Moderators: jsumali2, richierich, ua900, PanAm_DC10, hOMSaR

 
User avatar
Revelation
Posts: 24622
Joined: Wed Feb 09, 2005 9:37 pm

Re: Airbus stops accepting PW1100G engines

Sat Feb 17, 2018 7:18 pm

fsabo wrote:
Revelation wrote:
zeke wrote:
The engine manufacturer has also committed to deliver the (fi)rst engines incorporating a (fi)x in April. That likely means GTF-powered A320neo deliveries will be halted for more than two months.

Thank you for the info, zeke.

I went to their web site and unfortunately it does not have the same article, but they warned that they are having web site problems.

Here April is mentioned...

https://www.flightglobal.com/news/artic ... fa-445968/

Thank you as well, fsabo.

The article says:

Airbus and P&W have submitted a mitigation plan to the regulatory authorities. If the latter approve, Airbus expects deliveries from P&W to resume in April.

Interesting about the plan approval (which I think was supposed to happen Friday?) and then Airbus communicating the date rather than Pratt.

Theseus wrote:
While I wish them to come as early as possible, I hope it will not be on the first of the month...

:bigthumbsup:

April has 30 days... Let's all hope it's not April 1st!

From what I've seen in corporate life, "in April" means "April 30th" and "resume" means "one unit".

Let's hope my cynicism is not justified.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
azjubilee
Posts: 3721
Joined: Sat Apr 29, 2000 5:26 am

Re: Airbus stops accepting PW1100G engines

Sat Feb 17, 2018 7:38 pm

FWIW... HA's grounded 321neo (N204HA) has two new engines and will re-enter service today. A 767 or 330 was filling in on that aircraft's line since the AD was announced. The other 321neo (N202HA) was not affected by the AD.
 
Newbiepilot
Posts: 3641
Joined: Tue Aug 30, 2016 10:18 pm

Re: Airbus stops accepting PW1100G engines

Sat Feb 17, 2018 8:07 pm

azjubilee wrote:
FWIW... HA's grounded 321neo (N204HA) has two new engines and will re-enter service today. A 767 or 330 was filling in on that aircraft's line since the AD was announced. The other 321neo (N202HA) was not affected by the AD.


Where did the engines come from?
 
azjubilee
Posts: 3721
Joined: Sat Apr 29, 2000 5:26 am

Re: Airbus stops accepting PW1100G engines

Sat Feb 17, 2018 8:27 pm

Newbiepilot wrote:
azjubilee wrote:
FWIW... HA's grounded 321neo (N204HA) has two new engines and will re-enter service today. A 767 or 330 was filling in on that aircraft's line since the AD was announced. The other 321neo (N202HA) was not affected by the AD.


Where did the engines come from?


Not sure, but from what I understand PW had spare engines in the USA.
 
Planesmart
Posts: 2891
Joined: Sun Dec 05, 2004 3:18 am

Re: Airbus stops accepting PW1100G engines

Sat Feb 17, 2018 9:04 pm

WkndWanderer wrote:
How much in engine concession payments does Airbus have to make vs. P&W? The portion of the Airbus investor presentation that says they paid out €7 billion in engine concessions in 2017 on commercial aircraft surprised me a bit.

Engine concessions has a broader meaning than customer compensation for defective, under-performing, late delivery..... Works out to an average of 10m per aircraft based on 2017 deliveries. On NB's, that's buy one engine, get one free. But as no issues with CEO engines, if you scale for deliveries, that's one free engine with every delivered aircraft.

A significant proportion of engine purchases are made directly by the customer, especially for large customers, and/or customers placing large volume orders, who contract support, maintenance, MTBF, training, performance guarantees, etc. Those customers would usually lodge claims directly against the engine manufacturer.

Airbus liability still exists if they have made promises on the aircraft/engine combination (for example fuel efficiency), or if the engines were ready for fitting but the air frame wasn't, or if the customer is claiming air frame/engine testing or certification authorities were negligent.

Like air bags, to retain goodwill, businesses with the deepest pockets make good, and then look to extract reimbursement from insurers, suppliers, third parties, directors.....

At this stage, Airbus and others using the same engine, want the problem fixed, replacement good parts or engines for grounded aircraft, and flawless engines delivered for new aircraft deliveries.

PW priority should be to transfer intellectual property and other assets to a JV third party to quarantine claims. My money would have been for the white knight to be RR, as both companies are presently assisting each other resolve technical and component production volume issues. Or perhaps GE takes out PW, conditional on disposal of EA (which is in the process of being dissolved) and CFM interests, which now seems less likely as GE is trying to sell high performing business units. Or could PW find itself back with it's IAE partners, this time as the junior?

Outwardly all love and goodwill, for now, but PW division as part of UTC will never be the same again.
 
lowbank
Posts: 511
Joined: Wed Mar 25, 2009 9:10 pm

Re: Airbus stops accepting PW1100G engines

Sat Feb 17, 2018 9:07 pm

Revelation wrote:
zeke wrote:
The engine manufacturer has also committed to deliver the (fi)rst engines incorporating a (fi)x in April. That likely means GTF-powered A320neo deliveries will be halted for more than two months.

Thank you for the info, zeke.

I went to their web site and unfortunately it does not have the same article, but they warned that they are having web site problems.

I got an email from them (that anyone can get after free registration) that has a similar but longer report.

With regard to the current problem, it says:

Pratt says an engineering change was made in mid-2017 to improve durability and introduced into revenue service on customer aircraft in December.

So it arose from an attempt to improve durability rather than a manufacturing process change.

It talks about the final resolution of issues with (a) the bearing seals and (b) the cumbustor, which both were also failed attempts to address durability issues.

For the bearing seals it says:

The chief change to the bearing housing is a switch from the liftoff seal used in the original design to a dry-runningface seal that becomes the standard configuration. The dry-running face seal consists of a rotating mating ring made from a carbide material and a carbon-graphite stationary ring. The faces are flat and held tightly together using magnets or springs to prevent oil leaking through, despite the high revolutions. The liftoff seal, on the other hand, incorporates grooves and wedges to channel a thin film of air between the sliding sealing faces, which creates aerodynamic lift.

“We originally went with a liftoff seal because we thought it would be more durable over time. It turns out the problem we discovered was that the software was misreading the altitude, so the bellows were not putting enough pressure on the carbon seal to create that air bubble. Sometimes it was putting too much pressure, which was causing the carbon flakes to go into the oil side,” a Pratt spokeswoman says. The resulting gap between the carbon air seal and associated seal plate allowed traces of metal particles to enter the oil system and trigger chip-detector warnings.

Pratt paved the way to the final fix by introducing an interim upgrade package in May 2017 that included the addition of a venturi tube to reduce the air pressure directed at the bearing compartment as well as associated modifications to the electronic engine control software to restrict the airflow. The tube was external to the compartment itself but integral to the carbon seal package.

“The improvement package performed better than we had hoped, except for engines that had higher time on them, which had to be reprioritized for overhaul,” Pratt says. The liftoff seal and the improvement package “bought us time to work out whether we needed to develop a permanent fix to the liftoff seal or go to a standard brush seal or dry-face design,” Pratt adds. “We decided to go with a dry-face design, and that’s now part of the standard bill of material.”

For the combustor change it says:

The revised combustor configuration is designed to address the durability problems that led to a rash of premature engine removals by two Indian-based A320neo operators, GoAir and IndiGo. “We have roughly doubled the number of air cooling holes and configured the density of the holes to the lower left of intake/outtake valve. We essentially had the density in the wrong place originally,” the engine maker says.

The revised design is expected to increase durability by a factor of five over the baseline. Although the interim fix fielded in 2017 appears to be adequate for non-harsh environments, the revised combustor design will now be standard to cope with operations in areas such as China, India and the Middle East. All the upgrades have been introduced to production engines and will be woven into engines coming through for overhaul.

So, lots of details on how they addressed the earlier issues, but not much about the current issue, other than the first fix is expected in April after two months of disruption to deliveries.

It sounds like these fixes should be long lasting. It is disappointing that they were not found earlier, but I guess they needed a substantial number of engines in mainline service till the problems were identified.

For those wondering about the earlier shaft bowing problem, https://www.flightglobal.com/news/artic ... lf-424321/ from April 2016 says:

P&W is further addressing the problem by applying a coating to some engine blades and strengthening the engine's third and fourth shaft bearings to prevent the harmonic vibration, Bromberg says.

"Then ultimately we are going to put coating on some of the blades that will improve the sealing function in the compressor," Bromberg says.

The third bearing seal is the one being discussed above.


That a comprehensive explanation.

I will get back in my box.
Every days a school day.
 
N212R
Posts: 331
Joined: Wed Dec 14, 2016 5:18 pm

Re: Airbus stops accepting PW1100G engines

Sat Feb 17, 2018 9:32 pm

P&W is further addressing the problem by applying a coating to some engine blades and strengthening the engine's third and fourth shaft bearings to prevent the harmonic vibration, Bromberg says.

"Then ultimately we are going to put coating on some of the blades that will improve the sealing function in the compressor," Bromberg says.


Lot of "coating" going on when it comes to their manufacturing issues. Just not convinced much of it isn't of the sugary variety.
 
WholaLottaLove
Posts: 55
Joined: Sat Sep 24, 2016 10:46 pm

Re: Airbus stops accepting PW1100G engines

Tue Feb 27, 2018 5:07 pm

According to UTX's (P&W parent) CEO, GTF production will be resumed next week. As far as I understand it, they simple switched back to the old knife-edge seal used in the original GTFs. I wonder if this is an actual long-term solution? The fix already got regulatory approval.
 
fsabo
Posts: 197
Joined: Fri Dec 04, 2015 8:41 pm

Re: Airbus stops accepting PW1100G engines

Tue Feb 27, 2018 5:36 pm

WholaLottaLove wrote:
According to UTX's (P&W parent) CEO, GTF production will be resumed next week. As far as I understand it, they simple switched back to the old knife-edge seal used in the original GTFs. I wonder if this is an actual long-term solution? The fix already got regulatory approval.


I do not think this is long term. I think it is good enough to keep aircraft flying while a long term solution is properly tested.
 
User avatar
Revelation
Posts: 24622
Joined: Wed Feb 09, 2005 9:37 pm

Re: Airbus stops accepting PW1100G engines

Tue Feb 27, 2018 5:46 pm

WholaLottaLove wrote:
According to UTX's (P&W parent) CEO, GTF production will be resumed next week. As far as I understand it, they simple switched back to the old knife-edge seal used in the original GTFs. I wonder if this is an actual long-term solution? The fix already got regulatory approval.

https://www.ainonline.com/aviation-news ... production from Feb 21st said:

Hayes told delegates at the Barclays Industrial Select conference in Miami Beach on Wednesday that the engine maker resumed GTF production last week and that new PW1100G-JM engines with the revised knife-edge seal configuration will be delivered to Airbus starting in early March.

So it would seem production resumed the week of Feb 11-17.

That article also says they've gone back to the earlier design.

Another interesting point:

PW1100G-JM engines have now accumulated approximately 300,000 flight hours in service and, together, all other PW1000G modes have accumulated approximately 200,000 flight hours, according to Hayes, who estimated the in-service GTF fleet will reach 1 million hours of accumulated flight time “later this year.” He added that “until we get to 1 million hours, it’s still a new engine.” However, “once we get to 1 million hours, we will have cleared most of the teething issues.”

Let's hope it's a smooth path to the 1M hour mark some time this year.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
User avatar
KarelXWB
Topic Author
Posts: 26968
Joined: Sun Jul 15, 2012 6:13 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 11:22 am

After PW1100G production has resumed in mid-February, Airbus has now resumed aircraft deliveries as well. Earlier this week the first P&W powered China Southern A321neo completed a customer acceptance flight and will be handover over later today. This also marks the first A321neo delivery in mainland China.

https://twitter.com/AerCapNV/status/969177505365135360

As pointed out above, P&W has simply reverted the knife-edge seal modification, and will re-introduce an improved design at a later stage. Note that the knife-edge seal modification was unrelated to the bearing and combustion chamber issues, so undoing this change won't revert the latest fixes. The knife-edge seal modification was part of 17 changes to "improve performance and durability":

"We have gone back to an earlier design on a knife-edge seal on the eight-stage compressor," Hayes told attendees at an investor conference. The modification was one of 17 changes put into place to improve performance and durability, and the other 16 are showing no signs of problems. Upgrading the affected fleet to address the knife-edge seal issue is expected to take a "few months," Hayes said.

The knife-edge seal issue is not related to other PW1000G-family anomalies that have held up production.


Ref http://www.mro-network.com/manufacturin ... few-months

As such, there is not going to be a 6 months delivery delay as some speculated earlier. However, while deliveries of new aircraft have resumed, addressing those 43 affected in-service engines will be time consuming.

For those who want a more in-dept article on the PW1100G #3 bearing seal and combustion chamber fixes that have been put in place last year, have a look at http://now.eloqua.com/es.asp?s=96691307 ... 8a7c4d72#2
What we leave behind is not as important as how we've lived.
 
User avatar
KarelXWB
Topic Author
Posts: 26968
Joined: Sun Jul 15, 2012 6:13 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 11:58 am

Newbiepilot wrote:
azjubilee wrote:
FWIW... HA's grounded 321neo (N204HA) has two new engines and will re-enter service today. A 767 or 330 was filling in on that aircraft's line since the AD was announced. The other 321neo (N202HA) was not affected by the AD.


Where did the engines come from?


Yes N204HA re-entered service on February 17. One can track it down at https://www.flightradar24.com/data/aircraft/n204ha

Replacement engines were picked up from the spare pool. Spare engines are not affected by the AD.

Newbiepilot wrote:
Will the good engines be going to Airbus to support deliveries or be sent to airlines to replacr engines on their grounded planes? The article i posted said priority is for airlines already delivered, so that may be causing the 6 month delivery delay. Airbus also stopped test flights


A combination of both. Hawaiian got engines from the spare pool, other airlines will get their in-service engines repaired in the field. P&W will also supply new engines to the spare pool, but Airbus should still get the bulk.

Newbiepilot wrote:
I read this article that talks about more compensation is going to IndiGo. It also reaffirms the 10 to 1 sales numbers from early 2017 for CFM vs PW on the A320neo. PW has won some orders in late 2017, but halting deliveries, grounding airplanes and suspending ETOPS may hurt sales.


The ETOPS restriction applies only to those 43 engines affected by the AD. All other 500 GTF engines that have been delivered since 2015/16 are still ETOPS approved.
What we leave behind is not as important as how we've lived.
 
Newbiepilot
Posts: 3641
Joined: Tue Aug 30, 2016 10:18 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 2:25 pm

KarelXWB wrote:
After PW1100G production has resumed in mid-February, Airbus has now resumed aircraft deliveries as well. Earlier this week the first P&W powered China Southern A321neo completed a customer acceptance flight and will be handover over later today. This also marks the first A321neo delivery in mainland China.

As pointed out above, P&W has simply reverted the knife-edge seal modification, and will re-introduce an improved design at a later stage. Note that the knife-edge seal modification was unrelated to the bearing and combustion chamber issues, so undoing this change won't revert the latest fixes. The knife-edge seal modification was part of 17 changes to "improve performance and durability":

"We have gone back to an earlier design on a knife-edge seal on the eight-stage compressor," Hayes told attendees at an investor conference. The modification was one of 17 changes put into place to improve performance and durability, and the other 16 are showing no signs of problems. Upgrading the affected fleet to address the knife-edge seal issue is expected to take a "few months," Hayes said.

The knife-edge seal issue is not related to other PW1000G-family anomalies that have held up production.


Ref http://www.mro-network.com/manufacturin ... few-months

As such, there is not going to be a 6 months delivery delay as some speculated earlier. However, while deliveries of new aircraft have resumed, addressing those 43 affected in-service engines will be time consuming.

For those who want a more in-dept article on the PW1100G #3 bearing seal and combustion chamber fixes that have been put in place last year, have a look at http://now.eloqua.com/es.asp?s=96691307 ... 8a7c4d72#2


Good news that production resumes. Not so good news that they went back to an older design with known problems, but at least production can resume.
 
User avatar
KarelXWB
Topic Author
Posts: 26968
Joined: Sun Jul 15, 2012 6:13 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 2:30 pm

Newbiepilot wrote:
Not so good news that they went back to an older design with known problems, but at least production can resume.


You may want to re-read the article.

The knife-edge seal issue is not related to other PW1000G-family anomalies that have held up production.


Reverting the knife-edge seal modification does not re-introduce the #3 bearing and combustion chamber issues.
What we leave behind is not as important as how we've lived.
 
Newbiepilot
Posts: 3641
Joined: Tue Aug 30, 2016 10:18 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 2:43 pm

KarelXWB wrote:
Newbiepilot wrote:
Not so good news that they went back to an older design with known problems, but at least production can resume.


You may want to re-read the article.

The knife-edge seal issue is not related to other PW1000G-family anomalies that have held up production.


Reverting the knife-edge seal modification does not re-introduce the #3 bearing and combustion chamber issues.


This is what it said

We have gone back to an earlier design on a knife-edge seal on the eight-stage compressor," Hayes told attendees at an investor conference. The modification was one of 17 changes put into place to improve performance and durability, and the other 16 are showing no signs of problems. Upgrading the affected fleet to address the knife-edge seal issue is expected to take a "few months," Hayes said.

Sounded to me like there was a known performance and durability issue
 
User avatar
KarelXWB
Topic Author
Posts: 26968
Joined: Sun Jul 15, 2012 6:13 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 3:01 pm

Newbiepilot wrote:
Sounded to me like there was a known performance and durability issue


Not every change needs to be related to "a problem".

In fact, the article doesn't say there was a problem with the knife-edge seal, so that is just speculation. It says performance and durability of 17 components are improved, which boils down to further increase of reliability and on-wing time. This may be part of ongoing improvements. As Revelation points out upthread, changes to components can be expected as long as the engine doesn't reach 1 million hours. As far as I know, all new engine models are getting some parts upgraded after entry into service, as part of the mature process.
What we leave behind is not as important as how we've lived.
 
fsabo
Posts: 197
Joined: Fri Dec 04, 2015 8:41 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 3:08 pm

Newbiepilot wrote:
KarelXWB wrote:
Newbiepilot wrote:
Not so good news that they went back to an older design with known problems, but at least production can resume.


You may want to re-read the article.

The knife-edge seal issue is not related to other PW1000G-family anomalies that have held up production.


Reverting the knife-edge seal modification does not re-introduce the #3 bearing and combustion chamber issues.


This is what it said

We have gone back to an earlier design on a knife-edge seal on the eight-stage compressor," Hayes told attendees at an investor conference. The modification was one of 17 changes put into place to improve performance and durability, and the other 16 are showing no signs of problems. Upgrading the affected fleet to address the knife-edge seal issue is expected to take a "few months," Hayes said.

Sounded to me like there was a known performance and durability issue


The main issues were the #3 bearing carbon seal and combustion chamber. If the knife edge seal will now become an issue remains to be seen. My interpretation of the situation is that a new knife edge seal design will be deployed but only after proper testing, and the the 'old knife edge seal' design is good enough to keep flying until that happens.
 
User avatar
TheRedBaron
Posts: 3276
Joined: Tue Mar 29, 2005 6:17 am

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 3:25 pm

Great news they are getting the problem fixed (temporarily) and production will resume, I wonder how much this will affect other programs that use the same engine...

Best Regards
TRB
The best seat in a Plane is the Jumpseat.
 
User avatar
AC02
Posts: 23
Joined: Mon Feb 01, 2016 11:20 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 01, 2018 7:40 pm

LockheedBBD wrote:
william wrote:
How does this effect the CS and E2?


Hard to say at this point. Bombardier, Embraer, and to a lesser extent Mitsubishi are going to have some serious trouble if it affects them as well.


https://www.flightglobal.com/news/artic ... es-445889/

Seems to be fine with CS, E2, and MRJ..
 
User avatar
Revelation
Posts: 24622
Joined: Wed Feb 09, 2005 9:37 pm

Re: Airbus stops accepting PW1100G engines

Thu Mar 15, 2018 10:53 pm

Newbiepilot wrote:
KarelXWB wrote:
Newbiepilot wrote:
Not so good news that they went back to an older design with known problems, but at least production can resume.

You may want to re-read the article.

The knife-edge seal issue is not related to other PW1000G-family anomalies that have held up production.

Reverting the knife-edge seal modification does not re-introduce the #3 bearing and combustion chamber issues.

This is what it said

We have gone back to an earlier design on a knife-edge seal on the eight-stage compressor," Hayes told attendees at an investor conference. The modification was one of 17 changes put into place to improve performance and durability, and the other 16 are showing no signs of problems. Upgrading the affected fleet to address the knife-edge seal issue is expected to take a "few months," Hayes said.

Sounded to me like there was a known performance and durability issue

In https://leehamnews.com/2018/03/14/pratt ... n-trouble/ Bjorn Fehrm gives us a run down of all the issues.

1) Rotor bowing issue
2) The third engine bearing "air riding" seal issue
3) Combustor chamber lining issue
4) High pressure compressor knife-edge seal issue

Earlier I didn't recognize (2) and (4) as distinct issues, but Bjorn and the quotes you've given above has cleared that up.

Bjorn's description is excellent. I recommend giving him some clicks (it's not behind the paywall) and reading what he wrote.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
User avatar
sergegva
Posts: 256
Joined: Sat Jun 18, 2016 9:12 pm

Re: Airbus stops accepting PW1100G engines

Thu Apr 26, 2018 8:07 pm

Has a resumption date for A320neo deliveries with Pratt engines been announced, or still nothing?
 
azjubilee
Posts: 3721
Joined: Sat Apr 29, 2000 5:26 am

Re: Airbus stops accepting PW1100G engines

Thu Apr 26, 2018 8:50 pm

HAL will take their 3rd 321 and the first since the engine issues in early May. So... yes, things are picking back up.
 
User avatar
lightsaber
Moderator
Posts: 20292
Joined: Wed Jan 19, 2005 10:55 pm

Re: Airbus stops accepting PW1100G engines

Thu Apr 26, 2018 10:36 pm

azjubilee wrote:
HAL will take their 3rd 321 and the first since the engine issues in early May. So... yes, things are picking back up.

Finally! Oh, the backlog...
Winter is coming.
 
azjubilee
Posts: 3721
Joined: Sat Apr 29, 2000 5:26 am

Re: Airbus stops accepting PW1100G engines

Thu Apr 26, 2018 10:50 pm

lightsaber wrote:
azjubilee wrote:
HAL will take their 3rd 321 and the first since the engine issues in early May. So... yes, things are picking back up.

Finally! Oh, the backlog...


Yeah... fast and furious from May! 9 planes to be delivered between May and November, 3 in July alone.
 
ap305
Posts: 1501
Joined: Mon Jan 03, 2000 4:03 am

Re: Airbus stops accepting PW1100G engines

Fri Apr 27, 2018 3:45 am

Go air pilots reporting that the pw engines were sluggish during a tcas advisory response....

http://timesofindia.indiatimes.com/busi ... 933301.cms
Racing, competing, is in my blood. It's part of me, it's part of my life; I've been doing it all my life. And it stands up before anything else- Ayrton Senna
 
User avatar
sergegva
Posts: 256
Joined: Sat Jun 18, 2016 9:12 pm

Re: Airbus stops accepting PW1100G engines

Mon Apr 30, 2018 10:12 am

N535VL, second A321neo for Volaris, with PW engines, was delivered on April 27th, 2 months after the last PW delivery (B-8367, first A321neo for China Southern Airlines).
 
User avatar
Channex757
Posts: 2412
Joined: Sat Jun 18, 2016 7:07 am

Re: Airbus stops accepting PW1100G engines

Mon Apr 30, 2018 11:40 am

ap305 wrote:
Go air pilots reporting that the pw engines were sluggish during a tcas advisory response....

http://timesofindia.indiatimes.com/busi ... 933301.cms

I wonder if this is just down to pilot perception? Larger fans (especially a geared turbofan) will behave very differently to the CEO motors.

Changes in power settings, especially sudden ones or ones made at altitude, may be very different in the way they spin up compared to the more compact engine designs with lower bypass.
 
Waterbomber
Posts: 849
Joined: Sat Jul 09, 2016 11:51 am

Re: Airbus stops accepting PW1100G engines

Mon Apr 30, 2018 1:30 pm

Channex757 wrote:
ap305 wrote:
Go air pilots reporting that the pw engines were sluggish during a tcas advisory response....

http://timesofindia.indiatimes.com/busi ... 933301.cms

I wonder if this is just down to pilot perception? Larger fans (especially a geared turbofan) will behave very differently to the CEO motors.

Changes in power settings, especially sudden ones or ones made at altitude, may be very different in the way they spin up compared to the more compact engine designs with lower bypass.


The guy was descending from FL370 and the traffic was at FL360. I sympathise about getting a climb TCAS RA at that altitude, but what is sluggish and what is normal at that altitude? It's not going to climb at 5000ft/min, if that's what he hoped for.
 
LewisNEO
Posts: 250
Joined: Thu Jan 05, 2017 12:08 pm

Re: Airbus stops accepting PW1100G engines

Mon Apr 30, 2018 3:34 pm

Waterbomber wrote:
Channex757 wrote:
ap305 wrote:
Go air pilots reporting that the pw engines were sluggish during a tcas advisory response....

http://timesofindia.indiatimes.com/busi ... 933301.cms

I wonder if this is just down to pilot perception? Larger fans (especially a geared turbofan) will behave very differently to the CEO motors.

Changes in power settings, especially sudden ones or ones made at altitude, may be very different in the way they spin up compared to the more compact engine designs with lower bypass.


The guy was descending from FL370 and the traffic was at FL360. I sympathise about getting a climb TCAS RA at that altitude, but what is sluggish and what is normal at that altitude? It's not going to climb at 5000ft/min, if that's what he hoped for.


To me, the whole argument about a "sluggish" engine sounds as a diversion of the real question/problem: why where the airplanes so dangerously close to each other? Last time I checked imho, it is the human being that steers the bird including the "to be sluggish or not to be sluggish" engine into a certain direction, assisted or given the tower's directions. I'd lean towards this direction in an investigation, of course dealing with/taking into account any (minor) side events. At least that's how I always used to advise at my former job regarding patientsafety in hospitals; a subject of which I was taught it had many similarities with flight traffic safety. :yes:
You are the wind beneath my wings.

Fokker 27, Bombardier Dash 8, Embraer 175 & 195, 727-200, 737-200 & -300 & -400 & -800, 747-400, 767-300, 767-400, DC 10-30, A320-200, A330-200, A330-300, A380.
 
User avatar
Channex757
Posts: 2412
Joined: Sat Jun 18, 2016 7:07 am

Re: Airbus stops accepting PW1100G engines

Mon Apr 30, 2018 10:27 pm

Waterbomber wrote:
Channex757 wrote:
ap305 wrote:
Go air pilots reporting that the pw engines were sluggish during a tcas advisory response....

http://timesofindia.indiatimes.com/busi ... 933301.cms

I wonder if this is just down to pilot perception? Larger fans (especially a geared turbofan) will behave very differently to the CEO motors.

Changes in power settings, especially sudden ones or ones made at altitude, may be very different in the way they spin up compared to the more compact engine designs with lower bypass.


The guy was descending from FL370 and the traffic was at FL360. I sympathise about getting a climb TCAS RA at that altitude, but what is sluggish and what is normal at that altitude? It's not going to climb at 5000ft/min, if that's what he hoped for.

This engine is essentially a smaller core driving a bigger fan through a gearbox. Of course it's going to behave differently to a V2500. That core has to work harder to spin the turbine and gearbox up faster.

The engine is optimised for the climb and cruise sectors, not aerobatics. To me this just sounds like nonsense. A bad workman blames his tools.....
 
User avatar
lightsaber
Moderator
Posts: 20292
Joined: Wed Jan 19, 2005 10:55 pm

Re: Airbus stops accepting PW1100G engines

Mon Apr 30, 2018 10:39 pm

Channex757 wrote:
Waterbomber wrote:
Channex757 wrote:
I wonder if this is just down to pilot perception? Larger fans (especially a geared turbofan) will behave very differently to the CEO motors.

Changes in power settings, especially sudden ones or ones made at altitude, may be very different in the way they spin up compared to the more compact engine designs with lower bypass.


The guy was descending from FL370 and the traffic was at FL360. I sympathise about getting a climb TCAS RA at that altitude, but what is sluggish and what is normal at that altitude? It's not going to climb at 5000ft/min, if that's what he hoped for.

This engine is essentially a smaller core driving a bigger fan through a gearbox. Of course it's going to behave differently to a V2500. That core has to work harder to spin the turbine and gearbox up faster.

The engine is optimised for the climb and cruise sectors, not aerobatics. To me this just sounds like nonsense. A bad workman blames his tools.....

To put another way, the core is more heavily loaded and so there is less surplus power at any setting to accelerate the engine.

My personal assumption is the PW1100G should have 4X to 6X the time constant of the V2500.

This is like someone complaining their turbocharger doesn't spin up as fast in 6th gear (economy) versus 4th gear... Ugh... Physics. Imagine a little 1.5L turbo sports car at 80kph (48 mph). In 6th gear, passing would be lame (PW1100G). In 4th? Zoom! Where the analogy breaks down is that eventually the PW1100G builds up to the same thrust (analogy broken after say ten seconds).

The planes shouldn't have been close. Pilots complained the JT8D has faster transients than the CFM-56 too!

Lightsaber
Winter is coming.

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos