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EMBSPBR
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Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 3:11 pm

Source: https://www.aviationpros.com/engines-co ... 0-aircraft

Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Pratt & Whitney recently celebrated the 1,000th aircraft powered by GTF engines, delivered to Sichuan Airlines Co., Ltd.
GTF engines power three aircraft families in service today: Airbus A320neo, Airbus A220 and Embraer E-Jets E2.


Excerpt:
"Since entering service in early 2016, the GTF engine family has delivered on its promised ability to reduce fuel burn and carbon emissions
by up to 20 percent, and to dramatically reduce regulated emissions and noise footprint.
With the GTF’s long runway for future growth, Pratt & Whitney is just getting started."

The question that still intrigues me is regarding the durability of its components and costs with PIPs ...

Nice PW promotional video:
https://www.youtube.com/watch?v=EMTXpXrgeiE
 
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Faro
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 4:21 pm

I would love to know the GTF vs LEAP engine figures on the A320neo family…


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lightsaber
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 4:48 pm

EMBSPBR wrote:
The question that still intrigues me is regarding the durability of its components and costs with PIPs ...



"Pratt & Whitney announced that GTF engines powering the A320neo family have achieved a world-class engine dispatch reliability rate of 99.98%. "

...

“Thanks to upgrades completed in close coordination with our customers in 2020, GTF engines for the A320neo family are now delivering industry-leading reliability,”


In other words, incredible reliability on the A320NEO. It went from bad to incredible.

Source:
https://50skyshades.com/news/manufactur ... -Jets%20E2.

PW1500G at 99.88% dispatch reliability, which is amazing!!!
https://airinsight.com/happy-birthday-g ... ay-part-2/
From that link:
Now the bad:"Lufthansa, too, has had its share of issues that had a negative impact on operations. It suffered in-flight shutdowns, low-pressure turbine, and high-pressure compressor issues that requested inspections or engine removals, especially in the first two to three years. “The initial major problems have now been largely resolved and performance, e.g. in terms of fuel consumption, is fine. We are currently working with the manufacturers to extend the service intervals, i.e. the time between two engine overhauls.”"

LEAP and PW1100G have the same dispatch reliability, so no advantage for Pratt, but since that link notes the same on the MAX, this highlights how incredible predictive maintenance is!

This will help new generation aircraft sales and resale values, it will depress prior generation engine values (lower dispatch reliability is a cost as well as fuel burn). In my opinion, prior generation engines without predictive maintenance just cannot be that reliable. For many fleets, this means the cost of backup aircraft is no longer worth it for the latest generation narrowbody aircraft.

Then again, the CFM-56 now has 99.9+% dispatch reliability (I missed it had improved that much):
https://www.safran-group.com/file/downl ... market.pdf

We might be entering an era where the use of backup aircraft fades away. In particular later A320CEO with predictive maintenance.
https://www.safran-group.com/file/downl ... market.pdf

https://www.airbus.com/newsroom/press-r ... opter.html

You have to delve through an Allegiant conference call, but they will brag how the health monitoring is cutting maintenance costs verbally. Take it as my opinion as it always seems to be in calls without a transcript. But they were the launch customer for Skywise predictive maintenance (see prior Airbus link). This is an advantage if fly by wire and I worked on A320 NEO subsystems that had predictive maintenance sensors added and the system used sensors, such as valve position sensors in the predictive maintenance algorithm. e.g., if a valve is more open at cruise, it indicates system wear and replace certain components early if a valve must be open x% to maintain cruise temperature. Or even rebuild a turbine (expensive engine overhaul).

The GTFs have amazing fuel burn. I believe they will now sell better. I believe every airline opperating high utilization aircraft will transition to predictive maintenance aircraft and engines: A320CEO/NEO, A220, E2, and would have been MRJ. Plus some newer widebodies (787 and everything launched after that).

Also consider how the GTF range helps enable more missions. :hyper:

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 4:49 pm

Faro wrote:
I would love to know the GTF vs LEAP engine figures on the A320neo family…


Faro


As of today 919 A320neo family frames delivered (flown out) with LEAP and 711 with GTF.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 5:16 pm

mjoelnir wrote:
Faro wrote:
I would love to know the GTF vs LEAP engine figures on the A320neo family…


Faro


As of today 919 A320neo family frames delivered (flown out) with LEAP and 711 with GTF.

The early PW1100G dispatch reliability issues hurt PW1100G sales.

GE has a CMC coating issue reducing their overhaul intervals too:
http://airsoc.com/articles/view/id/59f7 ... lity-issue

So it will be a race to promised maintenance expenses to determine future sales. Alas, the loss of future Indigo airlines orders will hurt Pratt more than gaining Frontier. 43.8% Pratt, 56.2% CFM will probably be 60/40 before Pratt can sell enough more to even it out.

I also expect future A220 orders in respectable numbers The smaller pure power engines are doing very well now too.

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 6:30 pm

Is the dispatch reliability due to engines actually performing better or improved predictive tools allowing scheduled changes to head off an unscheduled event?

I get the sense that the GTF still has more frequent engine changes than the CEO or LEAP. If Pratt can tell an operator an engine needs to be changed in the next 100 flight hours and they have a spare engine available it will not effect dispatch reliability numbers but is far from ideal for an airline to be changing engines before the normal schedule.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 6:31 pm

lightsaber wrote:
I also expect future A220 orders in respectable numbers.

Lightsaber


So do I expect the same for the E2 family too !!!
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 7:18 pm

Now make wide body engines again. 787NG with only PW power like how GE weasled their way onto the 747-8 and 777-300ER
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 7:45 pm

UA444 wrote:
Now make wide body engines again. 787NG with only PW power like how GE weasled their way onto the 747-8 and 777-300ER


I also want to the see the tech scaled up but I think PW has a better chance at the A350NEO.. Since RR is the only current option.. I'm sure AB would welcome a second choice.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 9:51 pm

GTF technology was a major breakthrough and it looks like it still has a lot to offer. I can only imagine a four-engine wide-body with a pair of PW1100G accompanied by the PW1700G on the outermost part of the wings. Silence, lightness and a small landing gear.

How much would you pay extra to cross the Pacific with a four-engine aircraft?
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 18, 2021 10:16 pm

Nean1 wrote:
How much would you pay extra to cross the Pacific with a four-engine aircraft?


The same as anyone else: $0.00
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 5:24 am

Dispatch reliability is only one measure. They have only fixed the early problems that they encountered, after having said that the engine had been under development for 20 years and was ready for EIS. Not confidence inspiring.

Now, the problems will move to the next least reliable components and systems. Reliability is a work in progress.....and PW has been less than impressive in the Pw4000 vs CF6 competition in the past. I am very interested in overhaul intervals. GE/CFM is king until they aren't.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 11:06 am

DCA350 wrote:
UA444 wrote:
Now make wide body engines again. 787NG with only PW power like how GE weasled their way onto the 747-8 and 777-300ER


I also want to the see the tech scaled up but I think PW has a better chance at the A350NEO.. Since RR is the only current option.. I'm sure AB would welcome a second choice.

RR has an exclusivity agreement on the A350 (and A330neo). GE has an exclusivity agreement on the 777x. The 787 is the only current modern wide body without any such agreements. Even without those agreements PW wouldn’t jump from PW1000G, which tops out at around ~35k lbf thrust to an engine with ~85k+ lbf of thrust necessary for the A350.

Next application would probably be a NMA if ever gets launched.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 3:58 pm

EMBSPBR wrote:
lightsaber wrote:
I also expect future A220 orders in respectable numbers.

Lightsaber


So do I expect the same for the E2 family too !!!

I do expect more E2 orders. The lease placements have been encouraging.

Alas, Pratt had to improve the engine dispatch reliability before sales of anything GTF. Now they have overhaul intervals, but that is fixable via PiP and contract terms in new orders.

The E2 needs a large new customer. By this I mean 60+ aircraft. I like to use the Boeing 717 as an analogy. During production they only had AirTran as a large order and a few added airlines that were respectable, but did order enough to develop enough repairs. The volume sold *barely* kept enough spares in production (mostly thanks to DC-9/MD-80 and BMR-700 commonality).

The one large buyer for the E2 is Azul. A bit broader sales than the 717, but same order of magnitude (I use a factor of 3 to break out to new economics). It has great commonality on engines and airframes, subsystems are new...

For the A220, we have:
Delta (develops repairs)
Breeze (unknown, no service, yet)
JetBlue (not known for developing repairs)
AirFrance (develops repairs)

The A220 has good economy of scale and shares engines with the E2. Everything is new, which is why dispatch reliability was poor in 2019, but now excellent.

By sharing so much between the PW1500G, same engine PW1900G, PW815/14, and PW812 Pratt has taken the "maintain commonality" out if the BR-700 handbook to ensure long term support.

I'm a bit sad the PW1200G and PW1700G seem dead in the water. Oh well, ignoring scope does that.

We cannot ignore the business jet engines. Today they keep small core PurePower engine parts going through the vendors. Long term, they will ensure spares for 40+ years.

Today, the GTFs give those business cores more volume, controlling costs for the business jet engines. I'm sure the synergy helped sell G500/600 and 6x.

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 4:05 pm

SteelChair wrote:
Dispatch reliability is only one measure.
Now, the problems will move to the next least reliable components and systems.


This was my question at first instance.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 5:19 pm

Polot wrote:
DCA350 wrote:
UA444 wrote:
Now make wide body engines again. 787NG with only PW power like how GE weasled their way onto the 747-8 and 777-300ER


I also want to the see the tech scaled up but I think PW has a better chance at the A350NEO.. Since RR is the only current option.. I'm sure AB would welcome a second choice.

RR has an exclusivity agreement on the A350 (and A330neo). GE has an exclusivity agreement on the 777x. The 787 is the only current modern wide body without any such agreements. Even without those agreements PW wouldn’t jump from PW1000G, which tops out at around ~35k lbf thrust to an engine with ~85k+ lbf of thrust necessary for the A350.

Next application would probably be a NMA if ever gets launched.


I agree its unlikely they will jump straight into the WB space. However addressing the A350 I believe the exclusivity deal is only for the A35K. There was rumors GE could offer an engine for the other models.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 5:53 pm

EMBSPBR wrote:
SteelChair wrote:
Dispatch reliability is only one measure.
Now, the problems will move to the next least reliable components and systems.


This was my question at first instance.

Agreed, but dispatch reliability costs a lot if sub par. With predictive maintenance algorithms, they will constantly be improving components in the engines and airframes.

It took Pratt some time, but with dependable engines, sales will be much easier. When you miss dispatch reliability, life is crazy for the engine engineers.

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 7:25 pm

DCA350 wrote:
Polot wrote:
DCA350 wrote:

I also want to the see the tech scaled up but I think PW has a better chance at the A350NEO.. Since RR is the only current option.. I'm sure AB would welcome a second choice.

RR has an exclusivity agreement on the A350 (and A330neo). GE has an exclusivity agreement on the 777x. The 787 is the only current modern wide body without any such agreements. Even without those agreements PW wouldn’t jump from PW1000G, which tops out at around ~35k lbf thrust to an engine with ~85k+ lbf of thrust necessary for the A350.

Next application would probably be a NMA if ever gets launched.


I agree its unlikely they will jump straight into the WB space. However addressing the A350 I believe the exclusivity deal is only for the A35K. There was rumors GE could offer an engine for the other models.

RR/Airbus signed an exclusivity deal covering the A359 back in March: https://www.reuters.com/article/us-roll ... SKBN2B32A5
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 19, 2021 7:44 pm

Glad PW worked out the reliability issues. The potential of GTF technology is impressive.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Thu May 20, 2021 4:53 am

Polot wrote:
DCA350 wrote:
Polot wrote:
RR has an exclusivity agreement on the A350 (and A330neo). GE has an exclusivity agreement on the 777x. The 787 is the only current modern wide body without any such agreements. Even without those agreements PW wouldn’t jump from PW1000G, which tops out at around ~35k lbf thrust to an engine with ~85k+ lbf of thrust necessary for the A350.

Next application would probably be a NMA if ever gets launched.


I agree its unlikely they will jump straight into the WB space. However addressing the A350 I believe the exclusivity deal is only for the A35K. There was rumors GE could offer an engine for the other models.

RR/Airbus signed an exclusivity deal covering the A359 back in March: https://www.reuters.com/article/us-roll ... SKBN2B32A5


Thanks for the Update missed this.. Guess Ultrafan will probably be the only option for the NEO too..
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Thu May 20, 2021 12:30 pm

ElroyJetson wrote:
Glad PW worked out the reliability issues. The potential of GTF technology is impressive.

While there is some work to go (see above posts of mine), dispatch reliability is expensive when bad. That requires more spare aircraft, compensation, and planning reduced schedules. While the last probably wasn't a bit deal in 2020 due to lockdowns, it certainly would impact purchasing decisions. I am of the opinion Pratt lost potential sales in prior years due to the initial issues. Now that the engines are dispatching, they will sell.

Now others point out subsystems and such must be fixed. I agree. No one wants extra work at the A checks. No airline wants to be buying extra components to keep the fleet going. Predictive maintenance allows more trouble to not effect the fleet by predicting issues for component removal and replacement. So this step 1. But a minimum required step.

I'm certain this resulted in Indigo switching to the LEAP. :cry2: I speculate it effected other sales campaigns.

PiPs will be critical. We know GE is building CMC capability, Pratt is too, but further behind in timeline for service:
https://www.compositesworld.com/article ... h-carolina

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Thu May 20, 2021 2:01 pm

UA444 wrote:
Now make wide body engines again. 787NG with only PW power like how GE weasled their way onto the 747-8 and 777-300ER

It was cold hard cash that got GE the 77W exclusive. Not sure if PW is willing to go that route. Not sure today's GE would either. At that point in time they had invested a LOT in the GE90 Mk1 and it was not selling. They needed a proof point, so they doubled down on GE90-115B. The rest is history.

lightsaber wrote:
I'm certain this resulted in Indigo switching to the LEAP. :cry2: I speculate it effected other sales campaigns.

Indigo seemed to bear the brunt of the GTF problems with IFSDs, groundings, and the local regulator breathing down their neck. No doubt that affected other sales.
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Thu May 20, 2021 3:02 pm

lightsaber wrote:
ElroyJetson wrote:
Glad PW worked out the reliability issues. The potential of GTF technology is impressive.

While there is some work to go (see above posts of mine), dispatch reliability is expensive when bad. That requires more spare aircraft, compensation, and planning reduced schedules. While the last probably wasn't a bit deal in 2020 due to lockdowns, it certainly would impact purchasing decisions. I am of the opinion Pratt lost potential sales in prior years due to the initial issues. Now that the engines are dispatching, they will sell.

Now others point out subsystems and such must be fixed. I agree. No one wants extra work at the A checks. No airline wants to be buying extra components to keep the fleet going. Predictive maintenance allows more trouble to not effect the fleet by predicting issues for component removal and replacement. So this step 1. But a minimum required step.

I'm certain this resulted in Indigo switching to the LEAP. :cry2: I speculate it effected other sales campaigns.

PiPs will be critical. We know GE is building CMC capability, Pratt is too, but further behind in timeline for service:
https://www.compositesworld.com/article ... h-carolina

Lightsaber


Thank you for the link provided. I would say a must read for those interested in the evolution of jet turbine tech. I have always been a Pratt fan. I believe CMC will continue to be an emerging technology used to improve jet turbine efficiency. The clear benefits out weigh the considerable costs and difficulty machining.

As you said, GE has been the industry leader in CMC. I was not aware how aggressively Pratt is working to gain parity with GE in this area. I think this is obviously good for Pratt, but also good for the entire industry.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Thu May 20, 2021 4:48 pm

ElroyJetson wrote:
Thank you for the link provided. I would say a must read for those interested in the evolution of jet turbine tech. I have always been a Pratt fan. I believe CMC will continue to be an emerging technology used to improve jet turbine efficiency. The clear benefits out weigh the considerable costs and difficulty machining.

As you said, GE has been the industry leader in CMC. I was not aware how aggressively Pratt is working to gain parity with GE in this area. I think this is obviously good for Pratt, but also good for the entire industry.

People seem to forget that PW has had exclusives on the F-22 and F-35 engines and these drive tech into their civilian offerings:

Various sources report that Pratt & Whitney already manufactures CMC exhaust nozzles for the F135 engine used to power the F-35 Joint Strike Fighter.

I found all the info about the long-awaited updated engine for the A321XLR to be very interesting:

Leeham News and Analysis posted its thoughts based on an interview with Pratt & Whitney senior vice president of sales, marketing and customer support, Rick Deurloo. In the March 30, 2020 posting, author Scott Hamilton explained that Pratt & Whitney is developing “the next generation GTF,” an advancement over the current version, with more thrust and better economics. “We have been discussing with Airbus for some time an improvement to the current configuration or our expected configuration,” Deurloo added. Hamilton continued, “PW has been in conversation with Airbus for the last few years about an engine that will take configuration at the end of this year. PW planned to announce the name of the engine at the now-canceled [2020] Farnborough Air Show.” (Emphasis added.) Hamilton’s summary of this new engine:
New name, better economics, better durability.
• Designed for the A321XLR, but greater flexibility.
• Fixing current issues.

I guess I missed the Leeham piece, didn't realize they planned to give it a new name. Up to now it was being referred to as a PIP.

This “new engine” is not just the set of fixes for the PW1000G’s current issues, as Deurloo explains in the Leeham post: “There’s been a lot of energy and attention on engineering and development right now around fixing the current motor to where we need it to be. We have everything in place to go do that … in the third block quarter this year [2020, emphasis added]. I think it’s important, because then it talks about what’s next. It sets us up for where we’re going.”

“We think to take that engine, and especially when you pair it up with it with the XLR, which is why Airbus pushed us pretty hard on this, it really is a differentiator for that airplane, for that market, for its capability,” said Deurloo in the Leeham post. Hamilton then noted: “Low-rate production is targeted for 4Q-2022. Airbus’ planned EIS [entry into service] for the XLR is 2023. Within 18-24 months, the new engine will be 100% Pratt standard, Deurloo said.”

Seems the "new engine" will replace the current product entirely in 2024-5 or so?

Yet TFA says:

CFM president and CEO Gaël Méheust, in a November 2019 AINonline article by Chris Kjelgaard, said Airbus had indicated the LEAP 1A exactly meets the thrust, fuel-efficiency and dispatch-reliability requirements of the A321 XLR with no further changes.

So PW is hyping up a "new engine" at the same time CFM is saying ours is already good enough.

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Fri May 21, 2021 7:27 pm

Revelation wrote:
ElroyJetson wrote:
Thank you for the link provided. I would say a must read for those interested in the evolution of jet turbine tech. I have always been a Pratt fan. I believe CMC will continue to be an emerging technology used to improve jet turbine efficiency. The clear benefits out weigh the considerable costs and difficulty machining.

As you said, GE has been the industry leader in CMC. I was not aware how aggressively Pratt is working to gain parity with GE in this area. I think this is obviously good for Pratt, but also good for the entire industry.

People seem to forget that PW has had exclusives on the F-22 and F-35 engines and these drive tech into their civilian offerings:

Various sources report that Pratt & Whitney already manufactures CMC exhaust nozzles for the F135 engine used to power the F-35 Joint Strike Fighter.

I found all the info about the long-awaited updated engine for the A321XLR to be very interesting:

Leeham News and Analysis posted its thoughts based on an interview with Pratt & Whitney senior vice president of sales, marketing and customer support, Rick Deurloo. In the March 30, 2020 posting, author Scott Hamilton explained that Pratt & Whitney is developing “the next generation GTF,” an advancement over the current version, with more thrust and better economics. “We have been discussing with Airbus for some time an improvement to the current configuration or our expected configuration,” Deurloo added. Hamilton continued, “PW has been in conversation with Airbus for the last few years about an engine that will take configuration at the end of this year. PW planned to announce the name of the engine at the now-canceled [2020] Farnborough Air Show.” (Emphasis added.) Hamilton’s summary of this new engine:
New name, better economics, better durability.
• Designed for the A321XLR, but greater flexibility.
• Fixing current issues.

I guess I missed the Leeham piece, didn't realize they planned to give it a new name. Up to now it was being referred to as a PIP.

This “new engine” is not just the set of fixes for the PW1000G’s current issues, as Deurloo explains in the Leeham post: “There’s been a lot of energy and attention on engineering and development right now around fixing the current motor to where we need it to be. We have everything in place to go do that … in the third block quarter this year [2020, emphasis added]. I think it’s important, because then it talks about what’s next. It sets us up for where we’re going.”

“We think to take that engine, and especially when you pair it up with it with the XLR, which is why Airbus pushed us pretty hard on this, it really is a differentiator for that airplane, for that market, for its capability,” said Deurloo in the Leeham post. Hamilton then noted: “Low-rate production is targeted for 4Q-2022. Airbus’ planned EIS [entry into service] for the XLR is 2023. Within 18-24 months, the new engine will be 100% Pratt standard, Deurloo said.”

Seems the "new engine" will replace the current product entirely in 2024-5 or so?

Yet TFA says:

CFM president and CEO Gaël Méheust, in a November 2019 AINonline article by Chris Kjelgaard, said Airbus had indicated the LEAP 1A exactly meets the thrust, fuel-efficiency and dispatch-reliability requirements of the A321 XLR with no further changes.

So PW is hyping up a "new engine" at the same time CFM is saying ours is already good enough.

I'm glad I never went into marketing...

I couldn't do marketing either. Pratt has the option if a 3.5:1 gearbox which will help. Both engines for the A321xLR are too optimized for the 2-hour mission. I also suspect Pratt will put in variable cycle tech (variable fan, possibly variable turbine cooling).

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Fri May 21, 2021 8:11 pm

There are more A321neo with GTF than LEAP, the advantage of the LEAP is on the A320neo.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Fri May 21, 2021 10:14 pm

mjoelnir wrote:
There are more A321neo with GTF than LEAP, the advantage of the LEAP is on the A320neo.



I found an article by Air insight that states exactly that. LEAP appears to have lower operating costs on the A320Neo primary because of maintenance costs even though PW GTF has slightly better fuel burn. Air Insight explains how they got their data which is primarily from Frontier. They also state the PW GTF is more cost effective than LEAP on the A321Neo primary because of the longer stage lengths the A321Neo flies. This data is primarily from HA.

Here is the link to the article. https://airinsight.com/cfm-leap-vs-pw-gtf/

A competing piece from Forbes claims the PW GTF saves 100 gallons of fuel per hour over the LEAP and implies due to improvements in reliability made by Pratt the GTF now has lower operating costs than the LEAP. If the 100 gallon fuel savings number is accurate than with 10 hours utilization a day the GTF saves 1,000 gallons a day over the LEAP. That is certainly not insignificant. A link to the Forbes article.


https://www.forbes.com/sites/lorenthomp ... d787ce1655


So my question is this. Which story is correct? Does the PW GTF now have lower operating costs than the LEAP overall, or does it depend on stage length, aircraft, or other variables?
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Fri May 21, 2021 10:27 pm

ElroyJetson wrote:
Does the PW GTF now have lower operating costs than the LEAP overall, or does it depend on stage length, aircraft, or other variables?

Serious question: Who do we think would have the data to determine this? Airbus itself perhaps, and maybe a leasing company who owns both A320 and A321 with both GTF and LEAP? Are there any leasing firms who took the four different combinations? Do they (Airbus and leasing companies) get access to the fuel burn data or is that customer proprietary data?

Follow-up: Would they release that data?

Not trying to be a smart *ss, I really don't know.

I do know we don't generally get a lot of fuel burn data, and what we get seems to be snapshots of data in cruise, so would be hard to draw the detailed conclusions you are asking for.
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Fri May 21, 2021 10:36 pm

Revelation wrote:
ElroyJetson wrote:
Does the PW GTF now have lower operating costs than the LEAP overall, or does it depend on stage length, aircraft, or other variables?

Serious question: Who do we think would have the data to determine this? Airbus itself perhaps, and maybe a leasing company who owns both A320 and A321 with both GTF and LEAP? Are there any leasing firms who took the four different combinations? Do they (Airbus and leasing companies) get access to the fuel burn data or is that customer proprietary data?

Follow-up: Would they release that data?

Not trying to be a smart *ss, I really don't know.

I do know we don't generally get a lot of fuel burn data, and what we get seems to be snapshots of data in cruise, so would be hard to draw the detailed conclusions you are asking for.


Indigo partners has a mix amongst their airlines. And within that group, frontier switched from LEAP to Pratt for future deliveries beginning in 2022 iirc. Not to be confused with IndiGo airlines who switched from Pratt to LEAP. Anyway, I’m sure both of them have some good data.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sat May 22, 2021 12:56 am

JoseSalazar wrote:
Revelation wrote:
ElroyJetson wrote:
Does the PW GTF now have lower operating costs than the LEAP overall, or does it depend on stage length, aircraft, or other variables?

Serious question: Who do we think would have the data to determine this? Airbus itself perhaps, and maybe a leasing company who owns both A320 and A321 with both GTF and LEAP? Are there any leasing firms who took the four different combinations? Do they (Airbus and leasing companies) get access to the fuel burn data or is that customer proprietary data?

Follow-up: Would they release that data?

Not trying to be a smart *ss, I really don't know.

I do know we don't generally get a lot of fuel burn data, and what we get seems to be snapshots of data in cruise, so would be hard to draw the detailed conclusions you are asking for.


Indigo partners has a mix amongst their airlines. And within that group, frontier switched from LEAP to Pratt for future deliveries beginning in 2022 iirc. Not to be confused with IndiGo airlines who switched from Pratt to LEAP. Anyway, I’m sure both of them have some good data.


Indigo partners had own information on the GTF and LEAP, and Frontier switched to GTF.
IndiGo had own information on the GTF only, before they switched to LEAP. But they were also the airline with most trouble with the GTF.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sat May 22, 2021 1:38 am

The rumor has always been the GTF has slightly better fuel burn than the LEAP. But honestly, I do not know. As Revelation said, Airbus, some lessors, and maybe a handful of airlines know. But it is an interesting question.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sat May 22, 2021 2:47 pm

ElroyJetson wrote:
mjoelnir wrote:
There are more A321neo with GTF than LEAP, the advantage of the LEAP is on the A320neo.



I found an article by Air insight that states exactly that. LEAP appears to have lower operating costs on the A320Neo primary because of maintenance costs even though PW GTF has slightly better fuel burn. Air Insight explains how they got their data which is primarily from Frontier. They also state the PW GTF is more cost effective than LEAP on the A321Neo primary because of the longer stage lengths the A321Neo flies. This data is primarily from HA.

Here is the link to the article. https://airinsight.com/cfm-leap-vs-pw-gtf/

A competing piece from Forbes claims the PW GTF saves 100 gallons of fuel per hour over the LEAP and implies due to improvements in reliability made by Pratt the GTF now has lower operating costs than the LEAP. If the 100 gallon fuel savings number is accurate than with 10 hours utilization a day the GTF saves 1,000 gallons a day over the LEAP. That is certainly not insignificant. A link to the Forbes article.


https://www.forbes.com/sites/lorenthomp ... d787ce1655


So my question is this. Which story is correct? Does the PW GTF now have lower operating costs than the LEAP overall, or does it depend on stage length, aircraft, or other variables?

It will depend on over-haul intervals. The LEAP is designed for a longer overhaul interval. I couldn't find the link, so take as my opinion. Now, right now both are having to overhaul combustors too early, so this is theory.

But ideally, the LEAP will stay on for more cycles, so for mission lengths below 2.5 hours it has the cost advantage per my back of the envelope math. For missions lengths above 2.5 hours, the PW1100G should have the mission cost advantage.

Pratt also intentionally over-optimized the PW1100G for the A321. It suffers less of a wear penalty on the big plane (goal was no reduction in over-haul interval). So on the A321, there should be no maintenance penalty for the PW1100G vs. the LEAP-1A. So for JetBlue with long NorthEast to Flordia or TCON flights, the PW1100G makes sense for both aircraft. For Hawaiian, with their naturally long missions, the PW1100G makes sense. For short haul, that varies.

It also depends on when you base the data. Pratt improved dramatically during 2020 (PiPs were implemented).

Basically, Pratt costs more per takeoff due to shorter over-haul intervals.
LEAP costs more per hour due to fuel burn. My back of the envelope math has 2.5 hours on the A320NEO and about 1.75 hours on the A321NEO as break even.

Neither are good engines on the A319NEO (just too large to be efficient), hence my fandom for the A220-300.

The LEAP-1B is a very different engine. Far too optimized for shorter missions (a requirement of the fan diameter constraints). So better weight, better climb fuel burn, with the natural penalty of a smaller fan of worse cruise fuel efficiency. So we can go further that the MAX, in part thanks to the higher limit of validity in cycles (110,000 FC vs. 60,000 of the NEO) is perfect for short hops, the A320 NEO with LEAP owns the 2 to 2.5 hour missions, and Pratt's PW1100G should dominate on 2.5 hours plus.

Now obviously negotiations with the airlines on part costs, repairs, will shift the lines (they are not hard boundaries, but rather a rule of thumb). Engine PiPs, such as CMCs, will drastically change the rankings. But the LEAP-1B will always be optimized better for short missions than the LEAP-1A (I assume both keep pace at the same level of tech insertion). The PW1100G will always have a more efficient low turbine and that really helps at cruise (when pared to a large fan). So if LEAP has PiPs before Pratt, it will shift the mission hours, but for say HA, they will still have the advantage sticking with Pratt. The same with Pratt, while PiPs should extend over-haul intervals and reduce fuel burn, it is unlikely to overcome the LEAPs per takeoff maintenance cost advantage and thus the dividing line will shift, but not disapear.

We'll argue the engines.

The PW1500G is optimized for the 1 hour mission (great climb fuel burn at the trade of less optimum cruise fuel burn). If it seems like I am obsessed on mission length, every engine is optimized at design for a certain mission length. While Airbus mandated 2 hours on the A320NEO, the different architectures have strengths that naturally plan shorter flights or longer flights. To optimize for longer missions the fan diameter increases which forces a larger low turbine and with the growth in the nacelle results in much higher weight, being further off the optimum in climb, so for shorter mission there is always more climb fuel burn, but less cruise fuel burn. One just sees a marked advantage at the design mission length.

Take the 777-200ER. Now I have no link, so take this as rumor. But RR intentionally optimized for a shorter mission (~4,000 nm) than Pratt or GE (~5,000nm). You might go, but wait, that was a 7,400nm aircraft, wouldn't they optimize for the full mission? Never. Most missions are shorter. It terns out, in part for BA's extensive TATL flights around 4,000nm, RR made the correct optimization (higher MTOW used for cargo more than range). The same trade was made on the A330, albeit 1,000nm short on RR vs. Pratt (in my opinion, GE really wasn't an optimized engine for that platform, more what engine could be used on the platform early as it really was at the limits of the CF6 architecture). The climb fuel burn savings really helped RR sell. e.g., EK on flights to India.

When doing a sales campaign, one might weigh 200+ city pairs for an airline. Now for say LH, FRA to the US east Coast will weigh more than a theoretical mission to Bali, but they will both be in their widebody engine selection decision matrix. When you look at the system cost, engine selection tends to go to the engine that can do the longer mission with the desired payloads, but then has the lowest costs on the bulk of the missions, which tend to be shorter. That is just my experience, YMMV. The question is, where is the mission length for that airline? JetBlue and Hawaiian fly long missions. European airlines tend to fly short missions.

Frontier switching to Pratt on the A320NEO is... interesting on so many pages. While they just might be buying for the A321NEO, the fact it saves money on longer missions will make more longer missions profitable and thus the airline will be more competitive there. So one would expect more long missions to naturally fall out of this engine selection. The opposite for Indigo switching to the LEAP. With better 1.75 to 2.5 hour economics, one would expect the LEAP powered A320NEOs to find their way naturally onto those very profitable (in India) missions and thus Indigo to shift to a more domestic expansion as a result of engine selection. I would expect the Pratt powered A321NEOs to find their way onto longer missions both for gauge and that fuel savings is a nice fringe benefit with them flying outside their maintenance penalty range.

This is one reason I'm excited for an A220-500. It is just better optimized for short missions than the A320NEO. So airlines that fly a lot of short missions should love it. Until then, the A220-300. :spin: Or even smaller gauge with the E2 family.

Take LH, they bought the A320NEO with both engines. I would expect them to do some mix and match for benchmarking, but I would expect the Pratt planes to fly longer missions to save on fuel and the LEAP to fly shorter to save on maintenance. Now economics means putting all Pratt at one base and CFM at the other, so perhaps we won't see enough differentiation by mission length. Just put the CFM at the base with higher cycles and decision is made.

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sun May 23, 2021 1:42 am

I found a fascinating link on aircraft maintenance costs. I started reading it as a review and then look at slide 147
http://www.aircraftmonitor.com/uploads/ ... ers_v1.pdf

A very interesting estimate (ignore slide 146, it is missing some costs that are better represented in the next slide). However, there is an assumption of equal time on wing for the LEAP and PW1100G and that should not be. One would expect the other parts of the leap to last longer. (Both are sucking wind on combustor durability right now.)

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sun May 23, 2021 5:50 pm

Why is LEAP 1B better for shorter flights? Both shafts rotate faster about 600-800 rpm than on 1A, which is indeed good or turbine efficiency, but 1A has aditional two stages of LPT, so efficiency is gained different way. From maintenance point of view, whet it turn faster it will probably wear faster. Today I met one MAX8 after ferry flight and I was able to check fuel consumption, flight time was 6:56 and fuel used 12990kg.Amazing
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sun May 23, 2021 6:05 pm

milhaus wrote:
Why is LEAP 1B better for shorter flights? Both shafts rotate faster about 600-800 rpm than on 1A, which is indeed good or turbine efficiency, but 1A has aditional two stages of LPT, so efficiency is gained different way. From maintenance point of view, whet it turn faster it will probably wear faster. Today I met one MAX8 after ferry flight and I was able to check fuel consumption, flight time was 6:56 and fuel used 12990kg.Amazing

The two additional LPT stages and the bigger fan (and thus bigger nacelle and containment structure) all add weight, and the bigger fan adds frontal drag as well.

All this pays off on longer flights (bigger fan chews through more air), but not on shorter flights (extra weight adds fuel burn during climb).

That is why LS's post is focused on stage length.

Nice info on the ferry flight, but everyone should keep in mind fuel burn is low when the plane flies without pax/bags/cargo.
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sun May 23, 2021 6:24 pm

EMBSPBR wrote:
SteelChair wrote:
Dispatch reliability is only one measure.
Now, the problems will move to the next least reliable components and systems.


This was my question at first instance.


We'll have to wait and see. If the last 30-40 years of history is any indication, Pratt will not be able compete on reliability and durability. The 2037 has never achieved RR level of reliability, and the 4000 has never achieved CF6 level of performance (reliability and fuel burn). Then again, GEAE seems somewhat humbled compared to the past, and Pratt is benefitting from government handouts in the form of their refusal to compete F35 engines.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sun May 23, 2021 7:58 pm

ElroyJetson wrote:

A competing piece from Forbes claims the PW GTF saves 100 gallons of fuel per hour over the LEAP and implies due to improvements in reliability made by Pratt the GTF now has lower operating costs than the LEAP. If the 100 gallon fuel savings number is accurate than with 10 hours utilization a day the GTF saves 1,000 gallons a day over the LEAP. That is certainly not insignificant. A link to the Forbes article.


https://www.forbes.com/sites/lorenthomp ... d787ce1655



Just one small correction. The Forbes article states that:
GTF engines are consistently demonstrating a savings of 100 gallons in aviation fuel for every flight hour compared with legacy engines


It doesn't mean that the GTF saves this amount a fuel compared with the LEAP which is not a legacy engine.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sun May 23, 2021 8:01 pm

To Revelation: off course, they were quite light for T/O, just two pilots and 17,5 tons of fuel, so probably around 60 tons. Btw it was 4400km acc to OAG.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Sun May 23, 2021 8:25 pm

lightsaber wrote:
It will depend on over-haul intervals. The LEAP is designed for a longer overhaul interval. I couldn't find the link, so take as my opinion. Now, right now both are having to overhaul combustors too early, so this is theory.

But ideally, the LEAP will stay on for more cycles, so for mission lengths below 2.5 hours it has the cost advantage per my back of the envelope math. For missions lengths above 2.5 hours, the PW1100G should have the mission cost advantage.

Pratt also intentionally over-optimized the PW1100G for the A321. It suffers less of a wear penalty on the big plane (goal was no reduction in over-haul interval). So on the A321, there should be no maintenance penalty for the PW1100G vs. the LEAP-1A. So for JetBlue with long NorthEast to Flordia or TCON flights, the PW1100G makes sense for both aircraft. For Hawaiian, with their naturally long missions, the PW1100G makes sense. For short haul, that varies.

It also depends on when you base the data. Pratt improved dramatically during 2020 (PiPs were implemented).

Basically, Pratt costs more per takeoff due to shorter over-haul intervals.


Engine OEM's exclude engines used 'outside contracted operational profiles' during the review period from stats, like RTO's, failure to observe start up and cool down procedures, hot/high, etc. The categories associated with PBTH supplementary payments.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 25, 2021 1:59 am

Revelation wrote:
milhaus wrote:
Why is LEAP 1B better for shorter flights? Both shafts rotate faster about 600-800 rpm than on 1A, which is indeed good or turbine efficiency, but 1A has aditional two stages of LPT, so efficiency is gained different way. From maintenance point of view, whet it turn faster it will probably wear faster. Today I met one MAX8 after ferry flight and I was able to check fuel consumption, flight time was 6:56 and fuel used 12990kg.Amazing

The two additional LPT stages and the bigger fan (and thus bigger nacelle and containment structure) all add weight, and the bigger fan adds frontal drag as well.

All this pays off on longer flights (bigger fan chews through more air), but not on shorter flights (extra weight adds fuel burn during climb).

That is why LS's post is focused on stage length.

Nice info on the ferry flight, but everyone should keep in mind fuel burn is low when the plane flies without pax/bags/cargo.

I would add that to minimize climb fuel burn a lower bypass ratio is desired. The LEAP-1A has a bypass ratio of 11:1 and the LEAP-1B 9:1. This means the low spool isn't struggling as much during climb and thus it will spin faster. Because it is spinning faster the low turbine efficiency is much higher, despite not having stages, and the climb fuel burn is improved. In cruise, that low spool is able to spin up to an optimum mach number and thus the -1A low spool is more efficient. Only during cruise does the -1A low spool get spinning fast enough to really take advantage of the added low turbine stages.

https://www.bangaloreaviation.com/2017/ ... e%20engine.

So now back to the GTF, how can it have decent climb efficiency? The gearbox. The low turbine is always in a much better mach# regime and thus it climbs well. Now the LEAP has variable turbine cooling, so that helps break the compromise I'm discussing. Where the LEAP excels is a lower maintenance cost per cycle. It takes a while flying to burn enough less fuel to make a difference in the flight costs.

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 25, 2021 12:59 pm

Thanks for clarification in performance side. Anyway from mtce side core on Leap 1B runs faster and most wear and damage occurs during high power settings, so it will probably wear faster than 1A
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 25, 2021 2:02 pm

milhaus,
While Mach# increase does increase erosion, temperature plays a far more critical role. Increasing Mach # 10% increases wear about 20%. Increasing temperature by 28C doubles wear. The most critical wear is end of climb. I can only do rough estimations, but I estimate end if climb wear is less on the -1B, but higher at takeoff giving similar life. One can trade cooling for Mach # erosion and that is a benefit until seal/bearing speed is an issue.

The advantage of the LEAP over the PW1100G is it has enhanced cooling during takeoff and climb that is cut for the low temperature cruise. That allows LEAP the greater cycle and hour durability, in my opinion.

That said, the GTF helps reduce fuel burn more during climb and cruise. Pratt needs to add variable turbine cooling. The best compromise is increase cooling in takeoff and climb then cut for cruise. Overall, a little more fuel burn the first 45 minutes of flight, break even by 60 to 75 minutes into the flight and from then on a benefit of 2% to 3% reduction in fuel burn and an increase in overhaul interval of 25% to 33% (less fuel savings, more overhaul interval, nothing is free).

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 25, 2021 3:20 pm

lightsaber wrote:
milhaus,
While Mach# increase does increase erosion, temperature plays a far more critical role. Increasing Mach # 10% increases wear about 20%. Increasing temperature by 28C doubles wear. The most critical wear is end of climb. I can only do rough estimations, but I estimate end if climb wear is less on the -1B, but higher at takeoff giving similar life. One can trade cooling for Mach # erosion and that is a benefit until seal/bearing speed is an issue.

The advantage of the LEAP over the PW1100G is it has enhanced cooling during takeoff and climb that is cut for the low temperature cruise. That allows LEAP the greater cycle and hour durability, in my opinion.

That said, the GTF helps reduce fuel burn more during climb and cruise. Pratt needs to add variable turbine cooling. The best compromise is increase cooling in takeoff and climb then cut for cruise. Overall, a little more fuel burn the first 45 minutes of flight, break even by 60 to 75 minutes into the flight and from then on a benefit of 2% to 3% reduction in fuel burn and an increase in overhaul interval of 25% to 33% (less fuel savings, more overhaul interval, nothing is free).

Very interesting that we have these differences that help highlight the pros and cons of various design choices.

Interesting that we have two different engines on the same airframe (A320neo) for easy comparison. Can show benefit of gear, benefit of variable turbine cooling, etc.

Interesting that we have two different versions of the same engine (LEAP 1A vs 1B) for easy comparison. Can show benefit of lower vs higher bypass ratio on climb vs cruise performance.

The next generation narrow bodies and their engines should make for interesting contrasts. Will the aviation industry find enough "greenwashing" to apply to avoid being forced into greener yet less physically efficient approaches to propulsion? Will we get one more iteration of the jet turbine? Will it be the last ever? So many thoughts to ponder.

It'd be interesting if we see green legislation kind of act like the US scope rules now do, favoring the preservation of older tech past its prime i.e. E1-175 with CF34 still rolling of the production line since it's still the most economically efficient approach to the US regional market yet would be dead without such scope rules.
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 25, 2021 4:00 pm

Revelation wrote:
lightsaber wrote:
milhaus,
While Mach# increase does increase erosion, temperature plays a far more critical role. Increasing Mach # 10% increases wear about 20%. Increasing temperature by 28C doubles wear. The most critical wear is end of climb. I can only do rough estimations, but I estimate end if climb wear is less on the -1B, but higher at takeoff giving similar life. One can trade cooling for Mach # erosion and that is a benefit until seal/bearing speed is an issue.

The advantage of the LEAP over the PW1100G is it has enhanced cooling during takeoff and climb that is cut for the low temperature cruise. That allows LEAP the greater cycle and hour durability, in my opinion.

That said, the GTF helps reduce fuel burn more during climb and cruise. Pratt needs to add variable turbine cooling. The best compromise is increase cooling in takeoff and climb then cut for cruise. Overall, a little more fuel burn the first 45 minutes of flight, break even by 60 to 75 minutes into the flight and from then on a benefit of 2% to 3% reduction in fuel burn and an increase in overhaul interval of 25% to 33% (less fuel savings, more overhaul interval, nothing is free).

Very interesting that we have these differences that help highlight the pros and cons of various design choices.

Interesting that we have two different engines on the same airframe (A320neo) for easy comparison. Can show benefit of gear, benefit of variable turbine cooling, etc.

Interesting that we have two different versions of the same engine (LEAP 1A vs 1B) for easy comparison. Can show benefit of lower vs higher bypass ratio on climb vs cruise performance.

The next generation narrow bodies and their engines should make for interesting contrasts. Will the aviation industry find enough "greenwashing" to apply to avoid being forced into greener yet less physically efficient approaches to propulsion? Will we get one more iteration of the jet turbine? Will it be the last ever? So many thoughts to ponder.

It'd be interesting if we see green legislation kind of act like the US scope rules now do, favoring the preservation of older tech past its prime i.e. E1-175 with CF34 still rolling of the production line since it's still the most economically efficient approach to the US regional market yet would be dead without such scope rules.

Pratt tried the PW1200G for the regional market. But Mitsubishi did not deliver. I personally think Breeze or Allegiant with P2P, limited frequency will take more and more of the small airport market. An E175 vs. A319CEO meant limited opportunity for Allegiant. An E175 vs an A220 at Breeze is less opportunity.

I think we are at a reduction in regional flying.

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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Tue May 25, 2021 7:25 pm

To Lightsaber: So core of 1B is cooler than 1A despite being faster? I think that both have same limit 1050 deg C, I have to check it to be sure.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 26, 2021 3:04 am

milhaus wrote:
To Lightsaber: So core of 1B is cooler than 1A despite being faster? I think that both have same limit 1050 deg C, I have to check it to be sure.

I'm talking end of climb, it should be.

I'm not talking EGR, but rather at end climb when the cooling is poor. A very specific wear condition that often determines engine wear.
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Wed May 26, 2021 11:32 pm

To build on my GTF discussion:
https://aviationweek.com/mro/aircraft-p ... ents-power

That is the best insight I have ever seen into debugging the GTFs.

So the dynamic issue, my take.
1. The new combustor liner partially solves the problem by making the part better able to take the dynamics.
2. There is a kit being developed (certified) on certain "speed" issues. I could be extrapolating too far, but I think that new parts are being added and updated software to solve the durability issues with the noise.

But that could just be my take.

Late edit:
So a mixture of ruggedness and control logic to achieve time on wing. I really like all the software. 90% of problems go away with good tuning. The issue is the time it takes to undertestand all the data.
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Thu May 27, 2021 6:40 am

Nean1 wrote:
GTF technology was a major breakthrough and it looks like it still has a lot to offer.


Yes, over 13,000 TFE731 engines have been produced since 1972. I don't have the numbers for the ALF502 / LF507 but they're not rare either.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Thu May 27, 2021 8:36 pm

Lightsaber: why cooling is better on lower bypass engine on t/c? And bact to GTF, how many parts are shared between different versions? I have not seen any PW1200/1400/1700 yet, but 1100/1500/1900 look very similar except fan size and oil tank location.
 
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Re: Pratt & Whitney GTF Engines Now Power More Than 1,000 Aircraft

Fri May 28, 2021 3:38 pm

milhaus wrote:
Lightsaber: why cooling is better on lower bypass engine on t/c? And bact to GTF, how many parts are shared between different versions? I have not seen any PW1200/1400/1700 yet, but 1100/1500/1900 look very similar except fan size and oil tank location.

The higher the bypass ratio, the lower the low spool rpm vs. optimal rpm. This means worse low turbine and compressor efficiency which must be made up by more fuel. As the wear is a mix of takeoff snd cruise, higher bypass, to take advantage of the cruise efficiency, requires a higher wear end of climb.
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