LeapX Engine Performance On Track For 737 & A320

roseflyer · Sun May 24, 2015 2:18 pm

It looks like the LEAP X is on track to do as planned regarding schedule, fuel efficiency and weight. There have been debates about whether early on performance short falls are going to be overcome. It appears that they will attain the promised performance levels at entry in to service.

Here is a quote

"I am completely confident of attaining the promised performance levels when the Leap enters service" as planned next year, said Safran chief executive Jean-Paul Herteman recently.

For the 737 MAX

The LEAP-1B for the B737 MAX made its first test flight in California on May 7 on a modified Boeing 747.

"With this major engine milestone and the test results to date, we continue to be confident that the LEAP-1B-powered 737 MAX will provide our customers with the most fuel efficient, reliable and maintainable airplane in the single-aisle market," the head of the 737 MAX programme at Boeing, Keith Leverkuhn, said in a statement.

CFM said the LEAP-1B "is on track to deliver 14 percent more fuel efficiency" compared with current 737 planes, in line with targets.

http://finance.yahoo.com/news/boeing...8DZ3ExBHBvcwMzBHZ0aWQDBHNlYwNzcg--

For the A320 NEO

Meanwhile, the first A320neo equipped with LEAP-1A engines made its maiden flight in Toulouse, France, on Tuesday.

"Today marks yet another important step forward in the development of the A320neo and I would like to warmly thank all the teams who made this first flight happen," said Klaus Roewe, head of the A320 programme at Airbus.

http://news.yahoo.com/next-generatio...ap-towards-delivery-073745004.html

[Edited 2015-05-24 08:05:54]

[Edited 2015-05-24 08:06:55]

PlanesNTrains · Sun May 24, 2015 4:37 pm

Call me jaded, but comments like:

Quoting Roseflyer (Thread starter):
I am completely confident

and

Quoting Roseflyer (Thread starter):
we continue to be confident that

and

Quoting Roseflyer (Thread starter):
is on track to deliver

no longer instill confidence in me.

Hopefully it all comes together as planned.

-Dave

SEPilot · Sun May 24, 2015 4:52 pm

With the stakes involved, and all the bad publicity that Boeing received over the 787 fiasco, I would not think that prominent figures like Herteman would make statements like that without being pretty sure that they were true. However, I have to share some of PlanesNTrains skepticism. I certainly hope that the statements are true.

speedbored · Sun May 24, 2015 5:09 pm

Quoting SEPilot (Reply 2):
However, I have to share some of PlanesNTrains skepticism

Me too.

Though I think a more telling part of the quote from Safran is:
"attaining the promised performance levels when the Leap enters service"
Personally, I think this suggests that they are likely to EIS a little below spec but above the performance guarantees. The "attaining" definitely seems to confirm that they are currently below guaranteed performance.

It is also interesting that the quote from Boeing:
"the LEAP-1B-powered 737 MAX will provide our customers with the most fuel efficient, reliable and maintainable airplane in the single-aisle market"
doesn't specify a timeframe for that to happen.

StTim · Sun May 24, 2015 5:09 pm

As has been stated here - Guarantees and Publicity statements re fuel burn etc are two very different things.

I do not read on target to meet guarantees not as on target to beat GTF by 4% - which I think was one of the marketing statements.

[Edited 2015-05-24 10:55:20]

tommy1808 · Sun May 24, 2015 5:45 pm

Quoting SEPilot (Reply 2):
I certainly hope that the statements are true.

but what is truth? Isn't it the most optimistic why of putting something the legal department thinks is vague enough to protect from being sued by shareholders if it doesn't pan out?

Best regards
Thomas

JoeCanuck · Mon May 25, 2015 1:16 am

Quoting tommy1808 (Reply 5):

Nobody will know the real truth until an airline leaks the numbers to the public.

lightsaber · Mon May 25, 2015 3:23 am

Too many "wiggle words.". I'm a Pratt fan, so I do not claim to be unbiased... But I'm reading a miss with a later PIP.

Put another way GE was equally confident on the 787 and should soon hit promise (a tougher standard than guarantee).

Lightsaber

Boeing778X · Mon May 25, 2015 3:32 am

Last I checked, EIS of the 737 MAX 8 is maintained at Q3 2017.

I would imagine the first MAX frame will roll out within the next 12 to 16 months.

bgm · Mon May 25, 2015 3:32 am

Their optimism smells 787-esque, circa 2007.....

ODwyerPW · Mon May 25, 2015 4:14 am

I prefer to celebrate that engine makers are making steady progress, even if they were a bit overly optimistic in the beginning about the extent of their progress.

While I agree the language could be interpreted as "will achieve spec, following a PIP", I'm still pleased progress is being made.

No doubt lawyers working in behalf of the airlines will make sure the airlines receive compensation should the engines miss guarantees.

Big one for me will be 'reliability'... hot section on the LEAP... gearboxes on the GTF (not to turn this into a GTF discussion).

Peter

JoeCanuck · Mon May 25, 2015 6:22 am

When the Airinsight article came out, people complained that CFM and Boeing weren't commenting...and that must mean that the LEAP was crap.

Now that CFM and Boeing have spoken up and shown about as much confidence in public as possible that their engine will be all that, they must really mean that the LEAP is crap, since they haven't supported it in just the right way.

Oy vey.

rheinwaldner · Mon May 25, 2015 7:58 am

There are still reputeable bloggers who doubt the presented PR...
http://aeroturbopower.blogspot.ch/20...05/the-cfm-leap-1b-discussion.html

Quote:
This kind of testing is new to me, I never heard that these kind of tests were done. In the end it is very expensive to build a test engine solely to measure the performance with so called “end of life ”clearances”.

(this as a response because CFM said the shortfall came from a test with with a deliberatly degraded engine).

seahawk · Mon May 25, 2015 8:39 am

Makes sense. They would have to guess how the engine will age, as only real running will show how it will age. Building an engine to a used specification at that stage of the program makes little sense to me.

SeJoWa · Mon May 25, 2015 9:09 am

I know next to nothing about tip clearances and seals, but this is an engine that's on track to be built at a rate of very roughly 150 per month. Exclamation mark. And expected to be left on wing for a long time, judging by the current item.

It makes a lot of sense to me, given the inclusion of so much new technology, to actually measure how the assembled engine degrades over time, and one can assume there are data sets specific to every relevant new element that provide a useable baseline individually.

Rheinbote · Mon May 25, 2015 9:17 am

The question is what CFM could do about a shortfall in case? I'd assume that the LEAP already incorporates whatever is in CFM's portfolio of technology bricks in order to counter the PurePower family and make good on the latter's benefit from geared fan technology.

seahawk · Mon May 25, 2015 9:34 am

Quoting SeJoWa (Reply 14):
It makes a lot of sense to me, given the inclusion of so much new technology, to actually measure how the assembled engine degrades over time, and one can assume there are data sets specific to every relevant new element that provide a useable baseline individually.

That would make sense, but they say the did built a new engine to simulate a used standard. So obviously all parts would need to be artificially aged. That would be based on your simulations and would at best confirm that the fuel consumption of an old engine would be the same as your simulation says, but only if your simulation on how each part ages is correct. The interesting test would be to see if the parts age as expected.

SeJoWa · Mon May 25, 2015 10:35 am

Quoting seahawk (Reply 16):
The interesting test would be to see if the parts age as expected.

Absolutely, but as I've written, they must have a good enough idea about the ageing of individual parts. What's certainly harder to predict are cumulative effects. An aged engine could, at a certain point, display some discontinuity leading to more severe deterioration? If some parts aren't cooled adequately, this engine's high temps would make it especially susceptible.

EPA001 · Mon May 25, 2015 12:20 pm

Quoting SEPilot (Reply 2):
I have to share some of PlanesNTrains skepticism.

Me too, but the proof of the pudding is in the eating. So maybe in the end they will get it right although I do expect them never to beat the GTF which is the better concept to me and has (much) more potential for improvement.

Quoting JoeCanuck (Reply 6):
Nobody will know the real truth until an airline leaks the numbers to the public.

That is true, but sooner or later that will happen.

rcair1 · Mon May 25, 2015 12:47 pm

Quoting JoeCanuck (Reply 11):
Oy vey.

Quoting rheinwaldner (Reply 12):
his kind of testing is new to me, I never heard that these kind of tests were done. In the end it is very expensive to build a test engine solely to measure the performance with so called “end of life ”clearances”.

I've done it. Not on jet engines, but on mechanical devices that wear - to make sure the tolerance stacks worked with the specifications. It is very likely that the tolerances in the engine are tight and they want to make sure they hold.

Quoting seahawk (Reply 16):
hat would make sense, but they say the did built a new engine to simulate a used standard. So obviously all parts would need to be artificially aged

Just like the brakes used in RTO testing for certification.

seahawk · Mon May 25, 2015 1:09 pm

Quoting SeJoWa (Reply 17):
Absolutely, but as I've written, they must have a good enough idea about the ageing of individual parts. What's certainly harder to predict are cumulative effects. An aged engine could, at a certain point, display some discontinuity leading to more severe deterioration? If some parts aren't cooled adequately, this engine's high temps would make it especially susceptible.

Yes, but for me it feels a bit early for such test.

roseflyer · Mon May 25, 2015 1:49 pm

Quoting rheinwaldner (Reply 12):
There are still reputeable bloggers who doubt the presented PR...
http://aeroturbopower.blogspot.ch/20...05/the-cfm-leap-1b-discussion.html

Quote:
This kind of testing is new to me, I never heard that these kind of tests were done. In the end it is very expensive to build a test engine solely to measure the performance with so called “end of life ”clearances”.

(this as a response because CFM said the shortfall came from a test with with a deliberatly degraded engine).

As an engineer with significant experience in the industry, I can personally tell you that I find the blog that you quote is not from a reputable or knowledgeable blogger. I don't know why the blogger came to the conclusion that there is a design problem or performance shortfall because they are doing a qualification test that he does not know much about.

That article indicates that the blog is from an enthusiast, but not from someone who knows more about the performance of the airplane than the Boeing and Saffran executive.

Quoting Rheinbote (Reply 15):
The question is what CFM could do about a shortfall in case? I'd assume that the LEAP already incorporates whatever is in CFM's portfolio of technology bricks in order to counter the PurePower family and make good on the latter's benefit from geared fan technology.

If there is some type of shortfall, then something in the design is not performs in as intended. This is the purpose of qualification testing. They will find out what is not working as designed and fix it.

My first engineering mentor/lead told me when I just graduated college and started working that if you pass every single qualification test on your first try, that means as a designer you failed because you left too much safety margin in your design (ie design is too heavy or the goals weren't good enough). If they aren't below their goals at this point in testing, we would expect that they didnt set high enough goals in the beginning. While exceeding objectives are good, it is better to set higher goals and meet them than predict poor results and exceed.

Stitch · Mon May 25, 2015 3:08 pm

Quoting seahawk (Reply 20):
Yes, but for me it feels a bit early for such test.

CFM has stated LEAP-X will maintain the same (low) maintenance costs as the CFM56 family, so if CFM is making maintenance and part-life guarantees as part of their current LEAP sales contracts, I could see them wanting to have an idea of how those parts are holding up so they don't end up with a situation like Pratt on the early PW4090s where the guide swirlers had a service life only 33% of plan or GE on the early GE90 where the fuel-injectors were failing within two dozen flights.

roseflyer · Mon May 25, 2015 8:49 pm

Quoting Stitch (Reply 22):

Quoting seahawk (Reply 20):
Yes, but for me it feels a bit early for such test.

CFM has stated LEAP-X will maintain the same (low) maintenance costs as the CFM56 family, so if CFM is making maintenance and part-life guarantees as part of their current LEAP sales contracts, I could see them wanting to have an idea of how those parts are holding up so they don't end up with a situation like Pratt on the early PW4090s where the guide swirlers had a service life only 33% of plan or GE on the early GE90 where the fuel-injectors were failing within two dozen flights.

As far as I have heard, the CFM56 has the longest life between engine removals of any modern jet engine. I have heard of engines lasting 40,000 hours on wing. To get those extremely high mtbur numbers, extensive testing is required. The fact that they are doing extensive certification and qualification testing does not imply there are any deficiencies in the engine. I have not heard of problems found during testing so far. Maybe someone has those details.

lightsaber · Tue May 26, 2015 12:23 am

Quoting seahawk (Reply 16):
That would make sense, but they say the did built a new engine to simulate a used standard. So obviously all parts would need to be artificially aged. That would be based on your simulations and would at best confirm that the fuel consumption of an old engine would be the same as your simulation says, but only if your simulation on how each part ages is correct. The interesting test would be to see if the parts age as expected.

Sorry to nitpick, but one of the major issues with the 'used at tolerance' is the temperatures within the engine. While fuel burn will be interesting, how an engine ages for fuel burn is less important at this stage. It is safety so that if bore-o-scope checks will find certain gaps. If the engine is within the test engine gaps, the engine may continue running. So if the engine if found to operate OK, in service engine may continue to run. This is a required step in engine certification; while it can be skipped with earlier overhauls of in service engines, this is the lower cost option if a significant number of engines is expected to be sold quickly (as with the LEAPx).

Lightsaber

rheinwaldner · Tue May 26, 2015 4:17 am

Quoting seahawk (Reply 13):
Makes sense. They would have to guess how the engine will age, as only real running will show how it will age. Building an engine to a used specification at that stage of the program makes little sense to me.

If it was exactly as described (testing end-of-life clearances), I could imagine the following:
- The new design is critical in certain areas which cause quicker wear
- The wear causes certain physical dimensions to become worse (e.g. clearance between turbine and casing)
- Other than letting an engine run a whole lifetime, you can only simulate the physical dimensions of an end-of-life engine for test purposes
- So the expected wear is "unusual" enough to extra built an end-of-life simulation engine "unusually" early.
- The found impact on fuel burn seems to confirm that they have not been haunting ghosts only....

Quoting rcair1 (Reply 19):
I've done it. Not on jet engines, but on mechanical devices that wear - to make sure the tolerance stacks worked with the specifications.

It is not about whether they would do those test or not. It is about the motivation why those tests are done so early.

Quoting Roseflyer (Reply 21):
if you pass every single qualification test on your first try, that means as a designer you failed because you left too much safety margin in your design (ie design is too heavy or the goals weren't good enough).

The goals in this case are primarily given by the competition. CFM obviously is planning to deliver specs which satisfy a large chunk of the market. So the goals have been set sufficiently high. But this does not mean that you need to haunt the goals up to EIS and beyond. You can reach the goals early, continue to improve the product and deliver even better engines at EIS (as Pratt seems to be doing).

Quoting Stitch (Reply 22):
I could see them wanting to have an idea of how those parts are holding up so they don't end up with a situation like Pratt on the early PW4090s where the guide swirlers had a service life only 33% of plan or GE on the early GE90 where the fuel-injectors were failing within two dozen flights.

But as I understood those tests have exactly not been endurance tests.

seahawk · Tue May 26, 2015 6:10 am

Quoting lightsaber (Reply 24):
Sorry to nitpick, but one of the major issues with the 'used at tolerance' is the temperatures within the engine. While fuel burn will be interesting, how an engine ages for fuel burn is less important at this stage. It is safety so that if bore-o-scope checks will find certain gaps. If the engine is within the test engine gaps, the engine may continue running. So if the engine if found to operate OK, in service engine may continue to run. This is a required step in engine certification; while it can be skipped with earlier overhauls of in service engines, this is the lower cost option if a significant number of engines is expected to be sold quickly (as with the LEAPx).

Lightsaber

Maybe they took parts with high hours out of component testing and made an engine from those. Otherwise tolerance testing could be done with component testing only, if you want to prove that the engine will run safely. Granted, you can be right as they are very much focusing on reliability and time on the wing to promote the lEAP over the GTF.

Another thing with imho is ignored is, that the original rumour said that the LEAP1B was doing worse than the LEAP1A. We have however only heard that the 4-5% off were measured with a LEAP1 used for tolerance testing. Considering the certification timeline and the fact that they plan for 28 ground test engines for the whole LEAP line, I think it would be bit strange, if it would be a LEAP1B, unless they have reasons to do such a test on the 1B so early.

[Edited 2015-05-25 23:25:53]

[Edited 2015-05-25 23:26:35]

Revelation · Tue May 26, 2015 11:40 am

Quoting Roseflyer (Reply 21):
While exceeding objectives are good, it is better to set higher goals and meet them than predict poor results and exceed.

That's fine if you have some sort of plausible plan to reach the higher goal. Too often I see executives just moving the goal line with absolutely no way of knowing if it can be achieved even with infinite budgets. Many times in my business (not aviation) we end up with incredibly fragile and constrained solutions so we can claim "success" that only happens under very ideal circumstances rarely achieved in the real world.

Quoting rheinwaldner (Reply 25):
It is not about whether they would do those test or not. It is about the motivation why those tests are done so early.

And to me it was a convenient way to deflect away any discussion of their current understanding of the current performance of the engine. Of course it's their right to keep that information to themselves, but they've made some claims that are quite aggressive so they will continue to be asked.

roseflyer · Tue May 26, 2015 6:36 pm

Quoting rheinwaldner (Reply 25):

Quoting Roseflyer (Reply 21):
if you pass every single qualification test on your first try, that means as a designer you failed because you left too much safety margin in your design (ie design is too heavy or the goals weren't good enough).

The goals in this case are primarily given by the competition. CFM obviously is planning to deliver specs which satisfy a large chunk of the market. So the goals have been set sufficiently high. But this does not mean that you need to haunt the goals up to EIS and beyond. You can reach the goals early, continue to improve the product and deliver even better engines at EIS (as Pratt seems to be doing).

Airplanes are sold on life cycle costs. If the airplane is more efficient, it attracts a higher purchase price. Less efficient airplanes get lower prices. The performance numbers usually represent the most realistic numbers based on analysis. Based in the potential error and accuracy of predictions, promised performance is backed off depending in the confidence of those predictions. If CFM is too cautious on their numbers, they lose millions in potential revenue. Reaching the goals early and then exceeding them is great, but it also means that they lost significant revenue and potential orders. If they aren't cautious enough to account for risks in the design and modeling, then they also lose millions in penalties. The fuel efficiency numbers aren't based primarily on the competition, it is based on what CFM actually thinks they can do and how accurately they can measure it.

When the CEO says that he is confident in obtaining the promised numbers, that should be taken as a good sign.

Revelation · Wed May 27, 2015 1:12 am

Quoting Roseflyer (Reply 28):
Based in the potential error and accuracy of predictions, promised performance is backed off depending in the confidence of those predictions. If CFM is too cautious on their numbers, they lose millions in potential revenue. Reaching the goals early and then exceeding them is great, but it also means that they lost significant revenue and potential orders.

To me this brings to mind how GE90-77 had its issues initially (mostly maintenance rather than performance, IIRC) so must have cost GE a lot to satisfy contracts. One would then presume that they were initially pretty conservative on the GE90-115 contracts but surely made it up on the later contracts.

It also highlights how marketing cooks up a number and throws it out to the public, yet we never really know what was written to any of the contracts. It means we cook up different words like "promise" versus "guarantee" which are actually for the same quantity, fuel burn. This is why I never went into marketing!

astuteman · Wed May 27, 2015 5:24 am

Quoting Roseflyer (Reply 21):
if you pass every single qualification test on your first try, that means as a designer you failed because you left too much safety margin in your design (ie design is too heavy or the goals weren't good enough).

Whatever happened to "under-promise and over-deliver" at Boeing?
I've been an engineer for a long time too, and I don't subscribe to that theory one bit.
Particularly when the technology boundary is being pushed the way it is on these new engines.
It runs the risk of a whole slew of continual design revisions approaching, and post, EIS.
That's horrible from a config management viewpoint, and a disaster from a cost viewpoint.
There should always be some margin in hand to the specified goals - the size of this being dependent upon the extent of the technology risk being applied.
Anything else is frankly bad engineering

Quoting rheinwaldner (Reply 25):
You can reach the goals early, continue to improve the product and deliver even better engines at EIS (as Pratt seems to be doing).

Under-promise and over-deliver? It could catch on

Rgds

JoeCanuck · Wed May 27, 2015 8:49 pm

What we have so far, are people not directly connected to, or willing to go public with alleged concerns...so basically rumors.

I have no idea what it's true and what is not...nobody outside of the program does.

What this does mean is that it is much too early to make definitive statements concerning the engines. Maybe they are under promising and over performing....and maybe the opposite is true.

What we do have is, the folks dealing with the situation saying everything is A OK.

What we haven't heard is anything from the many airlines which would be the ones dealing with any shortfall...and surely they must be in the loop at this point.

They were among the loudest complaining about 787 problems and I can't imagine they would be shy about dissing the LEAP if the situation was as severe as some bloggers are predicting...but zip so far, not a peep.

Those are the guys whose statements I would take seriously.

lightsaber · Wed May 27, 2015 8:49 pm

The GEnX made similar promises. Alas GE has lost their reputation. Now my last information was in March, but I'm not expecting the LEAP-1A to meet promise. I hope I'm wrong and CFM is competitive and a close horse race.

Quoting seahawk (Reply 26):
of

You make good points, but a full engine test is proof to allow long overhaul intervals. Component testing is good but if temperatures or pressures are on the money. A full engine test exonerates analysis off by a bit. Expensive, but it ensures engines that meet boroscope can keep flying.

Lightsaber

KELPkid · Wed May 27, 2015 8:53 pm

Quoting lightsaber (Reply 32):
The GEnX made similar promises. Alas GE has lost their reputation. Now my last information was in March, but I'm not expecting the LEAP-1A to meet promise. I hope I'm wrong and CFM is competitive and a close horse race.

Probably not nearly as bad as Pratt did after the P&W6000 fiasco...

It is good to see Pratt and Whitney back in the good graces of Airbus, though!

lightsaber · Thu May 28, 2015 11:15 am

Quoting KELPkid (Reply 33):
Probably not nearly as bad as Pratt did after the P&W6000 fiasco...

Pratt missed on the PW2000, PW4000 (initial), PW4098 (4% miss on the upgrade), and PW6000. There is a reason they were basically kicked out of the business. But for a while, GE was known to always beat promise. That ended with the GEnX.

Lightsaber

Richard28 · Thu May 28, 2015 12:41 pm

Quoting JoeCanuck (Reply 31):
What we haven't heard is anything from the many airlines which would be the ones dealing with any shortfall...and surely they must be in the loop at this point.

They were among the loudest complaining about 787 problems and I can't imagine they would be shy about dissing the LEAP if the situation was as severe as some bloggers are predicting...but zip so far, not a peep.

It could also be that airlines have performance guarantees written into their contracts, so they will get a contractual perforance either through the LEAP engine itselft or through compensationary payments.

There may also be confidentiality agreements in place which ccould explain the silence.

I guess we will never know for sure this far in advance, however perhaps loking at the split of future orders on the A32Xneo between PW and LEAP may give us an indication, or possibly the split between the MAX and neo, however with limited availiability and discounting this may not be as easy to spot.

r2rho · Thu May 28, 2015 4:29 pm

Just a little reminder, since there is only talk about GE, that CFM is a GE + Snecma joint venture at 50% each. There is no majority shareholder. So if there is a miss it is as much a GE issue as a Snecma one.

Quoting Richard28 (Reply 35):
It could also be that airlines have performance guarantees written into their contracts, so they will get a contractual perforance either through the LEAP engine itselft or through compensationary payments.

This OTOH is where the GE side of the JV does come into play, as through GECAS they offer lease deals, financing, etc. So it could very well be, particularly for GECAS customers, that there are contractual guarantees built in, and if there is a miss, it will be compensated through lease rates, etc.

mffoda · Thu May 28, 2015 5:38 pm

Here's a neo update form Airbus programmes chief Didier Evrard regarding the engines. (From FG article)

"Evrard says that he is confident that both powerplant types will reach the fuel-burn levels promised by their manufacturers, pointing out that the airframer has yet to conduct detailed analysis on the Leap-1A performance because it "hasn't had enough experience in flight".

He adds that Airbus and P&W are addressing a "maturity issue" on the PW1100G, relating to a seal in the vicinity of the high-pressure compressor, some production batches of which have shown "slightly more deviations" during operation.

Flight testing is "on hold" until the issue is resolved, he says, but he expects this to be overcome within a few days."

http://www.flightglobal.com/news/art...ign-making-steady-progress-412838/

neutronstar73 · Thu May 28, 2015 11:03 pm

Oh boy....we are at this again....

Last time we had this thread, many people relied on information from a website they normally dismiss as being "fanboyish", and used that information to proclaim doom for CFM, and more pointedly, GE, because they wanted them to fall from their place as the aircraft engine leader. Mind you, GE and CFM got there because they are good and don't make bad products.

Then we had a whole bunch of people proclaiming that it was "a guarantee" that P&W would "beat promises" and CFM would surely "not meet specifications". Even though recent history of both painted an opposite view (GENx aside, but that was pushing it...RR didn't meet specs either but somehow didn't get flamebroiled over it like GE).

No CFM comes out and says the report that many people relied upon was from a test rig, and that all the naysayers were wrong (as usual).

And here we are...people doing the same thing, and CFM is guaranteeing performance. I think I will listen to them, because they have a lot to lose, especially reputation, if they don't perform. They certainly wouldn't be putting themselves out there if they didn't think they could make it. PW "HAS" to be good and deliver or they might as well close up the commercial airliner side and concentrate on military business and light aircraft. They've had too many "misses" to have another one.

lightsaber · Fri May 29, 2015 3:33 am

Quoting mffoda (Reply 37):
He adds that Airbus and P&W are addressing a "maturity issue" on the PW1100G, relating to a seal in the vicinity of the high-pressure compressor, some production batches of which have shown "slightly more deviations" during operation.

I wish I could claim surprise and doubt. This will have to be addressed. I'm happy it seems to be a quick issue.

Quoting mffoda (Reply 37):
"Evrard says that he is confident that both powerplant types will reach the fuel-burn levels promised by their manufacturers, pointing out that the airframer has yet to conduct detailed analysis on the Leap-1A performance because it "hasn't had enough experience in flight".

Airbus knows by the 3rd flight the rough fuel burn of the engine. It is in their corporate culture; it is just something they do. I'm only aware of one other airframer who meters the fuel in their prototypes more intensely and compares to expectations. With numerous flights with the PW1100G, Airbus could tell relative fuel burn within 1% by now. Something doesn't 'smell right' about that Airbus statement.

Lightsaber

seahawk · Fri May 29, 2015 5:17 am

Quoting mffoda (Reply 37):
"Evrard says that he is confident that both powerplant types will reach the fuel-burn levels promised by their manufacturers, pointing out that the airframer has yet to conduct detailed analysis on the Leap-1A performance because it "hasn't had enough experience in flight".

There is the "confident" again. Considering that they are surely knowing the fuel burn right now, this makes only sense if they know that the current LEAP-1A is not hitting the specs.

rheinwaldner · Fri May 29, 2015 6:54 am

Quoting JoeCanuck (Reply 31):
What we do have is, the folks dealing with the situation saying everything is A OK.

Reminds me on the 787 about a month before the initial date for first flight.

Quoting neutronstar73 (Reply 38):
No CFM comes out and says the report that many people relied upon was from a test rig, and that all the naysayers were wrong (as usual).

In which recent project were the naysayers wrong?
- The 787? No
- The 748? No
- The 787&748 engines? No

Only for the A350 and the A350 engine we can say that the naysayers were wrong.

roseflyer · Fri May 29, 2015 11:48 am

Quoting rheinwaldner (Reply 41):

In which recent project were the naysayers wrong?
- The 787? No
- The 748? No
- The 787&748 engines? No

Only for the A350 and the A350 engine we can say that the naysayers were wrong.

Please don't make this Airbus vs Boeing. Both the A320 neo and 737max use the LeapX so this is should be and Airbus and Boeing discussion. The LeapX is more popular on the A320 that the PW engine, so we know at least the airlines feel that it is a competitive engine based in their analysis.

parapente · Fri May 29, 2015 12:17 pm

When Cfm (GE) 'launched' their engine it was effectively a knee jerk response to the P&W GTF. The GTF was going onto the A320 (as much as Boeing tried to persuade Airbus not to go down this particular road).
The GTF promised 'X'. Cfm had to promise the same (or very similar) otherwise there would have been no point.They had to anyway or else Boeing were a dead duck in the narrow-bodied sector and that was not going to happen.
The 'bet' was you could achieve the same efficiency as GTF technology if you raised the core temps and pressures high enough but stayed 'conventional'- direct drive.
If this turns out to be true then (in effect) P&W have been wasting their time and billions$$ on their (much more) complex geared fan approach. Personally I think this was always highly unlikely since P&W engineers are not that stupid.Hell even RR can see that the future has to be geared (and they know tons about 'hot' cores).
I imagine the GE 'bet ' was to be 'good enough'. Perhaps P&W have just raised the stakes again. But right now their engines are stuck on the ground......so no plane sailing even for them.
In the end it is more than likely that GE will produce an engine that is 'good enough'- good enough to met their legal commitments - but probably not a drop more. Boeing have got the sales in on the the MAX. If/when the cat comes out of the bag that a GTF engines is 'naturally' a better and more efficient technology, then you will see the 737 replacement come out awful quickly.Oh and yes it will be able to carry a GTF style engine!

par13del · Fri May 29, 2015 12:33 pm

Quoting astuteman (Reply 30):
Whatever happened to "under-promise and over-deliver" at Boeing?

I thought this was about the engines not Boeing.

Quoting parapente (Reply 43):
The GTF was going onto the A320 (as much as Boeing tried to persuade Airbus not to go down this particular road).

Really, someone at Boeing actually thought that Airbus would listen to them and not select their own engine?
I need to do more research on the GTF versus LEAP debate.

Quoting parapente (Reply 43):
Cfm had to promise the same (or very similar) otherwise there would have been no point.They had to anyway or else Boeing were a dead duck in the narrow-bodied sector and that was not going to happen.

Well if the engine was not as good how was Boeing going to prevent it from happening?

Quoting parapente (Reply 43):
Boeing have got the sales in on the the MAX. If/when the cat comes out of the bag that a GTF engines is 'naturally' a better and more efficient technology, then you will see the 737 replacement come out awful quickly.Oh and yes it will be able to carry a GTF style engine!

So Pratt will suddenly become Boeing's best friend and GE will be relegated to the scrap heap or do we believe that GE is also working on a geared approach and they are just buying time with a good enough engine?

If the straits are so dire one has to wonder why Boeing did not stick to its original plans and do the NSA versus being forced to do the MAX, or even better, if it is all about the engines just spend the extra to raise the a/c off the ground.
Spending billions on the MAX only to see it rendered obsolete in a couple years requiring additional billions to now produce the NSA could put the company out of business.
Perhaps they will be looking for additional government support?

mjoelnir · Fri May 29, 2015 12:42 pm

Quoting Roseflyer (Reply 42):
Please don't make this Airbus vs Boeing. Both the A320 neo and 737max use the LeapX so this is should be and Airbus and Boeing discussion. The LeapX is more popular on the A320 that the PW engine, so we know at least the airlines feel that it is a competitive engine based in their analysis.

It is a Airbus versus Boeing thing. The LEAP lives up to the promises no problem for anybody. The LEAP not living up to the promises is bad for Boeing. Airbus customers can move to the P&W.

astuteman · Fri May 29, 2015 1:15 pm

Quoting par13del (Reply 44):
I thought this was about the engines not Boeing.

It was if you followed the discussion. If you don't like it, suggest deletion. Otherwise ....

Rgds

mffoda · Fri May 29, 2015 1:30 pm

in FG today regarding CFM fuel burn...

"Amid industry speculation that the -1B engine is behind on fuel-burn targets, Boeing's senior vice-president for global sales and marketing John Wojick tells Flightglobal that CFM "is absolutely tracking to their plan" on the Leap-1B, which exclusively powers the 737 Max.

"We're confident that they're going to be very, very successful in meeting the commitments they made to us, and obviously we'll be able to meet our commitments to our customers on the fuel-burn improvement," he says.

"In fact, we're hopeful we'll be able to exceed them," adds Wojick.

The Leap-1B features ceramic matrix composite materials in the stage 2 turbine shroud and a fuel nozzle disc produced using additive layer manufacturing. It is expected to deliver a 14% fuel-efficiency improvement over the CFM56-powered 737NG.

"Results to date are right in line with what we predicted and where we wanted this engine to be," says Allen Paxson, executive vice-president, CFM International."

http://www.flightglobal.com/news/art...7-max-performance-promises-412883/

seahawk · Fri May 29, 2015 2:02 pm

"Results to date are right in line with what we predicted and where we wanted this engine to be," says Allen Paxson, executive vice-president, CFM International."

That is clear, finally.

scbriml · Fri May 29, 2015 2:23 pm

Quoting Roseflyer (Reply 42):
The LeapX is more popular on the A320 that the PW engine, so we know at least the airlines feel that it is a competitive engine based in their analysis.

Per Flood's excellent site:
http://www.pdxlight.com/neomax.htm

CFM currently enjoys a 55/45% advantage on neo.

BUT, there is a significant number of sales where an engine selection has yet to be announced. In fact, so many*, that if they all selected PW (yes, very unlikely, but for illustrative purposes only), then PW would have a 68/32% advantage.

So there is still an awful lot to play for on neo engines.

*There are actually more sales where an engine selection has yet to be made, than sales where CFM has been selected - 1,202 CFM, 998 PW and 1,596 not selected.

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