reliability problems due to the complexity of the gearbox and all the cooling required with it. Such factors counteracted the efficiency benefits of a GTF. Technology has changed and PW hopes to have the winning combo to overcome some of the drawbacks of the GTF. When it comes to adding high speed moving parts to an engine, reliability is going to suffer, so that is just one possibility for why airlines may choose a LeapX even if there is an efficiency advantage there are other factors. This is all speculation on my part.

The article then talks about how the MAX is at such a disadvantage for not having the GTF. This is where I am seeing the bias in either Aeroturbopower or the quoted Airline Economics article. If all the Airbus customers were going for the GTF, then I would definitely understand the argument that Boeing made a poor decision by going LeapX only. However, Airbus appears to have parity between the two engines. The MAX does have some disadvantages with ground clearance, so I understand that they likely will not derive as much benefit from the new engines as Airbus will, however I am just stating that the claims of the LeapX being the wrong decision are not adequately justified. I am curious if a GTF is being considered for the MAX or not.
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 4:52 pm

Quoting Stitch (Reply 33):
If lightsaber is correct, that 4% likely won't become available until after 2020. CFM won't be standing still themselves during that time and that fuel burn advantage will have it's greatest impact on longer stage lengths. And the A320 already has the advantage on long stage lengths compared to the 737NG, and yet the 737NG is still in that fight thanks to a 2000 liter greater fuel load that allows it to at times outfly the A320-200 when winds are adverse.

Why would it be 2020? Final versions of the GTF are expected to be flying next year so in a best case scenario it’s would be reaching its potential in 2016. In a worst case, 3 years from the NEO’s EIS would put it at 2018.

In regards to the CFM improvements, although I don’t doubt that there will be future PIPs I can’t see any reason as to why they would be motivated to rush them onto the Max. Instead I see them concentrating on producing PIP’s for the original 1C version as fitted to the NEO and C919 as this is where they face competition and due to the substantial changes required to make the engine work on the 737, I’d say its highly unlikely that these PIPs would be applicable to the 1B.

There is also the time aspect, the GTF is at least a year if not two ahead in development, therefore I wouldn’t expect them to introduce any PIPs until 2019/2020 for the 1C and even later for the 1B which would give the NEO and Pratt a couple of years to make a dent in the Max’s market share.

Quoting Stitch (Reply 33):
So should the PW1100G gain all 4%, that will favor that engine on the A320-200 and (especially) A321-200 on longer missions. Might actually make the A321-200neo a true 757-200 replacement in terms of nominal range.

I agree completely, infact if the recent range increase for the NEO is applicable to both engines, then the A321NEO-GTF might even have legs on the 752.

Quoting Stitch (Reply 33):
But Boeing will surely still sell plenty of 737MAXs for shorter missions and will probably still score some orders with long-distance carriers, as well, since the MAX will load even more fuel than the NG.
Quoting PhxA340 (Reply 35):
I am still a big believer that the NEO is going to be the better plane for long distances and the MAX will have the advantages for short trips.

I’m not so sure if the short range/long range difference is still the case for the Max and NEO, however I am sure that the Max is going to sell in significant numbers and be a financial success for Boeing.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 5:03 pm

Quoting rheinwaldner (Reply 38):
Sorry, Daniel Tseng does not nearly qualify to be in the same league as SUH. SUH knows what he knows because Boeing has told him so as potential customer. And SUH is not biased. His advice should be taken very seriously by Boeing.

That's right, SUH would never hype some numbers (real or imagined) to gain some sort of a benefit for himself. Not his style. Nope. No way..
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 5:05 pm

Quoting rheinwaldner (Reply 30):
And the huge fan is the essential feature of the GTF. In fact the GTF is primarily invented to raise the fansize without getting in troubles with too much speed at the fan tips.

I think you are about half right.

A lot of the reading I'm doing these days on the topic is more about how the fact that the fan spins at its slower optimum speed while the core spins at its faster optimum speed (which is three times faster, and some are suggesting 4x or 5x in the future) is at least as much of a game changer if not more.

It means you need fewer stages in the engine, which gets rid of a lot of heavy, expensive and high maintenance parts, mainly compressor and turbine blades, but also extra spools, bearings, case sections, etc. And as Rolls will tell you, a shorter spool doesn't need to be as rigid as a longer spool and thus it is even lighter, so there are knock-on benefits.

Some complain about the heavy, expensive and maintenance gearing of the GTF, but one important point is you are trading off parts that are lifetime limited such as blades for ones that Pratt says are not lifetime limited, namely the gears. I don't know if Pratt guarantees the gears for life or not, but it'd be interesting to know.

Quoting RickNRoll (Reply 34):
The article is in Aviation News, which is subscription only. We are relying on the blogger making fair quotes from the article, which he has read and we haven't. If the quotes are accurate, then Boeing has a problem.

I think you are making a good point about us relying on the blogger, but I really don't see any news here.

Those who have been following know that the GTF has the strengths pointed out above yet some concerns about the gearing itself and concerns that Pratt is playing it safe in more traditional areas such as materials and core design.

They also know that CFMi is taking a lot of risk in materials, in particular the use of CMCs (cermic matrix composites) in the turbine, and is having to tweak almost everything on the engine to keep up with Pratt.

We also know that it looks like the MAX may have advantages on longer stage lengths whereas NEO may have advantages on shorter stage lengths.

So, no news here.

None of us knows how this particular game will turn out, and we won't till after the MAX ships, which is planned to be a year and a half after NEO ships.
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Daysleeper
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 5:31 pm

Quoting Roseflyer (Reply 39):
What I really call into question is that if this 4% is true, why are the orders for the GTF and LeapX split almost 50-50 on the NEO?

The performance advantage isn’t guaranteed, I understand this to be “Pratt’s comeback” after over promising and under delivering on previous projects they really wanted to get this one right so this time round, they are planning on over delivering.

So with no guaranteed advantage, Pratts history of over-promising and as you mention yourself the possibly of maintenance issues then I wouldn’t expect them to have a lead in the order numbers. In fact, all things considered I believe they are doing well to maintain 50% at this stage.
 
astuteman
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 5:50 pm

Quoting Stitch (Reply 33):
If lightsaber is correct, that 4% likely won't become available until after 2020. CFM won't be standing still themselves during that time


Not sure I get this. The GTF will EIS in 2013. So IF (and I stress if) there is 4% up Pratt's sleeve, it should be pretty much manifest by the EIS of the A320NEO. Of course this is an "if".

Quoting Stitch (Reply 33):
But Boeing will surely still sell plenty of 737MAXs for shorter missions and will probably still score some orders with long-distance carriers, as well, since the MAX will load even more fuel than the NG.

Don't disagree, to be honest. I must admit to be eagerly anticipating the MAX's specs, which I believe should be around by the end of the year, to see what has, or is pledged to be, done.

Quoting travelavnut (Reply 29):
Haha!! Pot, meet Kettle

The most eyebrow raising bit of this whole thread to me is watching the same people get "holier than thou" about this allegedly biased blog who would be all over a blog biased in the other direction like a rash. Circuses couldn't provide better, to be honest.

Quoting neutronstar73 (Reply 37):
Please be gone. You add nothing to the thread, except a targeted name calling.

All references to "direct hits" studiously avoided....  
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 5:50 pm

Quoting rheinwaldner (Reply 38):
Sorry, Daniel Tseng does not nearly qualify to be in the same league as SUH. SUH knows what he knows because Boeing has told him so as potential customer.

Why would Boeing only tell SUH, a potential customer, that the plane is 4 tons over weight and not tell the actual customers the same? None of them, to my knowledge, have released any statements noting such an overage.

Daniel Tseng claims he has spoken with Boeing engineers and those engineers tell him the plane is not that heavy. I give the opinion of Boeing's engineers a bit more weight than I do SUH. *shrug*



Quoting Daysleeper (Reply 40):
In regards to the CFM improvements, although I don’t doubt that there will be future PIPs I can’t see any reason as to why they would be motivated to rush them onto the Max. Instead I see them concentrating on producing PIP’s for the original 1C version as fitted to the NEO and C919 as this is where they face competition and due to the substantial changes required to make the engine work on the 737, I’d say its highly unlikely that these PIPs would be applicable to the 1B.

CFM is going to sell a hell of a lot more engines on the MAX then they will on the C919. I would not be surprised if they sell more engines on the MAX than the neo. CFM would be insane to NOT focus on the LEAP-X1B because that is where they're going to be making the bulk of their money.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 6:33 pm

Quoting Stitch (Reply 45):
CFM is going to sell a hell of a lot more engines on the MAX then they will on the C919. I would not be surprised if they sell more engines on the MAX than the neo. CFM would be insane to NOT focus on the LEAP-X1B because that is where they're going to be making the bulk of their money.

As I said, I don’t doubt that they will indeed develop PIPs I just believe that they won’t materialise until at least 2 or 3 years after the GTF has received its first round of updates. Let’s also not forget that Pratt aren’t going to be staying still either, it’s perfectly possible that they could counter any CFM PIP with one of their own which would maintain the advantage.
 
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 7:15 pm

Quoting astuteman (Reply 44):
Circuses couldn't provide better, to be honest.

Sure, but again, it seems to go both ways. Of course, that's true everywhere. When you listen to political commentary, they will throw someone under the bus every time - unless they say something they agree with. Then it's "Except they are right THIS TIME." lol

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roseflyer
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 7:52 pm

Quoting Daysleeper (Reply 40):
In regards to the CFM improvements, although I don’t doubt that there will be future PIPs I can’t see any reason as to why they would be motivated to rush them onto the Max. Instead I see them concentrating on producing PIP’s for the original 1C version as fitted to the NEO and C919 as this is where they face competition and due to the substantial changes required to make the engine work on the 737, I’d say its highly unlikely that these PIPs would be applicable to the 1B.

That is a logical statement, but another factor is that the 737 is a higher production rate airplane and has more money to fund research and development. Boeing pays for CFM to make Performance Improvements to the airplane. CFM also earns huge amounts of money selling those improvements via retrofit Service Bulletins. The purchases go beyond the initial sales campaign.

Although it may seem true, I don't believe that CFM puts more money into development on the A320 variant of the engine or creates PIPs faster for the A320 variant than the Boeing variant. I don't see them doing that when looking at the CFM56 vs V2500 competition.
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Daysleeper
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RE: Doubts About The Engine Of The MAX

Thu Apr 12, 2012 8:12 pm

Quoting Roseflyer (Reply 48):
Although it may seem true, I don't believe that CFM puts more money into development on the A320 variant of the engine or creates PIPs faster for the A320 variant than the Boeing variant. I don't see them doing that when looking at the CFM56 vs V2500 competition.

That’s not what I said, my point was that they have more to gain by improving the 1C as there is a competitor, where as they are going to sell the 1B regardless. And again, that’s not to say that they won’t develop PIPs for it, I just think given the added complexity and its later EIS they won’t be available until at least 2 years after the GTF has received its initial update thus giving Pratt and Airbus yet more time to eat into the Max’s market share.